ionizationios10
ios10.0.3 时间:2021-01-29 阅读:(
)
1GasChromatography(GC;GLC;GSC)"BasicGasChromatography"byMcNair,Wiley,1997"ModernPractiseinGC"byGrob,pp.
900"GasChromatography"byWillett,pp.
250(Wiley)MartinandSynge1941idea;1952instrument1969NobelprizeManufacturersPerkinElmer,HewlettPackard,Shimadsu,Phillips,CarloErba,Varian,etcpriceinexpensive;manyperlaboratorySeparationtechnique—puren'simplepartitioningbetweentwophases2SchematicGCapparatusLiquidsampleofca.
0.
1mlvolumeinjectedviaasyringeintoheatedinjectorportwhereitisrapidlyvolatilisedandsweptbyastreamofflowing(carrier)gasthruacolumn&outviaadetector.
3Impuritiesinstyrene60mInnowax,2ml/minHe,1mlsplit80:1,80C(9min),5C/minto150C4SchematicgaschromatographCarriergas(highpurity,unreactive,cheap):N2,He,H2Flowcontrolconstant,reproducibleflowrateInjectionport(sampleinlet,microlitresyringe)Oven—thermostattedatconstantTorlinearrateColumnDetectorDataprocessingretentiontime(volume)peakarearecorder,integrator,microprocessor,computer,etc5Powerfulanalyticaltool—whyVerylargeseparatingpowerpara(138.
4°C),ortho(144.
4°C)&meta(139.
1°C)xyleneHighspeedofanalysisnosamplepre-treatmentusuallyQuantitativeanalysisexcellentHighsensitivity58ppmofphenylacetylene(#11)instyrenesampleQualitativeanalysistheAchillesheel!
Justbecausepeakat18minislabelleda-methylstyreneSimpletouseandoperateunskilled,automatic,lowcost6QualitativeanalysisIdentificationbasedonretentiontimes(volumes)NotconclusiveevenbycomparingtwoormoredifferentcolumnsIfanalytesknownthenreasonablesuppositionUnambiguousGC+MSorGC+IRMixtureofunknownalcoholsknownsn-amyl7Quantitativeanalysis5.
00mlofasolncontaininganinternalstandard,S,ofconcentration100mg/mlwereaddedtoasolnofunknown,X.
Chromatographyofthemixturegaveanarearatioof(AX/AS)=0.
81±0.
01.
Calibrationofknownweightratiomixesgave:weightratio,W=(WX/WS)0.
200.
400.
80arearatio,A=(AX/AS)0.
230.
460.
91CalculateweightofXinunknown.
Byleast-squares:A=1.
132W+0.
005soifA=0.
81thenW=0.
711butWS=500mg\WX=356mg8Detectors—keycomponentsFlameionizationfamilytheparentFID—workhorse,quasi-universal,reliableflamephotometricFPD—#6sulphur/phosphorusdetectoralkaliflameAFIDornitrogen/phosphorusNPDorTIDElectroncaptureECD—#5halothaneinbloodanalysisveryhighsensitivity,veryselectiveThermalconductivityTCDorHWDorkatharometerrobust,universal,lowsensitivityMassspectrometerMSD—expensivebutworthitexcellentforidentification9Flameionisationdetector(s)FID(basicdesign)mixH2andcarrier,burnincleandust-freeaircollectionsformedcurrentelutingcpdsAFID(N/Psensitive)surroundjetbyalkalisaltsurfacecatalysedreactionsFPD(collectphotonsemitted)Sulphurmode394nmPhosphorusmode526nm10FlameionizationdetectorMDQ—5picograms/secondResponse—quasi-universalLinearity—excellent(over106)Stability—flowandtemperatureinsensitiveTemperaturelimit—400CCarriergas—Nitrogen,heliumorhydrogenSummaryRuggednon-responsivetowaterandair("inorganics")destructiveandverywidelyused11FlamephotometricdetectorMDQ—1nanogramS(394nm);0.
1ngP(526nm)Response—effectivelyonlySandPcompoundsLinearity—moderate(104)Stability—goodTemperaturelimit—400CCarrier—nitrogenSummaryveryselectiveflameneedscleanhydrogen/airsupplyexpensivebutinvaluableforpesticideandairpollutionwork12FlamephotometricdetectorSulphurmode;394nmlargesolventpeaksmallhydrocarbonpeak(pentadecane)for4,000ngdodecanethiol(IS)20ngmethylparathion20ngPhosphorusmode;526nmtinysolventpeaktributylphosphate(IS)20ngmethylparathion20ngSamesampleinbothcases13HotWireDetector(TCD)Tungsten-rheniumfilamentsCurrentof0.
3Aat16VTemperatureoffilament350CbutdependsonthermalconductivityofgasflowingoverhotwireResistanceofwirechangesasTchangesPre&postcolumndetection14ThermalconductivitydetectorMDQ—10nanograms(about50ppm)Response—universal(allexceptthecarrier)Linearity—moderate(104)Stability—flowandtemperaturesensitiveCarrier—hydrogenorheliumTemperaturelimit—400CSummarynon-destructiveandsimpletooperate(portable)moderatestabilityandsensitivyusedforfixedgasanalysis,eg,H2,N2,O2,CO2,Ar,etc15ElectroncapturedetectorRadioactivesourceemitsb-particles(fastelectrons)whichareconvertedintoslowelectronsbycollisionwithN2carriergasThesearecapturedbymoleculestoformaslowermovinganionsReductionincurrentascompoundflowsthroughdetector16ECD:organohalogenpesticidesColumnDB-210+15mx0.
53mmid;film1.
0mmHecarrier;100°-220°Cat3°C/min.
600pgeach2-lindane;4-aldrin;9-dieldrin;13-DDT17ElectroncapturedetectorMDQ—veryhighsensitivity(picogramrange)Response—veryselective(halogenatedcompoundsonly)Linearity—Poor(500to104)Stability—fairTemperaturelimit—220C(3H)or350C(Ni)Carrier—nitrogenorargon+10%methaneSummaryeasilycontaminated,carriermustbedrynon-destructiverequireslicenseforradioactivesource18ECD;biphenylsat30ppbeachMDQ:10fglindanein2mlinjection19ThecolumnTwokindscapillary(WCOT:0.
2to5mmfilmthickness,PLOT)0.
3mmid50m300,000plates0.
01ml2ml/minpacked3mmid2m3,000plates10ml40ml/minLiquidphaselowvapourpressureoveroperatingrange&thermallystablechemicallyinerttosolutesgoodsolventforsolutesusedandlowviscosityTemperatureisothermalprogrammed(linear,reproducible)20Packedcolumns(SS,glass)or"od;coiled,U-shapedSolidsupportuniformporediameter(10mmorless)largeinertsurfacearea(AW,treatedwithDMCS)regularlyshaped,uniformlysized(meshnos.
)egChromosorbW/AW/DMCS100-120meshPreparation(5%XonY):slurry5gliquidphaseXwith100gsolidsupportYinsmallquantityofsuitablesolventRotovapoffsolvent,packcolumnLeaveovernightathighestsafetemperatureinovenwithflowofcarrier21EffectofcolumntemperatureIncreasingthecolumntemperaturereducesretentiontimesbiggesteffectonlongesttimesConflict:analysistimeversusresolutionTemperatureprogrammingsidestepsprobleminitial,final,rateofclimbandtimings22SoluteclassesBasedonH-bondingcapabilityWeakbondIPolyalcohols,aminoalcohols,etcIIAlcoholsIIIEthers,ketonesIVAromatics,olefins,halocarbonsVSaturatedhydrocarbons23"Liquid"phase—theheartoftheGC'Polarity'Squalane—thestandardphasewithzeropolaritySiliconegumSE30/OV-1100-300C220Dexsil30050-400C470Di-nonylphthalate0-150C790OV-210silicone20-275C1500Polyethyleneglycol(CarboWax)60-225C2300OV-275silicone100-275C420024RTX-200(trifluoropropylmethylpolysiloxane)25Stabilwax(CarbowaxPEG20M)26SpecialisedapplicationsPyrolysisbrakeliningdustHeadspaceanalysisblackpeppercornsorcolacanMulticolumntechniquesdualback-flushingheart-cuttingHyphenatedGC+MSGC/FTIRPreparativeGCPyrogram27Headspaceanalysisof0.
1%cpdinwater28Multi-columntechniquesBackflushingtoventspeedingupanalysisofA,BbynotbotheringwithC,DHeart-cuttinganalyseforBinthepresenceoflargeamountsofinterferingADualcolumnfordifficultseparations1stcolumncanseparateA&BbutnotC&D;2ndcolvice-versa
由于行业需求和自媒体的倾向问题,对于我们个人站长建站的方向还是有一些需要改变的。传统的个人网站建站内容方向可能会因为自媒体的分流导致个人网站很多行业不再成为流量的主导。于是我们很多个人网站都在想办法进行重新更换行业,包括前几天也有和网友在考虑是不是换个其他行业做做。这不有重新注册域名重新更换。鉴于快速上手的考虑还是采用香港服务器,这不腾讯云和阿里云早已不是新账户,考虑到新注册UCLOUD账户还算比...
傲游主机怎么样?傲游主机是一家成立于2010年的老牌国外VPS服务商,在澳大利亚及美国均注册公司,是由在澳洲留学的害羞哥、主机论坛知名版主组长等大佬创建,拥有多家海外直连线路机房资源,提供基于VPS主机和独立服务器租用等,其中VPS基于KVM或者XEN架构,可选机房包括中国香港、美国洛杉矶、韩国、日本、德国、荷兰等,均为CN2或者国内直连优秀线路。傲游主机提供8折优惠码:haixiuge,适用于全...
萤光云怎么样?萤光云是一家国人云厂商,总部位于福建福州。其成立于2002年,主打高防云服务器产品,主要提供福州、北京、上海BGP和香港CN2节点。萤光云的高防云服务器自带50G防御,适合高防建站、游戏高防等业务。目前萤光云推出北京云服务器优惠活动,机房为北京BGP机房,购买北京云服务器可享受6.5折优惠+51元代金券(折扣和代金券可叠加使用)。活动期间还支持申请免费试用,需提交工单开通免费试用体验...
ios10.0.3为你推荐
FDCphp支持ipad支持ipadiphone连不上wifi苹果手机“无法加入网络”怎么办canvas2html5创建两个canvas后,怎么回到第一个canvas联通版iphone4s怎么区分iphone4s电信版和联通版重庆电信宽带测速重庆电信光纤宽带网络,内外网络和电脑等设备都没发生变化的情况下,办理了从20M提速到100M业务。迅雷快鸟迅雷快鸟这种强盗软件不违规吗?win7关闭135端口win7系统怎么关闭135端口?网上很多方法都不好用!google统计怎样获得google ga 统计代码
vir 主机测评网 softlayer godaddy主机 韩国空间 腾讯云数据库 idc评测网 双11抢红包攻略 win8.1企业版升级win10 免费ftp空间申请 台湾谷歌地址 免费高速空间 微软服务器操作系统 七夕快乐英语 台湾google 便宜空间 海外空间 ebay注册 中国linux 阿里云邮箱登陆 更多