Chemistry | NIST

<!DOCTYPE html> <html lang="en" dir="ltr" prefix="content: http://purl.org/rss/1.0/modules/content/ dc: http://purl.org/dc/terms/ foaf: http://xmlns.com/foaf/0.1/ og: http://ogp.me/ns# rdfs: http://www.w3.org/2000/01/rdf-schema# schema: http://schema.org/ sioc: http://rdfs.org/sioc/ns# sioct: http://rdfs.org/sioc/types# skos: http://www.w3.org/2004/02/skos/core# xsd: http://www.w3.org/2001/XMLSchema# "> <head><script type="text/javascript" src="/_static/js/bundle-playback.js?v=HxkREWBo" charset="utf-8"></script> <script type="text/javascript" src="/_static/js/wombat.js?v=txqj7nKC" charset="utf-8"></script> <script>window.RufflePlayer=window.RufflePlayer||{};window.RufflePlayer.config={"autoplay":"on","unmuteOverlay":"hidden"};</script> <script type="text/javascript" src="/_static/js/ruffle/ruffle.js"></script> <script type="text/javascript"> __wm.init("https://web.archive.org/web"); __wm.wombat("https://www.nist.gov/chemistry","20231003083231","https://web.archive.org/","web","/_static/", "1696321951"); </script> <link rel="stylesheet" type="text/css" href="/_static/css/banner-styles.css?v=S1zqJCYt" /> <link rel="stylesheet" type="text/css" href="/_static/css/iconochive.css?v=3PDvdIFv" />  <meta charset="utf-8"/><script type="text/javascript">(window.NREUM||(NREUM={})).init={ajax:{deny_list:["gov-bam.nr-data.net"]}};(window.NREUM||(NREUM={})).loader_config={licenseKey:"37b7ccb661",applicationID:"1089704227"};;/*! For license information please see nr-loader-rum-1.242.0.min.js.LICENSE.txt */ (()=>{"use strict";var e,t,n={234:(e,t,n)=>{n.d(t,{P_:()=>h,Mt:()=>m,C5:()=>s,DL:()=>w,OP:()=>j,lF:()=>N,Yu:()=>_,Dg:()=>v,CX:()=>c,GE:()=>A,sU:()=>T});var r=n(8632),i=n(9567);const a={beacon:r.ce.beacon,errorBeacon:r.ce.errorBeacon,licenseKey:void 0,applicationID:void 0,sa:void 0,queueTime:void 0,applicationTime:void 0,ttGuid:void 0,user:void 0,account:void 0,product:void 0,extra:void 0,jsAttributes:{},userAttributes:void 0,atts:void 0,transactionName:void 0,tNamePlain:void 0},o={};function s(e){if(!e)throw new Error("All info objects require an agent identifier!");if(!o[e])throw new Error("Info for ".concat(e," was never set"));return o[e]}function c(e,t){if(!e)throw new Error("All info objects require an agent identifier!");o[e]=(0,i.D)(t,a),(0,r.Qy)(e,o[e],"info")}const d=e=>{if(!e||"string"!=typeof e)return!1;try{document.createDocumentFragment().querySelector(e)}catch{return!1}return!0};var u=n(7056),l=n(50);const f=()=>{const e={mask_selector:"*",block_selector:"[data-nr-block]",mask_input_options:{color:!1,date:!1,"datetime-local":!1,email:!1,month:!1,number:!1,range:!1,search:!1,tel:!1,text:!1,time:!1,url:!1,week:!1,textarea:!1,select:!1,password:!0}};return{proxy:{assets:void 0,beacon:void 0},privacy:{cookies_enabled:!0},ajax:{deny_list:void 0,block_internal:!0,enabled:!0,harvestTimeSeconds:10,autoStart:!0},distributed_tracing:{enabled:void 0,exclude_newrelic_header:void 0,cors_use_newrelic_header:void 0,cors_use_tracecontext_headers:void 0,allowed_origins:void 0},session:{domain:void 0,expiresMs:u.oD,inactiveMs:u.Hb},ssl:void 0,obfuscate:void 0,jserrors:{enabled:!0,harvestTimeSeconds:10,autoStart:!0},metrics:{enabled:!0,autoStart:!0},page_action:{enabled:!0,harvestTimeSeconds:30,autoStart:!0},page_view_event:{enabled:!0,autoStart:!0},page_view_timing:{enabled:!0,harvestTimeSeconds:30,long_task:!1,autoStart:!0},session_trace:{enabled:!0,harvestTimeSeconds:10,autoStart:!0},harvest:{tooManyRequestsDelay:60},session_replay:{autoStart:!0,enabled:!1,harvestTimeSeconds:60,sampling_rate:50,error_sampling_rate:50,mask_all_inputs:!0,get mask_text_selector(){return e.mask_selector},set mask_text_selector(t){d(t)?e.mask_selector=t+",[data-nr-mask]":null===t?e.mask_selector=t:(0,l.Z)("An invalid session_replay.mask_selector was provided and will not be used",t)},get block_class(){return"nr-block"},get ignore_class(){return"nr-ignore"},get mask_text_class(){return"nr-mask"},get block_selector(){return e.block_selector},set block_selector(t){d(t)?e.block_selector+=",".concat(t):""!==t&&(0,l.Z)("An invalid session_replay.block_selector was provided and will not be used",t)},get mask_input_options(){return e.mask_input_options},set mask_input_options(t){t&&"object"==typeof t?e.mask_input_options={...t,password:!0}:(0,l.Z)("An invalid session_replay.mask_input_option was provided and will not be used",t)}},spa:{enabled:!0,harvestTimeSeconds:10,autoStart:!0}}},g={},p="All configuration objects require an agent identifier!";function h(e){if(!e)throw new Error(p);if(!g[e])throw new Error("Configuration for ".concat(e," was never set"));return g[e]}function v(e,t){if(!e)throw new Error(p);g[e]=(0,i.D)(t,f()),(0,r.Qy)(e,g[e],"config")}function m(e,t){if(!e)throw new Error(p);var n=h(e);if(n){for(var r=t.split("."),i=0;i<r.length-1;i++)if("object"!=typeof(n=n[r[i]]))return;n=n[r[r.length-1]]}return n}const b={accountID:void 0,trustKey:void 0,agentID:void 0,licenseKey:void 0,applicationID:void 0,xpid:void 0},y={};function w(e){if(!e)throw new Error("All loader-config objects require an agent identifier!");if(!y[e])throw new Error("LoaderConfig for ".concat(e," was never set"));return y[e]}function A(e,t){if(!e)throw new Error("All loader-config objects require an agent identifier!");y[e]=(0,i.D)(t,b),(0,r.Qy)(e,y[e],"loader_config")}const _=(0,r.mF)().o;var x=n(385),D=n(6818);const k={buildEnv:D.Re,customTransaction:void 0,disabled:!1,distMethod:D.gF,isolatedBacklog:!1,loaderType:void 0,maxBytes:3e4,offset:Math.floor(x._A?.performance?.timeOrigin||x._A?.performance?.timing?.navigationStart||Date.now()),onerror:void 0,origin:""+x._A.location,ptid:void 0,releaseIds:{},session:void 0,xhrWrappable:"function"==typeof x._A.XMLHttpRequest?.prototype?.addEventListener,version:D.q4,denyList:void 0},E={};function j(e){if(!e)throw new Error("All runtime objects require an agent identifier!");if(!E[e])throw new Error("Runtime for ".concat(e," was never set"));return E[e]}function T(e,t){if(!e)throw new Error("All runtime objects require an agent identifier!");E[e]=(0,i.D)(t,k),(0,r.Qy)(e,E[e],"runtime")}function N(e){return function(e){try{const t=s(e);return!!t.licenseKey&&!!t.errorBeacon&&!!t.applicationID}catch(e){return!1}}(e)}},9567:(e,t,n)=>{n.d(t,{D:()=>i});var r=n(50);function i(e,t){try{if(!e||"object"!=typeof e)return(0,r.Z)("Setting a Configurable requires an object as input");if(!t||"object"!=typeof t)return(0,r.Z)("Setting a Configurable requires a model to set its initial properties");const n=Object.create(Object.getPrototypeOf(t),Object.getOwnPropertyDescriptors(t)),a=0===Object.keys(n).length?e:n;for(let o in a)if(void 0!==e[o])try{"object"==typeof e[o]&&"object"==typeof t[o]?n[o]=i(e[o],t[o]):n[o]=e[o]}catch(e){(0,r.Z)("An error occurred while setting a property of a Configurable",e)}return n}catch(e){(0,r.Z)("An error occured while setting a Configurable",e)}}},6818:(e,t,n)=>{n.d(t,{Re:()=>i,gF:()=>a,q4:()=>r});const r="1.242.0",i="PROD",a="CDN"},385:(e,t,n)=>{n.d(t,{Nk:()=>u,Tt:()=>s,_A:()=>a,cv:()=>l,iS:()=>o,il:()=>r,ux:()=>c,v6:()=>i,w1:()=>d});const r="undefined"!=typeof window&&!!window.document,i="undefined"!=typeof WorkerGlobalScope&&("undefined"!=typeof self&&self instanceof WorkerGlobalScope&&self.navigator instanceof WorkerNavigator||"undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope&&globalThis.navigator instanceof WorkerNavigator),a=r?window:"undefined"!=typeof WorkerGlobalScope&&("undefined"!=typeof self&&self instanceof WorkerGlobalScope&&self||"undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope&&globalThis),o=Boolean("hidden"===a?.document?.visibilityState),s=(a?.location,/iPad|iPhone|iPod/.test(a.navigator?.userAgent)),c=s&&"undefined"==typeof SharedWorker,d=((()=>{const e=a.navigator?.userAgent?.match(/Firefox[/\s](\d+\.\d+)/);Array.isArray(e)&&e.length>=2&&e[1]})(),Boolean(r&&window.document.documentMode)),u=!!a.navigator?.sendBeacon,l=Math.floor(a?.performance?.timeOrigin||a?.performance?.timing?.navigationStart||Date.now())},1117:(e,t,n)=>{n.d(t,{w:()=>a});var r=n(50);const i={agentIdentifier:"",ee:void 0};class a{constructor(e){try{if("object"!=typeof e)return(0,r.Z)("shared context requires an object as input");this.sharedContext={},Object.assign(this.sharedContext,i),Object.entries(e).forEach((e=>{let[t,n]=e;Object.keys(i).includes(t)&&(this.sharedContext[t]=n)}))}catch(e){(0,r.Z)("An error occured while setting SharedContext",e)}}}},8e3:(e,t,n)=>{n.d(t,{L:()=>u,R:()=>c});var r=n(8325),i=n(1284),a=n(4322),o=n(3325);const s={};function c(e,t){const n={staged:!1,priority:o.p[t]||0};d(e),s[e].get(t)||s[e].set(t,n)}function d(e){e&&(s[e]||(s[e]=new Map))}function u(){let e=arguments.length>0&&void 0!==arguments[0]?arguments[0]:"",t=arguments.length>1&&void 0!==arguments[1]?arguments[1]:"feature";if(d(e),!e||!s[e].get(t))return o(t);s[e].get(t).staged=!0;const n=[...s[e]];function o(t){const n=e?r.ee.get(e):r.ee,o=a.X.handlers;if(n.backlog&&o){var s=n.backlog[t],c=o[t];if(c){for(var d=0;s&&d<s.length;++d)l(s[d],c);(0,i.D)(c,(function(e,t){(0,i.D)(t,(function(t,n){n[0].on(e,n[1])}))}))}delete o[t],n.backlog[t]=null,n.emit("drain-"+t,[])}}n.every((e=>{let[t,n]=e;return n.staged}))&&(n.sort(((e,t)=>e[1].priority-t[1].priority)),n.forEach((t=>{let[n]=t;s[e].delete(n),o(n)})))}function l(e,t){var n=e[1];(0,i.D)(t[n],(function(t,n){var r=e[0];if(n[0]===r){var i=n[1],a=e[3],o=e[2];i.apply(a,o)}}))}},8325:(e,t,n)=>{n.d(t,{A:()=>c,ee:()=>d});var r=n(8632),i=n(2210),a=n(234);class o{constructor(e){this.contextId=e}}var s=n(3117);const c="nr@context:".concat(s.a),d=function e(t,n){var r={},s={},u={},f=!1;try{f=16===n.length&&(0,a.OP)(n).isolatedBacklog}catch(e){}var g={on:h,addEventListener:h,removeEventListener:function(e,t){var n=r[e];if(!n)return;for(var i=0;i<n.length;i++)n[i]===t&&n.splice(i,1)},emit:function(e,n,r,i,a){!1!==a&&(a=!0);if(d.aborted&&!i)return;t&&a&&t.emit(e,n,r);for(var o=p(r),c=v(e),u=c.length,l=0;l<u;l++)c[l].apply(o,n);var f=b()[s[e]];f&&f.push([g,e,n,o]);return o},get:m,listeners:v,context:p,buffer:function(e,t){const n=b();if(t=t||"feature",g.aborted)return;Object.entries(e||{}).forEach((e=>{let[r,i]=e;s[i]=t,t in n||(n[t]=[])}))},abort:l,aborted:!1,isBuffering:function(e){return!!b()[s[e]]},debugId:n,backlog:f?{}:t&&"object"==typeof t.backlog?t.backlog:{}};return g;function p(e){return e&&e instanceof o?e:e?(0,i.X)(e,c,(()=>new o(c))):new o(c)}function h(e,t){r[e]=v(e).concat(t)}function v(e){return r[e]||[]}function m(t){return u[t]=u[t]||e(g,t)}function b(){return g.backlog}}(void 0,"globalEE"),u=(0,r.fP)();function l(){d.aborted=!0,d.backlog={}}u.ee||(u.ee=d)},5546:(e,t,n)=>{n.d(t,{E:()=>r,p:()=>i});var r=n(8325).ee.get("handle");function i(e,t,n,i,a){a?(a.buffer([e],i),a.emit(e,t,n)):(r.buffer([e],i),r.emit(e,t,n))}},4322:(e,t,n)=>{n.d(t,{X:()=>a});var r=n(5546);a.on=o;var i=a.handlers={};function a(e,t,n,a){o(a||r.E,i,e,t,n)}function o(e,t,n,i,a){a||(a="feature"),e||(e=r.E);var o=t[a]=t[a]||{};(o[n]=o[n]||[]).push([e,i])}},3239:(e,t,n)=>{n.d(t,{bP:()=>s,iz:()=>c,m$:()=>o});var r=n(385);let i=!1,a=!1;try{const e={get passive(){return i=!0,!1},get signal(){return a=!0,!1}};r._A.addEventListener("test",null,e),r._A.removeEventListener("test",null,e)}catch(e){}function o(e,t){return i||a?{capture:!!e,passive:i,signal:t}:!!e}function s(e,t){let n=arguments.length>2&&void 0!==arguments[2]&&arguments[2],r=arguments.length>3?arguments[3]:void 0;window.addEventListener(e,t,o(n,r))}function c(e,t){let n=arguments.length>2&&void 0!==arguments[2]&&arguments[2],r=arguments.length>3?arguments[3]:void 0;document.addEventListener(e,t,o(n,r))}},3117:(e,t,n)=>{n.d(t,{a:()=>r});const r=(0,n(4402).Rl)()},4402:(e,t,n)=>{n.d(t,{Rl:()=>o,ky:()=>s});var r=n(385);const i="xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx";function a(e,t){return e?15&e[t]:16*Math.random()|0}function o(){const e=r._A?.crypto||r._A?.msCrypto;let t,n=0;return e&&e.getRandomValues&&(t=e.getRandomValues(new Uint8Array(31))),i.split("").map((e=>"x"===e?a(t,++n).toString(16):"y"===e?(3&a()|8).toString(16):e)).join("")}function s(e){const t=r._A?.crypto||r._A?.msCrypto;let n,i=0;t&&t.getRandomValues&&(n=t.getRandomValues(new Uint8Array(31)));const o=[];for(var s=0;s<e;s++)o.push(a(n,++i).toString(16));return o.join("")}},7056:(e,t,n)=>{n.d(t,{Bq:()=>r,Hb:()=>a,oD:()=>i});const r="NRBA",i=144e5,a=18e5},7894:(e,t,n)=>{function r(){return Math.round(performance.now())}n.d(t,{z:()=>r})},50:(e,t,n)=>{function r(e,t){"function"==typeof console.warn&&(console.warn("New Relic: ".concat(e)),t&&console.warn(t))}n.d(t,{Z:()=>r})},2587:(e,t,n)=>{n.d(t,{N:()=>c,T:()=>d});var r=n(8325),i=n(5546),a=n(3325);const o={stn:[a.D.sessionTrace],err:[a.D.jserrors,a.D.metrics],ins:[a.D.pageAction],spa:[a.D.spa],sr:[a.D.sessionReplay,a.D.sessionTrace]},s=new Set;function c(e,t){const n=r.ee.get(t);e&&"object"==typeof e&&(s.has(t)||Object.entries(e).forEach((e=>{let[t,r]=e;o[t]?o[t].forEach((e=>{r?(0,i.p)("feat-"+t,[],void 0,e,n):(0,i.p)("block-"+t,[],void 0,e,n),(0,i.p)("rumresp-"+t,[Boolean(r)],void 0,e,n)})):r&&(0,i.p)("feat-"+t,[],void 0,void 0,n),d[t]=Boolean(r)})),Object.keys(o).forEach((e=>{void 0===d[e]&&(o[e]?.forEach((t=>(0,i.p)("rumresp-"+e,[!1],void 0,t,n))),d[e]=!1)})),s.add(t))}const d={}},2210:(e,t,n)=>{n.d(t,{X:()=>i});var r=Object.prototype.hasOwnProperty;function i(e,t,n){if(r.call(e,t))return e[t];var i=n();if(Object.defineProperty&&Object.keys)try{return Object.defineProperty(e,t,{value:i,writable:!0,enumerable:!1}),i}catch(e){}return e[t]=i,i}},1284:(e,t,n)=>{n.d(t,{D:()=>r});const r=(e,t)=>Object.entries(e||{}).map((e=>{let[n,r]=e;return t(n,r)}))},4351:(e,t,n)=>{n.d(t,{P:()=>a});var r=n(8325);const i=()=>{const e=new WeakSet;return(t,n)=>{if("object"==typeof n&&null!==n){if(e.has(n))return;e.add(n)}return n}};function a(e){try{return JSON.stringify(e,i())}catch(e){try{r.ee.emit("internal-error",[e])}catch(e){}}}},3960:(e,t,n)=>{n.d(t,{K:()=>o,b:()=>a});var r=n(3239);function i(){return"undefined"==typeof document||"complete"===document.readyState}function a(e,t){if(i())return e();(0,r.bP)("load",e,t)}function o(e){if(i())return e();(0,r.iz)("DOMContentLoaded",e)}},8632:(e,t,n)=>{n.d(t,{EZ:()=>d,Qy:()=>c,ce:()=>a,fP:()=>o,gG:()=>u,mF:()=>s});var r=n(7894),i=n(385);const a={beacon:"bam.nr-data.net",errorBeacon:"bam.nr-data.net"};function o(){return i._A.NREUM||(i._A.NREUM={}),void 0===i._A.newrelic&&(i._A.newrelic=i._A.NREUM),i._A.NREUM}function s(){let e=o();return e.o||(e.o={ST:i._A.setTimeout,SI:i._A.setImmediate,CT:i._A.clearTimeout,XHR:i._A.XMLHttpRequest,REQ:i._A.Request,EV:i._A.Event,PR:i._A.Promise,MO:i._A.MutationObserver,FETCH:i._A.fetch}),e}function c(e,t,n){let i=o();const a=i.initializedAgents||{},s=a[e]||{};return Object.keys(s).length||(s.initializedAt={ms:(0,r.z)(),date:new Date}),i.initializedAgents={...a,[e]:{...s,[n]:t}},i}function d(e,t){o()[e]=t}function u(){return function(){let e=o();const t=e.info||{};e.info={beacon:a.beacon,errorBeacon:a.errorBeacon,...t}}(),function(){let e=o();const t=e.init||{};e.init={...t}}(),s(),function(){let e=o();const t=e.loader_config||{};e.loader_config={...t}}(),o()}},7956:(e,t,n)=>{n.d(t,{N:()=>i});var r=n(3239);function i(e){let t=arguments.length>1&&void 0!==arguments[1]&&arguments[1],n=arguments.length>2?arguments[2]:void 0,i=arguments.length>3?arguments[3]:void 0;(0,r.iz)("visibilitychange",(function(){if(t)return void("hidden"===document.visibilityState&&e());e(document.visibilityState)}),n,i)}},3081:(e,t,n)=>{n.d(t,{gF:()=>a,mY:()=>i,t9:()=>r,vz:()=>s,xS:()=>o});const r=n(3325).D.metrics,i="sm",a="cm",o="storeSupportabilityMetrics",s="storeEventMetrics"},7633:(e,t,n)=>{n.d(t,{t:()=>r});const r=n(3325).D.pageViewEvent},9251:(e,t,n)=>{n.d(t,{t:()=>r});const r=n(3325).D.pageViewTiming},5938:(e,t,n)=>{n.d(t,{W:()=>a});var r=n(234),i=n(8325);class a{constructor(e,t,n){this.agentIdentifier=e,this.aggregator=t,this.ee=i.ee.get(e,(0,r.OP)(this.agentIdentifier).isolatedBacklog),this.featureName=n,this.blocked=!1}}},7530:(e,t,n)=>{n.d(t,{j:()=>b});var r=n(3325),i=n(234),a=n(5546),o=n(8325),s=n(7894),c=n(8e3),d=n(3960),u=n(385),l=n(50),f=n(3081),g=n(8632);function p(){const e=(0,g.gG)();["setErrorHandler","finished","addToTrace","inlineHit","addRelease","addPageAction","setCurrentRouteName","setPageViewName","setCustomAttribute","interaction","noticeError","setUserId","setApplicationVersion","start"].forEach((t=>{e[t]=function(){for(var n=arguments.length,r=new Array(n),i=0;i<n;i++)r[i]=arguments[i];return function(t){for(var n=arguments.length,r=new Array(n>1?n-1:0),i=1;i<n;i++)r[i-1]=arguments[i];let a=[];return Object.values(e.initializedAgents).forEach((e=>{e.exposed&&e.api[t]&&a.push(e.api[t](...r))})),a.length>1?a:a[0]}(t,...r)}}))}var h=n(2587);const v=e=>{n.p=e};let m=!1;function b(e){let t=arguments.length>1&&void 0!==arguments[1]?arguments[1]:{},b=arguments.length>2?arguments[2]:void 0,y=arguments.length>3?arguments[3]:void 0,{init:w,info:A,loader_config:_,runtime:x={loaderType:b},exposed:D=!0}=t;const k=(0,g.gG)();A||(w=k.init,A=k.info,_=k.loader_config),(0,i.Dg)(e,w||{}),(0,i.GE)(e,_||{}),A.jsAttributes??={},u.v6&&(A.jsAttributes.isWorker=!0),(0,i.CX)(e,A);const E=(0,i.P_)(e),j=[A.beacon,A.errorBeacon];m||(m=!0,E.proxy.assets&&(v(E.proxy.assets+"/"),j.push(E.proxy.assets)),E.proxy.beacon&&j.push(E.proxy.beacon)),x.denyList=[...E.ajax.deny_list||[],...E.ajax.block_internal?j:[]],(0,i.sU)(e,x),p();const T=function(e,t){t||(0,c.R)(e,"api");const g={};var p=o.ee.get(e),h=p.get("tracer"),v="api-",m=v+"ixn-";function b(t,n,r,a){const o=(0,i.C5)(e);return null===n?delete o.jsAttributes[t]:(0,i.CX)(e,{...o,jsAttributes:{...o.jsAttributes,[t]:n}}),A(v,r,!0,a||null===n?"session":void 0)(t,n)}function y(){}["setErrorHandler","finished","addToTrace","inlineHit","addRelease"].forEach((e=>{g[e]=A(v,e,!0,"api")})),g.addPageAction=A(v,"addPageAction",!0,r.D.pageAction),g.setCurrentRouteName=A(v,"routeName",!0,r.D.spa),g.setPageViewName=function(t,n){if("string"==typeof t)return"/"!==t.charAt(0)&&(t="/"+t),(0,i.OP)(e).customTransaction=(n||"https://web.archive.org/web/20231003083231/http://custom.transaction")+t,A(v,"setPageViewName",!0)()},g.setCustomAttribute=function(e,t){let n=arguments.length>2&&void 0!==arguments[2]&&arguments[2];if("string"==typeof e){if(["string","number"].includes(typeof t)||null===t)return b(e,t,"setCustomAttribute",n);(0,l.Z)("Failed to execute setCustomAttribute.\nNon-null value must be a string or number type, but a type of <".concat(typeof t,"> was provided."))}else(0,l.Z)("Failed to execute setCustomAttribute.\nName must be a string type, but a type of <".concat(typeof e,"> was provided."))},g.setUserId=function(e){if("string"==typeof e||null===e)return b("enduser.id",e,"setUserId",!0);(0,l.Z)("Failed to execute setUserId.\nNon-null value must be a string type, but a type of <".concat(typeof e,"> was provided."))},g.setApplicationVersion=function(e){if("string"==typeof e||null===e)return b("application.version",e,"setApplicationVersion",!1);(0,l.Z)("Failed to execute setApplicationVersion. Expected <String | null>, but got <".concat(typeof e,">."))},g.start=e=>{try{const t=e?"defined":"undefined";(0,a.p)(f.xS,["API/start/".concat(t,"/called")],void 0,r.D.metrics,p);const n=Object.values(r.D);if(void 0===e)e=n;else{if((e=Array.isArray(e)&&e.length?e:[e]).some((e=>!n.includes(e))))return(0,l.Z)("Invalid feature name supplied. Acceptable feature names are: ".concat(n));e.includes(r.D.pageViewEvent)||e.push(r.D.pageViewEvent)}e.forEach((e=>{p.emit("".concat(e,"-opt-in"))}))}catch(e){(0,l.Z)("An unexpected issue occurred",e)}},g.interaction=function(){return(new y).get()};var w=y.prototype={createTracer:function(e,t){var n={},i=this,o="function"==typeof t;return(0,a.p)(m+"tracer",[(0,s.z)(),e,n],i,r.D.spa,p),function(){if(h.emit((o?"":"no-")+"fn-start",[(0,s.z)(),i,o],n),o)try{return t.apply(this,arguments)}catch(e){throw h.emit("fn-err",[arguments,this,e],n),e}finally{h.emit("fn-end",[(0,s.z)()],n)}}}};function A(e,t,n,i){return function(){return(0,a.p)(f.xS,["API/"+t+"/called"],void 0,r.D.metrics,p),i&&(0,a.p)(e+t,[(0,s.z)(),...arguments],n?null:this,i,p),n?void 0:this}}function _(){n.e(75).then(n.bind(n,7438)).then((t=>{let{setAPI:n}=t;n(e),(0,c.L)(e,"api")})).catch((()=>(0,l.Z)("Downloading runtime APIs failed...")))}return["actionText","setName","setAttribute","save","ignore","onEnd","getContext","end","get"].forEach((e=>{w[e]=A(m,e,void 0,r.D.spa)})),g.noticeError=function(e,t){"string"==typeof e&&(e=new Error(e)),(0,a.p)(f.xS,["API/noticeError/called"],void 0,r.D.metrics,p),(0,a.p)("err",[e,(0,s.z)(),!1,t],void 0,r.D.jserrors,p)},u.il?(0,d.b)((()=>_()),!0):_(),g}(e,y);return(0,g.Qy)(e,T,"api"),(0,g.Qy)(e,D,"exposed"),(0,g.EZ)("activatedFeatures",h.T),T}},3325:(e,t,n)=>{n.d(t,{D:()=>r,p:()=>i});const r={ajax:"ajax",jserrors:"jserrors",metrics:"metrics",pageAction:"page_action",pageViewEvent:"page_view_event",pageViewTiming:"page_view_timing",sessionReplay:"session_replay",sessionTrace:"session_trace",spa:"spa"},i={[r.pageViewEvent]:1,[r.pageViewTiming]:2,[r.metrics]:3,[r.jserrors]:4,[r.ajax]:5,[r.sessionTrace]:6,[r.pageAction]:7,[r.spa]:8,[r.sessionReplay]:9}}},r={};function i(e){var t=r[e];if(void 0!==t)return t.exports;var a=r[e]={exports:{}};return n[e](a,a.exports,i),a.exports}i.m=n,i.d=(e,t)=>{for(var n in t)i.o(t,n)&&!i.o(e,n)&&Object.defineProperty(e,n,{enumerable:!0,get:t[n]})},i.f={},i.e=e=>Promise.all(Object.keys(i.f).reduce(((t,n)=>(i.f[n](e,t),t)),[])),i.u=e=>"nr-rum-1.242.0.min.js",i.o=(e,t)=>Object.prototype.hasOwnProperty.call(e,t),e={},t="NRBA-1.242.0.PROD:",i.l=(n,r,a,o)=>{if(e[n])e[n].push(r);else{var s,c;if(void 0!==a)for(var d=document.getElementsByTagName("script"),u=0;u<d.length;u++){var l=d[u];if(l.getAttribute("src")==n||l.getAttribute("data-webpack")==t+a){s=l;break}}s||(c=!0,(s=document.createElement("script")).charset="utf-8",s.timeout=120,i.nc&&s.setAttribute("nonce",i.nc),s.setAttribute("data-webpack",t+a),s.src=n),e[n]=[r];var f=(t,r)=>{s.onerror=s.onload=null,clearTimeout(g);var i=e[n];if(delete e[n],s.parentNode&&s.parentNode.removeChild(s),i&&i.forEach((e=>e(r))),t)return t(r)},g=setTimeout(f.bind(null,void 0,{type:"timeout",target:s}),12e4);s.onerror=f.bind(null,s.onerror),s.onload=f.bind(null,s.onload),c&&document.head.appendChild(s)}},i.r=e=>{"undefined"!=typeof Symbol&&Symbol.toStringTag&&Object.defineProperty(e,Symbol.toStringTag,{value:"Module"}),Object.defineProperty(e,"__esModule",{value:!0})},i.p="https://web.archive.org/web/20231003083231/https://js-agent.newrelic.com/",(()=>{var e={50:0,832:0};i.f.j=(t,n)=>{var r=i.o(e,t)?e[t]:void 0;if(0!==r)if(r)n.push(r[2]);else{var a=new Promise(((n,i)=>r=e[t]=[n,i]));n.push(r[2]=a);var o=i.p+i.u(t),s=new Error;i.l(o,(n=>{if(i.o(e,t)&&(0!==(r=e[t])&&(e[t]=void 0),r)){var a=n&&("load"===n.type?"missing":n.type),o=n&&n.target&&n.target.src;s.message="Loading chunk "+t+" failed.\n("+a+": "+o+")",s.name="ChunkLoadError",s.type=a,s.request=o,r[1](s)}}),"chunk-"+t,t)}};var t=(t,n)=>{var r,a,[o,s,c]=n,d=0;if(o.some((t=>0!==e[t]))){for(r in s)i.o(s,r)&&(i.m[r]=s[r]);if(c)c(i)}for(t&&t(n);d<o.length;d++)a=o[d],i.o(e,a)&&e[a]&&e[a][0](),e[a]=0},n=self["webpackChunk:NRBA-1.242.0.PROD"]=self["webpackChunk:NRBA-1.242.0.PROD"]||[];n.forEach(t.bind(null,0)),n.push=t.bind(null,n.push.bind(n))})(),(()=>{var e=i(50);class t{addPageAction(t,n){(0,e.Z)("Call to agent api addPageAction failed. The session trace feature is not currently initialized.")}setPageViewName(t,n){(0,e.Z)("Call to agent api setPageViewName failed. The page view feature is not currently initialized.")}setCustomAttribute(t,n,r){(0,e.Z)("Call to agent api setCustomAttribute failed. The js errors feature is not currently initialized.")}noticeError(t,n){(0,e.Z)("Call to agent api noticeError failed. The js errors feature is not currently initialized.")}setUserId(t){(0,e.Z)("Call to agent api setUserId failed. The js errors feature is not currently initialized.")}setApplicationVersion(t){(0,e.Z)("Call to agent api setApplicationVersion failed. The agent is not currently initialized.")}setErrorHandler(t){(0,e.Z)("Call to agent api setErrorHandler failed. The js errors feature is not currently initialized.")}finished(t){(0,e.Z)("Call to agent api finished failed. The page action feature is not currently initialized.")}addRelease(t,n){(0,e.Z)("Call to agent api addRelease failed. The agent is not currently initialized.")}start(t){(0,e.Z)("Call to agent api addRelease failed. The agent is not currently initialized.")}}var n=i(3325),r=i(234);const a=Object.values(n.D);function o(e){const t={};return a.forEach((n=>{t[n]=function(e,t){return!1!==(0,r.Mt)(t,"".concat(e,".enabled"))}(n,e)})),t}var s=i(7530);var c=i(8e3),d=i(5938),u=i(3960),l=i(385);class f extends d.W{constructor(e,t,n){let i=!(arguments.length>3&&void 0!==arguments[3])||arguments[3];super(e,t,n),this.auto=i,this.abortHandler=void 0,this.featAggregate=void 0,this.onAggregateImported=void 0,!1===(0,r.Mt)(this.agentIdentifier,"".concat(this.featureName,".autoStart"))&&(this.auto=!1),this.auto&&(0,c.R)(e,n)}importAggregator(){let t=arguments.length>0&&void 0!==arguments[0]?arguments[0]:{};if(this.featAggregate)return;if(!this.auto)return void this.ee.on("".concat(this.featureName,"-opt-in"),(()=>{(0,c.R)(this.agentIdentifier,this.featureName),this.auto=!0,this.importAggregator()}));const n=l.il&&!0===(0,r.Mt)(this.agentIdentifier,"privacy.cookies_enabled");let a;this.onAggregateImported=new Promise((e=>{a=e}));const o=async()=>{let r;try{if(n){const{setupAgentSession:e}=await i.e(75).then(i.bind(i,3228));r=e(this.agentIdentifier)}}catch(t){(0,e.Z)("A problem occurred when starting up session manager. This page will not start or extend any session.",t)}try{if(!this.shouldImportAgg(this.featureName,r))return(0,c.L)(this.agentIdentifier,this.featureName),void a(!1);const{lazyFeatureLoader:e}=await i.e(75).then(i.bind(i,8582)),{Aggregate:n}=await e(this.featureName,"aggregate");this.featAggregate=new n(this.agentIdentifier,this.aggregator,t),a(!0)}catch(t){(0,e.Z)("Downloading and initializing ".concat(this.featureName," failed..."),t),this.abortHandler?.(),(0,c.L)(this.agentIdentifier,this.featureName),a(!1)}};l.il?(0,u.b)((()=>o()),!0):o()}shouldImportAgg(e,t){return e!==n.D.sessionReplay||!!r.Yu.MO&&(!1!==(0,r.Mt)(this.agentIdentifier,"session_trace.enabled")&&(!!t?.isNew||!!t?.state.sessionReplay))}}var g=i(7633);class p extends f{static featureName=g.t;constructor(e,t){let n=!(arguments.length>2&&void 0!==arguments[2])||arguments[2];super(e,t,g.t,n),this.importAggregator()}}var h=i(1117),v=i(1284);class m extends h.w{constructor(e){super(e),this.aggregatedData={}}store(e,t,n,r,i){var a=this.getBucket(e,t,n,i);return a.metrics=function(e,t){t||(t={count:0});return t.count+=1,(0,v.D)(e,(function(e,n){t[e]=b(n,t[e])})),t}(r,a.metrics),a}merge(e,t,n,r,i){var a=this.getBucket(e,t,r,i);if(a.metrics){var o=a.metrics;o.count+=n.count,(0,v.D)(n,(function(e,t){if("count"!==e){var r=o[e],i=n[e];i&&!i.c?o[e]=b(i.t,r):o[e]=function(e,t){if(!t)return e;t.c||(t=y(t.t));return t.min=Math.min(e.min,t.min),t.max=Math.max(e.max,t.max),t.t+=e.t,t.sos+=e.sos,t.c+=e.c,t}(i,o[e])}}))}else a.metrics=n}storeMetric(e,t,n,r){var i=this.getBucket(e,t,n);return i.stats=b(r,i.stats),i}getBucket(e,t,n,r){this.aggregatedData[e]||(this.aggregatedData[e]={});var i=this.aggregatedData[e][t];return i||(i=this.aggregatedData[e][t]={params:n||{}},r&&(i.custom=r)),i}get(e,t){return t?this.aggregatedData[e]&&this.aggregatedData[e][t]:this.aggregatedData[e]}take(e){for(var t={},n="",r=!1,i=0;i<e.length;i++)t[n=e[i]]=w(this.aggregatedData[n]),t[n].length&&(r=!0),delete this.aggregatedData[n];return r?t:null}}function b(e,t){return null==e?function(e){e?e.c++:e={c:1};return e}(t):t?(t.c||(t=y(t.t)),t.c+=1,t.t+=e,t.sos+=e*e,e>t.max&&(t.max=e),e<t.min&&(t.min=e),t):{t:e}}function y(e){return{t:e,min:e,max:e,sos:e*e,c:1}}function w(e){return"object"!=typeof e?[]:(0,v.D)(e,A)}function A(e,t){return t}var _=i(8632),x=i(4402),D=i(4351);var k=i(5546),E=i(7956),j=i(3239),T=i(7894),N=i(9251);class S extends f{static featureName=N.t;constructor(e,t){let n=!(arguments.length>2&&void 0!==arguments[2])||arguments[2];super(e,t,N.t,n),l.il&&((0,E.N)((()=>(0,k.p)("docHidden",[(0,T.z)()],void 0,N.t,this.ee)),!0),(0,j.bP)("pagehide",(()=>(0,k.p)("winPagehide",[(0,T.z)()],void 0,N.t,this.ee))),this.importAggregator())}}var P=i(3081);class C extends f{static featureName=P.t9;constructor(e,t){let n=!(arguments.length>2&&void 0!==arguments[2])||arguments[2];super(e,t,P.t9,n),this.importAggregator()}}new class extends t{constructor(t){let n=arguments.length>1&&void 0!==arguments[1]?arguments[1]:(0,x.ky)(16);super(),l._A?(this.agentIdentifier=n,this.sharedAggregator=new m({agentIdentifier:this.agentIdentifier}),this.features={},this.desiredFeatures=new Set(t.features||[]),this.desiredFeatures.add(p),Object.assign(this,(0,s.j)(this.agentIdentifier,t,t.loaderType||"agent")),this.run()):(0,e.Z)("Failed to initial the agent. Could not determine the runtime environment.")}get config(){return{info:(0,r.C5)(this.agentIdentifier),init:(0,r.P_)(this.agentIdentifier),loader_config:(0,r.DL)(this.agentIdentifier),runtime:(0,r.OP)(this.agentIdentifier)}}run(){const t="features";try{const r=o(this.agentIdentifier),i=[...this.desiredFeatures];i.sort(((e,t)=>n.p[e.featureName]-n.p[t.featureName])),i.forEach((t=>{if(r[t.featureName]||t.featureName===n.D.pageViewEvent){const i=function(e){switch(e){case n.D.ajax:return[n.D.jserrors];case n.D.sessionTrace:return[n.D.ajax,n.D.pageViewEvent];case n.D.sessionReplay:return[n.D.sessionTrace];case n.D.pageViewTiming:return[n.D.pageViewEvent];default:return[]}}(t.featureName);i.every((e=>r[e]))||(0,e.Z)("".concat(t.featureName," is enabled but one or more dependent features has been disabled (").concat((0,D.P)(i),"). This may cause unintended consequences or missing data...")),this.features[t.featureName]=new t(this.agentIdentifier,this.sharedAggregator)}})),(0,_.Qy)(this.agentIdentifier,this.features,t)}catch(n){(0,e.Z)("Failed to initialize all enabled instrument classes (agent aborted) -",n);for(const e in this.features)this.features[e].abortHandler?.();const r=(0,_.fP)();return delete r.initializedAgents[this.agentIdentifier]?.api,delete r.initializedAgents[this.agentIdentifier]?.[t],delete this.sharedAggregator,r.ee?.abort(),delete r.ee?.get(this.agentIdentifier),!1}}addToTrace(t){(0,e.Z)("Call to agent api addToTrace failed. The page action feature is not currently initialized.")}setCurrentRouteName(t){(0,e.Z)("Call to agent api setCurrentRouteName failed. The spa feature is not currently initialized.")}interaction(){(0,e.Z)("Call to agent api interaction failed. The spa feature is not currently initialized.")}}({features:[p,S,C],loaderType:"lite"})})()})();</script> <noscript><style>form.antibot * :not(.antibot-message) { display: none !important; }</style> </noscript><script async src="https://web.archive.org/web/20231003083231js_/https://www.googletagmanager.com/gtag/js?id=G-HEQ0YF2VYL"></script> <script>window.dataLayer = window.dataLayer || [];function gtag(){dataLayer.push(arguments)};gtag("js", new Date());gtag("set", "developer_id.dMDhkMT", true);gtag('set', {'cookie_flags': 'SameSite=None;Secure', 'cookie_domain': 'www.nist.gov'});gtag("config", "G-HEQ0YF2VYL", {"groups":"default","page_placeholder":"PLACEHOLDER_page_location","link_attribution":true,"allow_ad_personalization_signals":false});gtag("event", "custom", {"node_title":"Chemistry","node_id":"1079101","content_type":"Topic Landing Page"});</script> <meta name="description" content="NIST develops the technology, measurement methods and standards to address the needs of the chemical industry."/> <link rel="canonical" href="https://web.archive.org/web/20231003083231/https://www.nist.gov/chemistry"/> <link rel="shortlink" href="https://web.archive.org/web/20231003083231/https://www.nist.gov/node/1079101"/> <meta name="citation_title" content="Chemistry | NIST"/> <meta property="og:site_name" content="NIST"/> <meta property="og:type" content="Article"/> <meta property="og:url" content="https://web.archive.org/web/20231003083231/https://www.nist.gov/chemistry"/> <meta property="og:title" content="Chemistry"/> <meta property="og:description" content="NIST develops the technology, measurement methods and standards to address the needs of the chemical industry."/> <meta property="og:image" content="https://web.archive.org/web/20231003083231im_/https://www.nist.gov/sites/default/files/images/2019/11/06/chemical_processing_ionic_liquids.jpg"/> <meta property="og:image:width" content="220"/> <meta property="og:image:height" content="170"/> <meta property="article:published_time" content="2016-06-30T13:50-04:00"/> <meta property="article:modified_time" content="2021-02-18T08:16-05:00"/> <meta name="dcterms.title" content="Chemistry"/> <meta name="dcterms.description" content="NIST develops the technology, measurement methods and standards to address the needs of the chemical industry."/> <meta name="dcterms.date" content="2016-06-30T13:50-04:00"/> <meta name="dcterms.type" content="text"/> <meta name="dcterms.format" content="text/html"/> <meta name="dcterms.identifier" content="https://www.nist.gov/chemistry"/> <meta name="dcterms.source" content="NIST"/> <meta name="dcterms.created" content="2016-06-30T13:50-04:00"/> <meta name="dcterms.modified" content="2021-02-18T08:16-05:00"/> <meta name="twitter:card" content="summary_large_image"/> <meta name="twitter:description" content="NIST develops the technology, measurement methods and standards to address the needs of the chemical industry."/> <meta name="twitter:site" content="NIST"/> <meta name="twitter:title" content="Chemistry"/> <meta name="twitter:url" content="https://web.archive.org/web/20231003083231im_/https://www.nist.gov/chemistry"/> <meta name="twitter:image" content="https://web.archive.org/web/20231003083231im_/https://www.nist.gov/sites/default/files/images/2019/11/06/chemical_processing_ionic_liquids.jpg"/> <meta name="twitter:image:height" content="170"/> <meta name="twitter:image:width" content="220"/> <meta name="google-site-verification" content="QMu0ODkER3rN5hLcMLqNVf7e3bkjYsNLTuhqfH48jCA"/> <meta name="Generator" content="Drupal 9 (https://www.drupal.org)"/> <meta name="MobileOptimized" content="width"/> <meta name="HandheldFriendly" content="true"/> <meta name="viewport" content="width=device-width, initial-scale=1.0"/> <meta name="nist_search_modified" class="elastic" content="2021-02-18T08:16:00-05:00"/> <script type="application/ld+json">{ "@context": "https://web.archive.org/web/20231003083231/https://schema.org", "@graph": [ { "@type": "Article", "headline": "Chemistry | NIST", "description": "NIST develops the technology, measurement methods and standards to address the needs of the chemical industry.", "image": { "@type": "ImageObject", "representativeOfPage": "True", "url": "https://web.archive.org/web/20231003083231/https://www.nist.gov/sites/default/files/images/2019/11/06/chemical_processing_ionic_liquids.jpg", "width": "220", "height": "170" }, "datePublished": "2016-06-30T13:50-04:00", "dateModified": "2021-02-18T08:16-05:00" } ] }</script> <meta name="nist_search_bundle" class="elastic" content="topic_landing_page"/> <link rel="icon" href="/web/20231003083231im_/https://www.nist.gov/themes/custom/nist_www/favicon.ico" type="image/vnd.microsoft.icon"/> <title>Chemistry | NIST</title> <link rel="stylesheet" media="all" href="/web/20231003083231cs_/https://www.nist.gov/sites/default/files/css/css_k4emWOv_NPa1WKIgS47VSQue1kN_PS3IgvacXjZ7MVo.css"/> <link rel="stylesheet" media="screen" href="/web/20231003083231cs_/https://www.nist.gov/sites/default/files/css/css_J7RuJ-PwWY36lMjcmfbU1Uvs509-G5bIcbR2QTQU4K0.css"/> <link rel="stylesheet" media="print" href="/web/20231003083231cs_/https://www.nist.gov/sites/default/files/css/css_zbjDhj-AmeVwgu9y0DlPwEfp7l-a5BpoK3MpoGmRB6o.css"/> <link rel="stylesheet" media="all" href="/web/20231003083231cs_/https://www.nist.gov/sites/default/files/css/css_PV0KmreUx3hVeYI6yGypf71UDz9BSQl1Z5DjiESDh-Y.css"/> <link rel="stylesheet" media="screen" href="/web/20231003083231cs_/https://www.nist.gov/sites/default/files/css/css_FXibUwfgVwlw4rjkYD-esMDIANHdek4UYQzEgNcqBEY.css"/> <script src="/web/20231003083231js_/https://www.nist.gov/sites/default/files/js/js_VDwaIMNiRtzQn-NZvj1F9loIzJ-i4yEDiruzS8Z6Ejo.js"></script> </head> <body class="node-1079101"> <a href="#main-content" class="visually-hidden focusable" data-elastic-exclude> Skip to main content </a> <div class="dialog-off-canvas-main-canvas" data-off-canvas-main-canvas>  <section data-elastic-exclude class="usa-banner" aria-label="Official government website"> <div class="usa-accordion"> <header class="usa-banner__header"> <div class="usa-banner__inner"> <div class="grid-col-auto"> <img class="usa-banner__header-flag" src="/web/20231003083231im_/https://www.nist.gov/libraries/nist-component-library/dist/img/us_flag_small.png" alt="U.S. flag"> </div> <div class="grid-col-fill tablet:grid-col-auto"> <p class="usa-banner__header-text">An official website of the United States government</p> <p class="usa-banner__header-action" aria-hidden="true">Here’s how you know</p> </div> <button class="usa-accordion__button usa-banner__button" aria-expanded="false" aria-controls="gov-banner-default"> <span class="usa-banner__button-text">Here’s how you know</span> </button> </div> </header> <div class="usa-banner__content usa-accordion__content" id="gov-banner-default"> <div class="grid-row grid-gap-lg"> <div class="usa-banner__guidance tablet:grid-col-6"> <img class="usa-banner__icon usa-media-block__img" src="/web/20231003083231im_/https://www.nist.gov/libraries/nist-component-library/dist/img/icon-dot-gov.svg" role="img" alt="" aria-hidden="true"> <div class="usa-media-block__body"> <p> <strong>Official websites use .gov</strong> <br/> A <strong>.gov</strong> website belongs to an official government organization in the United States. </p> </div> </div> <div class="usa-banner__guidance tablet:grid-col-6"> <img class="usa-banner__icon usa-media-block__img" src="/web/20231003083231im_/https://www.nist.gov/libraries/nist-component-library/dist/img/icon-https.svg" role="img" alt="" aria-hidden="true"> <div class="usa-media-block__body"> <p> <strong>Secure .gov websites use HTTPS</strong> <br/> A <strong>lock</strong> ( <span class="icon-lock"> <svg xmlns="http://www.w3.org/2000/svg" width="52" height="64" viewbox="0 0 52 64" class="usa-banner__lock-image" role="img" aria-labelledby="banner-lock-title banner-lock-description" focusable="false"> <title id="banner-lock-title">Lock</title> <desc id="banner-lock-description">A locked padlock</desc><path fill="#000000" fill-rule="evenodd" d="M26 0c10.493 0 19 8.507 19 19v9h3a4 4 0 0 1 4 4v28a4 4 0 0 1-4 4H4a4 4 0 0 1-4-4V32a4 4 0 0 1 4-4h3v-9C7 8.507 15.507 0 26 0zm0 8c-5.979 0-10.843 4.77-10.996 10.712L15 19v9h22v-9c0-6.075-4.925-11-11-11z"/></svg> </span> ) or <strong>https://</strong> means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites. </p> </div> </div> </div> </div> </div> </section>  <div data-elastic-exclude>  <div class="nist-print-header" style="display:none;"> <p class="nist-print-header__url">https://www.nist.gov/chemistry</p> <img class="nist-print-header__logo" width="289" height="38" src="/web/20231003083231im_/https://www.nist.gov/libraries/nist-component-library/dist/img/logo/nist_logo_sidestack.svg" alt="National Institute of Standards and Technology"/> </div> <div class="usa-overlay"></div> <header class="usa-header nist-header--www nist-header--minimal" role="banner"> <div class="usa-navbar"> <div class="usa-logo flex-fill"> <a href="/web/20231003083231/https://www.nist.gov/" title="National Institute of Standards and Technology" aria-label="Home"> <img src="/web/20231003083231im_/https://www.nist.gov/libraries/nist-component-library/dist/img/logo/logo.svg" alt="National Institute of Standards and Technology" width="300px" height="80px"/> </a> </div> <div class="usa-header__right grid-row flex-auto"> <div class="grid-col-fill nist-header__search-group"> <form class="usa-search usa-search--small" accept-charset="UTF-8" action="/web/20231003083231/https://www.nist.gov/search" id="search_form" method="get"> <div role="search"> <label class="usa-sr-only" for="search-form">Search NIST</label> <input class="usa-input" id="search-form" type="search" name="s" placeholder="Search NIST" required="" maxlength="128"> <button class="usa-button" type="submit"><img src="/web/20231003083231im_/https://www.nist.gov/libraries/nist-component-library/dist/img/usa-icons-bg/search--white.svg" class="usa-search__submit-icon" alt="Search"></button> </div> </form> </div> <div class="grid-col-auto padding-left-1"> <button class="usa-menu-btn">Menu</button> </div> </div> </div> <nav aria-label="Primary navigation" class="usa-nav"> <div class="usa-nav__inner"> <button class="usa-nav__close">Close</button> <ul class="usa-nav__primary usa-accordion"> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link usa-current" aria-expanded="false" aria-controls="primary_menu-1"><span>Topics</span></button> <div id="primary_menu-1" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/topics" class="usa-nav__link">All Topics</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/advanced-communications" class="usa-nav__link">Advanced communications</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/artificial-intelligence" class="usa-nav__link">Artificial intelligence</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/bioscience" class="usa-nav__link">Bioscience</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/buildings-construction" class="usa-nav__link">Buildings and construction</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/chemistry" class="usa-nav__link usa-current">Chemistry</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/climate" class="usa-nav__link">Climate</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/cybersecurity" class="usa-nav__link">Cybersecurity</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/electronics" class="usa-nav__link">Electronics</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/energy" class="usa-nav__link">Energy</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/environment" class="usa-nav__link">Environment</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/fire" class="usa-nav__link">Fire</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/forensic-science" class="usa-nav__link">Forensic science</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/health" class="usa-nav__link">Health</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/information-technology" class="usa-nav__link">Information technology</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/infrastructure" class="usa-nav__link">Infrastructure</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/manufacturing" class="usa-nav__link">Manufacturing</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/materials" class="usa-nav__link">Materials</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/mathematics-statistics" class="usa-nav__link">Mathematics and statistics</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/metrology" class="usa-nav__link">Metrology</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/nanotechnology" class="usa-nav__link">Nanotechnology</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/neutron-research" class="usa-nav__link">Neutron research</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/performance-excellence" class="usa-nav__link">Performance excellence</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/physics" class="usa-nav__link">Physics</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/public-safety" class="usa-nav__link">Public safety</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/resilience" class="usa-nav__link">Resilience</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/standards" class="usa-nav__link">Standards</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/transportation" class="usa-nav__link">Transportation</a> </li> </ul> </div> </div> </div> </li> <li class="usa-nav__primary-item"> <a class="usa-nav__link" href="/web/20231003083231/https://www.nist.gov/publications">Publications</a> </li> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-3"><span>Labs & Major Programs</span></button> <div id="primary_menu-3" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/labs-major-programs/laboratories" class="usa-nav__link">Laboratories</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20231003083231/https://www.nist.gov/ctl" class="usa-nav__link">Communications Technology Laboratory</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/el" class="usa-nav__link">Engineering Laboratory</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/itl" class="usa-nav__link">Information Technology Laboratory</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/mml" class="usa-nav__link">Material Measurement Laboratory</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/pml" class="usa-nav__link">Physical Measurement Laboratory</a> </li> </ul> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/labs-major-programs/user-facilities" class="usa-nav__link">User Facilities</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20231003083231/https://www.nist.gov/ncnr" class="usa-nav__link">NIST Center for Neutron Research</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/cnst" class="usa-nav__link">CNST NanoFab</a> </li> </ul> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/labs-major-programs/research-test-beds" class="usa-nav__link">Research Test Beds</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/laboratories/projects-programs" class="usa-nav__link">Research Projects</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/laboratories/tools-instruments" class="usa-nav__link">Tools & Instruments</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/labs-major-programs/major-programs" class="usa-nav__link">Major Programs</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20231003083231/https://www.nist.gov/baldrige" class="usa-nav__link">Baldrige Performance Excellence Program</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/chips" class="usa-nav__link">CHIPS for America Initiative</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/mep" class="usa-nav__link">Manufacturing Extension Partnership (MEP)</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/oam" class="usa-nav__link">Office of Advanced Manufacturing</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/spo" class="usa-nav__link">Special Programs Office</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/tpo" class="usa-nav__link">Technology Partnerships Office</a> </li> </ul> </li> </ul> </div> </div> </div> </li> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-4"><span>Services & Resources</span></button> <div id="primary_menu-4" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/services-resources/standards-and-measurements" class="usa-nav__link">Standards and Measurements</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20231003083231/https://www.nist.gov/calibrations" class="usa-nav__link">Calibration Services</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/nvlap" class="usa-nav__link">Laboratory Accreditation (NVLAP)</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/nist-quality-system" class="usa-nav__link">Quality System</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/srm" class="usa-nav__link">Standard Reference Materials (SRMs)</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/standardsgov" class="usa-nav__link">Standards.gov</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/pml/time-and-frequency-division/time-services" class="usa-nav__link">Time Services</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/pml/owm" class="usa-nav__link">Office of Weights and Measures</a> </li> </ul> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/services-resources/software" class="usa-nav__link">Software</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/data" class="usa-nav__link">Data</a> <ul class="usa-nav__submenu-list"> <li> <a href="https://web.archive.org/web/20231003083231/https://webbook.nist.gov/chemistry/" class="usa-nav__link">Chemistry WebBook</a> </li> <li> <a href="https://web.archive.org/web/20231003083231/https://nvd.nist.gov/" class="usa-nav__link">National Vulnerability Database</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/pml/productsservices/physical-reference-data" class="usa-nav__link">Physical Reference Data</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/srd" class="usa-nav__link">Standard Reference Data (SRD)</a> </li> </ul> </li> <li class="usa-nav__submenu-item"> <a href="https://web.archive.org/web/20231003083231/https://www.nist.gov/shop" class="usa-nav__link">Storefront</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/tpo" class="usa-nav__link">License & Patents</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="https://web.archive.org/web/20231003083231/https://csrc.nist.gov/" class="usa-nav__link">Computer Security Resource Center (CSRC)</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/nist-research-library" class="usa-nav__link">NIST Research Library</a> </li> </ul> </div> </div> </div> </li> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-5"><span>News & Events</span></button> <div id="primary_menu-5" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/news-events/news" class="usa-nav__link">News</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/news-events/events" class="usa-nav__link">Events</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/blogs" class="usa-nav__link">Blogs</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/feature-stories" class="usa-nav__link">Feature Stories</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/awards" class="usa-nav__link">Awards</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/video-gallery" class="usa-nav__link">Video Gallery</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/image-gallery" class="usa-nav__link">Image Gallery</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/pao/media-contacts" class="usa-nav__link">Media Contacts</a> </li> </ul> </div> </div> </div> </li> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-6"><span>About NIST</span></button> <div id="primary_menu-6" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/about-nist" class="usa-nav__link">About Us</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/about-nist/contact-us" class="usa-nav__link">Contact Us</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/about-nist/visit" class="usa-nav__link">Visit</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/careers" class="usa-nav__link">Careers</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/director/nist-organization-structure" class="usa-nav__link">Our Organization</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20231003083231/https://www.nist.gov/director" class="usa-nav__link">Office of the Director</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/director/nist-organization-structure/budget-planning" class="usa-nav__link">Budget & Planning</a> </li> </ul> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/about-nist/work-nist" class="usa-nav__link">Work with NIST</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/history" class="usa-nav__link">History</a> <ul class="usa-nav__submenu-list"> <li> <a href="https://web.archive.org/web/20231003083231/http://nistdigitalarchives.contentdm.oclc.org/" class="usa-nav__link">NIST Digital Archives</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/nist-museum" class="usa-nav__link">NIST Museum</a> </li> <li> <a href="/web/20231003083231/https://www.nist.gov/nist-and-nobel" class="usa-nav__link">NIST and the Nobel</a> </li> </ul> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231003083231/https://www.nist.gov/education" class="usa-nav__link">Educational Resources</a> </li> </ul> </div> </div> </div> </li> </ul> </div> </nav> </header>  </div> <div class="grid-container"> <div data-drupal-messages-fallback class="hidden"></div> </div> <div id="block-nist-www-content" class="nist-block"> <section class="nist-page__content usa-section clearfix"> <a id="main-content" tabindex="-1"></a> <div> <div class="nist-section-header nist-section-header--topic nist-section-header--hero"> <div class="nist-section-header__hero-img"> <div class="nist-block nist-block--no-margin"> <div class="entity-reference"> <img loading="lazy" src="/web/20231003083231im_/https://www.nist.gov/sites/default/files/images/2021/02/18/Chemistry_1200x248.png" width="1200" height="248" alt="colorful blobs on a black background with colorful netting around it." typeof="foaf:Image"/> </div> </div> </div> <div class="nist-section-header__main grid-container"> <div class="grid-row"> <div class="nist-section-header__title"> <h1 class="nist-page__title">Chemistry</h1> </div> </div> </div> </div> </div> <div class="grid-container"> <div class="nist-page__region nist-page__region--topic-description padding-top-4 margin-top-1"> <div class="nist-region-heading"> <h2>Overview</h2> </div> <div class="grid-row"> <div class="tablet:grid-col-8 padding-right-5 margin-bottom-4"> <div class="text-with-summary"> <p>From the food we eat and the pharmaceuticals doctors prescribe to the paints and fuel additives we use, the NIST develops the technology, measurement methods and standards to address the needs of the chemical industry.</p> </div> </div> <div class="tablet:grid-col-4"> <div class="nist-block nist-block--no-margin"> <h2 class="nist-block__title">Featured Content</h2> <div class="nist-field nist-field--label-hidden nist-field--link-list link font-sans-sm"> <div class="nist-field__items"> <div class="nist-field__item"><a href="/web/20231003083231/https://www.nist.gov/nist-and-nobel/dan-shechtman">NIST and the Nobel: Dan Shechtman</a></div> <div class="nist-field__item"><a href="/web/20231003083231/https://www.nist.gov/si-redefinition/redefining-mole">SI Redefinition: The Mole</a></div> <div class="nist-field__item"><a href="/web/20231003083231/https://www.nist.gov/feature-stories/each-mammal-its-milk">To Each Mammal, Its Milk (photo essay)</a></div> </div> </div> </div> </div> </div> </div> </div> <div class="bg-base-lightest padding-y-5 margin-y-4"> <div class="nist-page__region nist-page__region--topic-list grid-container"> <div class="views-element-container nist-block margin-bottom-0"> <div><div class="js-view-dom-id-dcba4a3835707dfd9a904a7337addfb2c4931ebb6768c73e31f3d146a55d8e95"> <div class="nist-block margin-bottom-0"> <div class="nist-region-heading"> <h2>Chemistry Topics</h2> </div> <ul class="add-list-reset link-list"> <div class="grid-row"> <div class="tablet:grid-col-6"> <li class="font-sans-md padding-bottom-205"><div class="views-field views-field-field-shared-section"><div class="field-content nist-icon nist-icon--before nist-icon--arrow-right2"><a href="/web/20231003083231/https://www.nist.gov/analytical-chemistry" hreflang="en">Analytical chemistry</a></div></div></li> </div> <div class="tablet:grid-col-6"> <li class="font-sans-md padding-bottom-205"><div class="views-field views-field-field-shared-section"><div class="field-content nist-icon nist-icon--before nist-icon--arrow-right2"><a href="/web/20231003083231/https://www.nist.gov/chemical-engineering-processing" hreflang="en">Chemical engineering & processing</a></div></div></li> </div> <div class="tablet:grid-col-6"> <li class="font-sans-md padding-bottom-205"><div class="views-field views-field-field-shared-section"><div class="field-content nist-icon nist-icon--before nist-icon--arrow-right2"><a href="/web/20231003083231/https://www.nist.gov/chemical-thermodynamics-chemical-properties" hreflang="en">Chemical thermodynamics & chemical properties</a></div></div></li> </div> <div class="tablet:grid-col-6"> <li class="font-sans-md padding-bottom-205"><div class="views-field views-field-field-shared-section"><div class="field-content nist-icon nist-icon--before nist-icon--arrow-right2"><a href="/web/20231003083231/https://www.nist.gov/molecular-characterization" hreflang="en">Molecular characterization</a></div></div></li> </div> <div class="tablet:grid-col-6"> <li class="font-sans-md padding-bottom-205"><div class="views-field views-field-field-shared-section"><div class="field-content nist-icon nist-icon--before nist-icon--arrow-right2"><a href="/web/20231003083231/https://www.nist.gov/theoretical-chemistry-modeling" hreflang="en">Theoretical chemistry & modeling</a></div></div></li> </div> <div class="tablet:grid-col-6"> <li class="font-sans-md padding-bottom-205"><div class="views-field views-field-field-shared-section"><div class="field-content nist-icon nist-icon--before nist-icon--arrow-right2"><a href="/web/20231003083231/https://www.nist.gov/thermochemical-properties" hreflang="en">Thermochemical properties</a></div></div></li> </div> </div> </ul> </div> </div> </div> </div> </div> </div> <div class="nist-page__region nist-page__region--main"> <div class="nist-block"> <div class="grid-container margin-y-5"> <div class="paragraph paragraph--type--topic-research paragraph--view-mode--default"> <div class="nist-region-heading"> <h2>The Research</h2> </div> <div class="grid-row"> <div class="tablet:grid-col-8 padding-right-5 margin-y-2"> <h2 class="nist-block__title">Projects & Programs</h2> <article role="article" about="/programs-projects/chemical-foundations-cannabis-breathalyzer" class="nist-teaser"> <div class="nist-teaser__image"> <div class="entity-reference"> <a href="/web/20231003083231/https://www.nist.gov/programs-projects/chemical-foundations-cannabis-breathalyzer" hreflang="en"><img loading="lazy" src="/web/20231003083231im_/https://www.nist.gov/sites/default/files/styles/thumbnail/public/images/2020/07/16/Cannabis%20Buds.jpeg?itok=I3WFsLdU" width="100" height="67" alt="Cannabis Buds" typeof="foaf:Image"/> </a> </div> </div> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20231003083231/https://www.nist.gov/programs-projects/chemical-foundations-cannabis-breathalyzer"><span>Chemical Foundations for a Cannabis Breathalyzer</span> </a></h3> <div class="nist-teaser__type"> <div class="nist-badge display-inline-block margin-y-1 nist-badge--blue boolean">Ongoing</div> </div> </header> <div class="nist-teaser__content"> <div class="text-long"> Founded in 2019, this program was motivated by the rapid decriminalization of recreational and medical cannabis by state governments. This has led to extensive </div> </div> </div> </article> <article role="article" about="/programs-projects/development-methods-measurement-vitamin-d-and-its-metabolites-foods-fortified" class="nist-teaser"> <div class="nist-teaser__image"> <div class="entity-reference"> <a href="/web/20231003083231/https://www.nist.gov/programs-projects/development-methods-measurement-vitamin-d-and-its-metabolites-foods-fortified" hreflang="en"><img loading="lazy" src="/web/20231003083231im_/https://www.nist.gov/sites/default/files/styles/thumbnail/public/images/2018/09/27/triangle_with_vit_d_srms.png?itok=DGWoDSRo" width="100" height="87" alt="Triangle with Vit D SRMs" typeof="foaf:Image"/> </a> </div> </div> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20231003083231/https://www.nist.gov/programs-projects/development-methods-measurement-vitamin-d-and-its-metabolites-foods-fortified"><span>Development of Methods for Measurement of Vitamin D and its Metabolites in Foods, Fortified Foods, and Dietary Supplements</span> </a></h3> <div class="nist-teaser__type"> <div class="nist-badge display-inline-block margin-y-1 nist-badge--blue boolean">Ongoing</div> </div> </header> <div class="nist-teaser__content"> <div class="text-long"> Vitamin D is a fat-soluble vitamin that is essential for bone health. Vitamin D deficiency is associated with muscle weakness and osteoporosis and can </div> </div> </div> </article> <article role="article" about="/programs-projects/differential-absorption-lidar-detection-and-quantification-greenhouse-gases" class="nist-teaser"> <div class="nist-teaser__image"> <div class="entity-reference"> <a href="/web/20231003083231/https://www.nist.gov/programs-projects/differential-absorption-lidar-detection-and-quantification-greenhouse-gases" hreflang="en"><img loading="lazy" src="/web/20231003083231im_/https://www.nist.gov/sites/default/files/styles/thumbnail/public/images/2019/07/23/smokestack_nagy_sm_1.jpg?itok=7sWNc7UI" width="100" height="100" alt="smokestack" typeof="foaf:Image"/> </a> </div> </div> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20231003083231/https://www.nist.gov/programs-projects/differential-absorption-lidar-detection-and-quantification-greenhouse-gases"><span>Differential absorption LIDAR for the detection and quantification of greenhouse gases</span> </a></h3> <div class="nist-teaser__type"> <div class="nist-badge display-inline-block margin-y-1 nist-badge--blue boolean">Ongoing</div> </div> </header> <div class="nist-teaser__content"> <div class="text-long"> We are developing a method for accurately quantifying greenhouse gas emissions from natural and anthropogenic sources and sinks to meet the requirements for </div> </div> </div> </article> <div class="link-list"><a href="/web/20231003083231/https://www.nist.gov/laboratories/projects-programs/topic/248416">View All Projects/Programs</a></div> </div> <div class="tablet:grid-col-4 margin-y-2"> <h2 class="nist-block__title">Additional Resources Links</h2> <div class="nist-field nist-field--label-hidden nist-field--link-list link nist-field--link-list font-sans-sm"> <div class="nist-field__items"> <div class="nist-field__item"><a href="/web/20231003083231/https://www.nist.gov/publications/search?ta%5B0%5D=248416&ta%5B1%5D=248416">Publications</a></div> <div class="nist-field__item"><a href="/web/20231003083231/https://www.nist.gov/services-resources/software?k=&d%5Bmin%5D=&d%5Bmax%5D=&a%5B0%5D=248416&a%5B1%5D=248416&tag=">Software</a></div> <div class="nist-field__item"><a href="/web/20231003083231/https://www.nist.gov/laboratories/tools-instruments?k=&a%5B0%5D=248416&a%5B1%5D=248416&o=All&tag=">Tools & Instruments</a></div> </div> </div> </div> </div> </div> </div> <div class="paragraph paragraph--type--topic-featured paragraph--view-mode--default nist-content-row--width-full bg-base-lightest margin-y-5"> <div class="grid-container"> <div class="nist-card nist-card--horizontal nist-card--horizontal-full nist-card--base-lightest"> <div class="nist-card__inner"> <div class="nist-card__image"> <a href="/web/20231003083231/https://www.nist.gov/blogs/taking-measure/shaping-future-nist-mass-spectral-library"> <div class="entity-reference"> <figure class="nist-image"> <img src="/web/20231003083231im_/https://www.nist.gov/sites/default/files/styles/800w_x_400h/public/images/2020/06/09/Mass%20Spec%20Database%20featured%20image.jpg.webp?itok=FtURj_Ra" width="800" height="400" alt="Tytus Mak sitting at his desk and while colleague Arun Moorthy and he look at a computer screen" title="Tytus Mak and Arun Moorthy" loading="lazy" typeof="foaf:Image"/> <figcaption class="nist-image__caption"> <div data-caption-editable="true" class="nist-image__caption-content"> </div> </figcaption> </figure> </div> </a> </div> <div class="nist-card__title"> <h3> Shaping the Future of the NIST Mass Spectral Library </h3> </div> <div class="nist-card__content"> <div class="text-long"><p>When one thinks of mass spectral libraries — well, let’s be honest here, the very idea of mass spectral libraries will never cross most people’s minds, even most scientists’. But that’s true for most of the seemingly esoteric things that many of us at the National Institute of Standards and Technology (NIST) have devoted our careers to. And though many of us have often struggled to explain the nature of our work to friends and loved ones (and more often than not failed to elicit excitement), the importance of NIST’s work cannot be overstated. This is very much true for what we call the NIST Standard Reference Database 1A, more commonly known as the <a data-entity-substitution="canonical" data-entity-type="node" data-entity-uuid="926f4ca6-7252-419c-967c-48f118824259" href="/web/20231003083231/https://www.nist.gov/srd/nist-standard-reference-database-1a" title="NIST Standard Reference Database 1A">NIST Mass Spectral Library</a>.</p> <p>This year marks the eighth release of the library, which includes over 2 million mass spectra measured for over 350,000 chemical compounds. </p></div> </div> <div class="nist-card__links"> <div class="nist-card__button"> <a href="/web/20231003083231/https://www.nist.gov/blogs/taking-measure/shaping-future-nist-mass-spectral-library" class="usa-button ">Read the full blog</a> </div> </div> </div> </div> </div> </div> <div class="grid-container margin-y-4"> <div class="nist-region-heading"> <h2>News</h2> </div> <div class="paragraph paragraph--type--dynamic-news-list-topic paragraph--view-mode--default"> <div class="views-element-container"><div class="js-view-dom-id-8f83d6550650f149ee4f83ba288ae7d3e2fa1b5721af9a4b7fdfae6876254422"> <div class="grid-row grid-gap-2"> <div class="nist-card tablet:grid-col-4 nist-card--topic "> <div class="nist-card__inner"> <div class="nist-card__image"> <a href="/web/20231003083231/https://www.nist.gov/news-events/news/2023/09/new-nist-method-can-better-identify-sneaky-sugars-viruses-spiky-weapons"> <div class="entity-reference"> <img loading="lazy" src="/web/20231003083231im_/https://www.nist.gov/sites/default/files/styles/800w_x_400h/public/images/2023/09/27/Covid-Glucose.png.webp?itok=hCTkwX1L" width="800" height="400" alt="A close-up of a virus particle shows spikes protruding from the particle's surface and blobby sugars that cling to the spikes." typeof="foaf:Image"/> </div> </a> </div> <div class="nist-card__title padding-y-5"> <h3><span property="schema:name">New NIST Method Can Better Identify Sneaky Sugars on Viruses’ Spiky Weapons</span> </h3> </div> <div class="nist-card__links"> <div class="nist-card__button"> <a href="/web/20231003083231/https://www.nist.gov/news-events/news/2023/09/new-nist-method-can-better-identify-sneaky-sugars-viruses-spiky-weapons" class="usa-button ">Read more</a> </div> </div> </div> </div> <div class="nist-card tablet:grid-col-4 nist-card--topic "> <div class="nist-card__inner"> <div class="nist-card__image"> <a href="/web/20231003083231/https://www.nist.gov/news-events/news/2023/09/spotlight-postdoctoral-researcher-ana-morales-and-nanoscale-plastics"> <div class="entity-reference"> <img loading="lazy" src="/web/20231003083231im_/https://www.nist.gov/sites/default/files/styles/800w_x_400h/public/images/2023/09/22/DSC_2634.jpg.webp?itok=HRv-R37G" width="800" height="400" alt="Woman in safety glasses stands next to an enclosed space with scientific equipment inside." typeof="foaf:Image"/> </div> </a> </div> <div class="nist-card__title padding-y-5"> <h3><span property="schema:name">Spotlight: Postdoctoral Researcher Ana Morales and the Nanoscale Plastics Pervading Our World</span> </h3> </div> <div class="nist-card__links"> <div class="nist-card__button"> <a href="/web/20231003083231/https://www.nist.gov/news-events/news/2023/09/spotlight-postdoctoral-researcher-ana-morales-and-nanoscale-plastics" class="usa-button ">Read more</a> </div> </div> </div> </div> <div class="nist-card tablet:grid-col-4 nist-card--topic "> <div class="nist-card__inner"> <div class="nist-card__image"> <a href="/web/20231003083231/https://www.nist.gov/news-events/news/2023/09/nist-researchers-develop-standards-help-eliminate-forever-chemicals"> <div class="entity-reference"> <img loading="lazy" src="/web/20231003083231im_/https://www.nist.gov/sites/default/files/styles/800w_x_400h/public/images/2023/09/11/thumbnail_IMG_7580.jpg.webp?itok=FL95K8Rn" width="800" height="400" alt="Four small dark glass ampules stand on a lab table, market with skull and crossbones danger icons. " typeof="foaf:Image"/> </div> </a> </div> <div class="nist-card__title padding-y-5"> <h3><span property="schema:name">NIST Researchers Develop Standards to Help Eliminate ‘Forever Chemicals’ in Firefighting Foams</span> </h3> </div> <div class="nist-card__links"> <div class="nist-card__button"> <a href="/web/20231003083231/https://www.nist.gov/news-events/news/2023/09/nist-researchers-develop-standards-help-eliminate-forever-chemicals" class="usa-button ">Read more</a> </div> </div> </div> </div> </div> <footer> <div class="link-list"><a href="/web/20231003083231/https://www.nist.gov/news-events/news-updates/topic/248416">View All News and Updates</a></div> </footer> </div> </div> </div> </div> <div class="padding-5 bg-primary-dark"> <h2 class="text-white text-center">Stay in Touch</h2> <p class="text-white text-center">Sign up for our newsletter to stay up to date with the latest research, trends, and news for Chemistry.</p> <form action="https://web.archive.org/web/20231003083231/https://public.govdelivery.com/accounts/USNIST/subscribers/qualify" accept-charset="UTF-8" method="post"> <input name="utf8" type="hidden" value="✓"/> <input type="hidden" name="topic_id" id="topic_id" value="USNIST_7"/> <div class="grid-row grid-gap-1 flex flex-justify-center"> <div class="tablet:grid-col-3"> <label class="usa-sr-only" for="email">Enter Email Address</label> <input class="usa-input" type="email" name="email" id="email" placeholder="Enter your email"> </div> <div class="grid-row flex-wrap margin-top-1"> <input type="submit" name="commit" value="Sign Up" class="usa-button usa-button--outline usa-button--inverse"> </div> </div> </form> </div> <div class="grid-container margin-y-4"> </div> </div> </div> </section> </div> <div data-elastic-exclude>  <footer class="nist-footer padding-bottom-4"> <div class="grid-container nist-footer__info"> <div class="grid-row"> <div class="tablet:grid-col-6"> <div class="nist-footer__logo"> <a href="/web/20231003083231/https://www.nist.gov/" title="National Institute of Standards and Technology" rel="home"> <img class="nist-footer__logo-img" src="/web/20231003083231im_/https://www.nist.gov/libraries/nist-component-library/dist/img/logo/NIST-Logo-Brand-White.svg" alt="National Institute of Standards and Technology logo" width="300px" height="42px"/> </a> </div> <div class="nist-footer__contact"> <h3 class="nist-footer__contact-heading">HEADQUARTERS</h3> <address> 100 Bureau Drive<br> Gaithersburg, MD 20899<br> <a href="https://web.archive.org/web/20231003083231/tel:301-975-2000">301-975-2000</a> </address> <p> <a href="https://web.archive.org/web/20231003083231/mailto:do-webmaster@nist.gov">Webmaster</a> | <a href="https://web.archive.org/web/20231003083231/https://www.nist.gov/about-nist/contact-us">Contact Us</a> | <a href="https://web.archive.org/web/20231003083231/https://www.nist.gov/visit">Our Other Offices</a> </p> </div> </div> <div class="tablet:grid-col-6"> <div class="nist-footer__social-links"> <a class="nist-social nist-social--twitter-white" href="https://web.archive.org/web/20231003083231/https://twitter.com/NIST"> <span>Twitter</span> </a> <a class="nist-social nist-social--facebook-white" href="https://web.archive.org/web/20231003083231/https://www.facebook.com/NIST"> <span>Facebook</span> </a> <a class="nist-social nist-social--linkedin-white" href="https://web.archive.org/web/20231003083231/https://www.linkedin.com/company/nist"> <span>LinkedIn</span> </a> <a class="nist-social nist-social--instagram-white" href="https://web.archive.org/web/20231003083231/https://www.instagram.com/nist/"> <span>Instagram</span> </a> <a class="nist-social nist-social--youtube-white" href="https://web.archive.org/web/20231003083231/https://www.youtube.com/NIST"> <span>YouTube</span> </a> <a class="nist-social nist-social--giphy-white" href="https://web.archive.org/web/20231003083231/https://giphy.com/nist"> <span>Giphy</span> </a> <a class="nist-social nist-social--rss-white" href="https://web.archive.org/web/20231003083231/https://www.nist.gov/news-events/nist-rss-feeds"> <span>RSS Feed</span> </a> <a class="nist-social nist-social--envelope-white" href="https://web.archive.org/web/20231003083231/https://public.govdelivery.com/accounts/USNIST/subscriber/new"> <span>Mailing List</span> </a> </div> <div class="nist-footer__feedback"> How are we doing? <a class="usa-button" rel="nofollow" href="/web/20231003083231/https://www.nist.gov/form/nist-gov-feedback?destination=/chemistry" title="Provide feedback">Feedback</a> </div> </div> </div> </div> <div class="grid-container"> <div class="nist-footer__nav" role="navigation"> <ul> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231003083231/https://www.nist.gov/privacy-policy">Site Privacy</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231003083231/https://www.nist.gov/oism/accessibility">Accessibility</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231003083231/https://www.nist.gov/privacy">Privacy Program</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231003083231/https://www.nist.gov/oism/copyrights">Copyrights</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231003083231/https://www.commerce.gov/vulnerability-disclosure-policy">Vulnerability Disclosure</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231003083231/https://www.nist.gov/no-fear-act-policy">No Fear Act Policy</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231003083231/https://www.nist.gov/office-director/freedom-information-act">FOIA</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231003083231/https://www.nist.gov/environmental-policy-statement">Environmental Policy</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231003083231/https://www.nist.gov/summary-report-scientific-integrity">Scientific Integrity</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231003083231/https://www.nist.gov/nist-information-quality-standards">Information Quality Standards</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231003083231/https://www.commerce.gov/">Commerce.gov</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231003083231/http://www.science.gov/">Science.gov</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231003083231/http://www.usa.gov/">USA.gov</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231003083231/https://vote.gov/">Vote.gov</a> </li> </ul> </div> </div> </footer>  </div> </div> <script type="application/json" data-drupal-selector="drupal-settings-json">{"path":{"baseUrl":"\/","scriptPath":null,"pathPrefix":"","currentPath":"node\/1079101","currentPathIsAdmin":false,"isFront":false,"currentLanguage":"en"},"pluralDelimiter":"\u0003","suppressDeprecationErrors":true,"back_to_top":{"back_to_top_button_trigger":100,"back_to_top_prevent_on_mobile":false,"back_to_top_prevent_in_admin":true,"back_to_top_button_type":"image","back_to_top_button_text":"Back to top"},"google_analytics":{"account":"G-HEQ0YF2VYL","trackOutbound":true,"trackMailto":true,"trackTel":true,"trackDownload":true,"trackDownloadExtensions":"7z|aac|arc|arj|asf|asx|avi|bin|bsh|c|csv|doc(x|m)?|dot(x|m)?|dw(fx|g|gd)|dxf|eps|epub|exe|f(90)|flv|gif|gz|gzip|hqx|jar|jpe?g|js|m1v|mp(2|3|4|e?g)|mobi|mov(ie)?|msi|msp|pdf|phps|pl|png|ppt(x|m)?|pot(x|m)?|pps(x|m)?|ppam|sld(x|m)?|thmx|qtm?|ra(m|r)?|rfa|rtf|rvt|sch|sea|sit|swf|tar|tgz|tif|txt|txz|wav|wma|wmv|wpd|wrl|xls(x|m|b)?|xlt(x|m)|xlam|xml|xsd|z|zip"},"nist_search":{"clickTracking":"search-report-click","isDebug":false,"clickTrackEnabled":true,"message":"NIST Search in debug mode. Check the browsers network inspector for Click Track reporting results..."},"data":{"extlink":{"extTarget":false,"extTargetNoOverride":false,"extNofollow":false,"extNoreferrer":false,"extFollowNoOverride":false,"extClass":"ext","extLabel":"(link is external)","extImgClass":false,"extSubdomains":true,"extExclude":"\\.gov\\\/|\\.mil\\\/|\\manufacturingusa\\.com\\\/","extInclude":"","extCssExclude":"","extCssExplicit":"","extAlert":true,"extAlertText":"Thank you for visiting NIST. We hope your visit was informative. We have provided a link to this site because it has information that may be of interest to our users. NIST does not necessarily endorse the views expressed or the facts presented on this site. Further, NIST does not endorse any commercial products that may be advertised or available on this site. Click OK to be directed to your link.","mailtoClass":"0","mailtoLabel":"(link sends email)","extUseFontAwesome":false,"extIconPlacement":"append","extFaLinkClasses":"fa fa-external-link","extFaMailtoClasses":"fa fa-envelope-o","whitelistedDomains":[]}},"user":{"uid":0,"permissionsHash":"582eea317b4636ab5a0dffc8c6a006df3d6901ea5610498a0bbefc925ea1da0f"}}</script> <script src="/web/20231003083231js_/https://www.nist.gov/sites/default/files/js/js_vUzvThvSSVoHTSCkBCQkydhdsfaK1XKjKqS_Be_Zm8E.js"></script> <script src="https://web.archive.org/web/20231003083231js_/https://siteimproveanalytics.com/js/siteanalyze_6017546.js" async></script> <script src="/web/20231003083231js_/https://www.nist.gov/sites/default/files/js/js_uqh7FX-i8Xg681oc_jxRphyTScuBg4ZoovDrgaxRXxc.js"></script> <script type="text/javascript">window.NREUM||(NREUM={});NREUM.info={"beacon":"gov-bam.nr-data.net","licenseKey":"37b7ccb661","applicationID":"1089704227","transactionName":"YFxUN0sADEdYVkBaClkWdwBNCA1aFkVVVABoWlcAUQQ=","queueTime":5,"applicationTime":50,"atts":"TBtXQQMaH0k=","errorBeacon":"gov-bam.nr-data.net","agent":""}</script></body> </html>

CINXE.COM

Chemistry | NIST