Reagente chimico

Definitionofchemicalreagents

Chemicalreagentshavebeenwidelyusedinindustry,agriculture,medicalandhealth,lifesciences,inspectionandquarantine,environmentalprotection,energydevelopment,nationaldefenseandmilitaryindustry,Scientificresearchandallwalksoflifeinthenationaleconomy,butwhatisa"chemicalreagent",whatcontentitcontains,anditisstillaverydifficultthingtogiveitanaccuratedefinition.Earlychemicalreagentsonlyreferto"purechemicalsusedtodeterminethecompositionorcompositionofsubstancesinchemicalanalysisandchemicaltests."Itwaslaterexpandedto"chemicalsusedtoachievechemicalreactions",andthechemicalsreferredtoby"chemicalreagents"havelonggonebeyondthiscategory.Somepeoplethinkthat"chemicalsusedinscientificexperiments"canbecalled"chemicalreagents."Amorecomprehensivedefinitionofchemicalreagentscanbe:compoundsorelementsofvariouspuritylevelsusedinchemicaltests,chemicalanalysis,chemicalresearchandothertests.

Currentnationalstandards

GB/T14305-1993chemicalreagentcyclohexane

GB15346-1994chemicalreagentpackagingandmarking

GB/T15347-1994chemicalreagentascorbicacid

GB/T15895-1995chemicalreagent1,2-dichloroethane

GB/T15896-1995chemicalreagentformicacid

GB/T15897-1995chemicalreagentcalciumcarbonate

GB/T15898-1995chemicalreagentcobaltnitratehexahydrate(cobaltnitrate)

GB/T15899-1995Chemicalreagentmanganesesulfatemonohydrate(manganesesulfate)

GB/T15901-1995Chemicalreagentcopperchloridedihydrate(copperchloride)

GB/T629-1997chemicalreagentsodiumhydroxide

GB/T1264-1997chemicalreagentsodiumfluoride

GB/T640-1997chemicalreagentsodiumbicarbonate

GB/T671-1998chemicalreagentmagnesiumsulfate

GB/T689-1998chemicalreagentpyridine

GB/T1401-1998chemicalreagentdisodiumedetate

GB/T1268-1998chemicalreagentsodiumthiocyanate

GB/T642-1999chemicalreagentpotassiumdichromate

GB/T649-1999chemicalreagentPotassiumbromide

GB/T684-1999chemicalreagenttoluene

GB/T1276-1999chemicalreagentammoniumfluoride

GB/T2305-2000Chemicalreagentphosphoruspentoxide

GB/T6684-2002chemicalreagent30% hydrogenperoxide

GB/T678-2002chemicalreagentethanol(absoluteethanol)

GB/T12591-2002chemicalreagentether

GB/T682-2002chemicalreagentchloroform

GB/T679-2002chemicalreagentethanol(95%)

PreparationofGB/T601-2002chemicalreagentstandardtitrationsolution

PreparationofpreparationsandproductsusedinGB/T603-2002chemicalreagenttestmethod

GB/T602-2002PreparationofStandardSolutionforImpurityDeterminationofChemicalReagents

GB/T652-2003ChemicalReagentBariumChloride

GB/T1265-2003chemicalreagentsodiumbromide

GB/T606-2003chemicalreagentwaterdeterminationgeneralmethodKarlFischermethod

GB/T674-2003chemicalreagentPowderedcopperoxide

GB/T656-2003chemicalreagentammoniumdichromate

GB/T16493-1996chemicalreagenttrisodiumcitratedihydrate(trisodiumcitrate)

GB/T16494-1996chemicalreagentxylene

GB/T16496-1996chemicalreagentpotassiumsulfate

GB/T16983-1997chemicalreagenttwoMethylchloride

GB/T17521-1998ChemicalreagentN,N-dimethylformamide

GB/T615-2006Generalmethodforthedeterminationofboilingrangeofchemicalreagent

GB/T9721-2006GeneralRulesofChemicalReagentMolecularAbsorptionSpectrophotometry(UVandVisibleLightPart)

GB/T1263-2006ChemicalReagentDisodiumHydrogenPhosphateDodecahydrate(DisodiumHydrogenPhosphate))

GB/T1266-2006chemicalreagentsodiumchloride

GB/T617-2006generalmethodforthedeterminationofmeltingpointrangeofchemicalreagent

GB/T9722-2006GeneralPrinciplesofGasChromatographyforChemicalReagents

GB/T605-2006GeneralMethodforChromaticityDeterminationofChemicalReagents

GB/T614-2006GeneralMethodforDeterminationofRefractiveIndexofChemicalReagents

GB/T622-2006ChemicalReagentHydrochloricAcid

GB/T626-2006ChemicalReagentNitricAcid

GB/T616-2006GeneralMethodforBoilingPointDeterminationofChemicalReagents

GB/T9739-2006Chemicalreagentirondeterminationgeneralmethod

GB/T683-2006Chemicalreagentmethanol

GB/T611-2006ChemicalreagentdensityGeneralmethodofdetermination

GB/T618-2006Generalmethodfordeterminationofcrystallizationpointofchemicalreagents

GB/T673-2006Chemicalreagentofarsenictrioxide

GB/T609-2006Generalmethodfordeterminationoftotalnitrogeninchemicalreagents

GB/T637-2006Chemicalreagentsodiumthiosulfatepentahydrate(sodiumthiosulfate)

GB/T672-2006Chemicalreagentmagnesiumchloridehexahydratum (magnesiumchloride)

GB/T658-2006Chemicalreagentammoniumchloride

GB/T621-1993ChemicalReagentHydrobromicAcid

GB/T9725-2007GeneralRulesforPotentiometricTitrationofChemicalReagents

GB/T9726-2007GeneralRulesforDeterminationofPotassiumPermanganateSubstancesReducedbyChemicalReagents

GB/T9732-2007Generalmethodforthedeterminationofammoniumwithchemicalreagents

GB/T9730-2007Generalmethodforthedeterminationofoxalatewithchemicalreagents

GB/T9724-2007GeneralrulesforthedeterminationofpHvalueofchemicalreagents

GB/T9729-2007Generalmethodforthedeterminationofchlorideinchemicalreagents

GB/T631-2007Ammoniawaterforchemicalreagents

GB/T613-2007Generalmethodfordeterminationofspecificopticalpower(specificopticalrotation)ofchemicalreagents

GB/T638-2007Chemicalreagentstannouschloridedihydrate(Ⅱ)(stannouschloride)

GB/T6685-2007chemicalreagenthydroxylaminechloride(hydroxylaminehydrochloride)

GB/T625-2007chemicalreagentsulfuricacid

GB/T676-2007ChemicalReagentAceticAcid(GlacialAceticAcid)

GB/T9731-2007ChemicalReagentGeneralMethodforDeterminationofSulfurCompounds

GB/T1272-2007ChemicalReagentPotassiumIodide

GB/T9727-2007Generalmethodforthedeterminationofphosphateinchemicalreagents

GB/T10726-2007Generalmethodforthedeterminationofmetalimpuritiesbychemicalreagentsolventextraction-atomicabsorptionspectrometry

GB/T9723-2007GeneralRulesofFlameAtomicAbsorptionSpectrometryforChemicalReagents

GB/T670-2007ChemicalReagentSilverNitrate

GB/T12589-2007ChemicalReagentEthylAcetate

GB/T665-2007ChemicalReagentAnhydrousCopperSulfate(Ⅱ)(CopperSulfate)

GB/T9728-2007GeneralMethodforDeterminationofSulfateinChemicalReagents

GB/T633-1994chemicalreagentsodiumnitrite

GB/T650-1993chemicalreagentpotassiumbromate

GB/T1279-2008chemicalreagentironsulfatedodecahydrate(Ⅲ)Ammonium

GB/T2304-2008chemicalreagentarsenic-freezincparticles

GB/T9734-2008chemicalreagentaluminumdeterminationgeneralmethod

GB/T9855-2008chemicalreagentcitricacidmonohydrate(citricacid)

GB/T696-2008chemicalreagenturea(urea)

GB/T660-1992chemicalreagentammoniumthiocyanate

GB/T1291-2008chemicalreagentpotassiumhydrogenphthalate

GB/T10705-2008Chemicalreagent5-sulfosalicylicaciddihydrate(5-sulfosalicylicacid)

GB/T9854-2008Chemicalreagentoxalicaciddihydratorum(oxalicacid)

GB/T610-2008chemicalreagentgeneralmethodfordeterminationofarsenic

GB/T1273-2008chemicalreagentpotassiumhexacyanoferrate(potassiumferrocyanide)

GB/T9742-2008Generalmethodfordeterminationofsilicateinchemicalreagents

GB/T9741-2008Generalmethodfordeterminationofignitionresiduesinchemicalreagents

GB/T9737-2008GeneralRulesfortheDeterminationofEasilyCarbonizedSubstancesinChemicalReagents

GB/T9740-2008GeneralMethodforDeterminationofEvaporationResiduesinChemicalReagents

GB/T632-2008ChemicalReagentSodiumTetraborateDecahydratorum (tetraborateSodium)

GB/T2306-2008chemicalreagentpotassiumhydroxide

GB/T639-2008chemicalreagentanhydroussodiumcarbonate

GB/T15894-2008Chemicalreagentpetroleumether

GB/T1292-2008Chemicalreagentammoniumacetate

GB/T686-2008Chemicalreagentacetone

GB/T690-2008chemicalreagentbenzene

GB/T1294-2008chemicalreagentL(+)-tartaricacid

GB/T9733-2008chemicalreagentcarbonylcompounddeterminationgeneralmethod

GB/T9735-2008Generalmethodforthedeterminationofheavymetalsinchemicalreagents

GB/T9736-2008Generalmethodforthedeterminationofacidityandalkalinityofchemicalreagents

GB/T9738-2008Generalmethodfordeterminationofwater-insolublematterinchemicalreagents

GB/T15355-2008Chemicalreagentnickelchloridehexahydrate(nickelchloride)

GB/T643-2008ChemicalreagenthighmanganesePotassiumacid

GB/T3914-2008Chemicalreagentanodicstrippingvoltammetrygeneralrules

GB/T12590-2008Chemicalreagentn-butanol

GB/T9853-2008Chemicalreagentanhydroussodiumsulfate

GB/T667-1995Chemicalreagentzincnitratehexahydrate(zincnitrate)

GB/T669-1994ChemistryReagentstrontiumnitrate

GB/T685-1993chemicalreagentformaldehydesolution

GB/T691-1994chemicalreagentaniline

GB/T693-1996chemistryReagentsodiumacetatetrihydrate(sodiumacetate)

GB/T694-1995chemicalreagentanhydroussodiumacetate

GB/T11547-2008plasticliquidchemicalreagentresistancedetermination

GB/T23942-2009ChemicalReagentGeneralPrinciplesofInductivelyCoupledPlasmaAtomicEmissionSpectrometry

GB/T657-2011ChemicalReagentAmmoniumMolybdateTetrahydrate(AmmoniumMolybdate)

p>

GB/T659-2011chemicalreagentammoniumnitrate

GB/T1281-2010chemicalreagentbromine

GB/T623-2011chemicalreagentperchloricacid

GB/T644-2010chemicalreagentpotassiumhexacyanoferrate(Ⅲ)potassiumferricyanide(potassiumferricyanide)

GB/T661-2010chemicalreagentironsulfatehexahydrate(Ⅱ)Ammonium

GB/T646-2011chemicalreagentpotassiumchloride

GB/T664-2010chemicalreagentferrumsulfateheptahydrate(ferroussulfate)

GB/T620-2011chemicalreagenthydrofluoricacid

GB/T688-2011chemicalreagentcarbontetrachloride

GB/T647-2011Chemicalreagentpotassiumnitrate

GB/T636-2011Chemicalreagentsodiumnitrate

GB/T677-2011Chemicalreagentaceticanhydride

GB/T666-2011Chemicalreagentzincsulfateheptahydrate(zincsulfate)

GB/T1271-2011Chemicalreagentpotassiumfluoridedihydrate(potassiumfluoride)

GB/T641-2011Chemicalreagentpotassiumperoxodisulfate(potassiumpersulfate)

GB/T655-2011chemicalreagentammoniumpersulfate

GB/T15354-2010chemicalreagenttributylphosphate

GB/T645-2011chemicalreagentpotassiumchlorate

GB/T653-2010chemicalreagentbariumnitrate

GB/T628-2011chemicalreagentboricacid

GB/T687-2011chemicalreagentglycerol

GB/T675-2010chemicalreagentiodine

GB/T651-2010chemicalreagentpotassiumiodate

GB/T1274-2011Chemicalreagentpotassiumdihydrogenphosphate

GB/T648-2011Chemicalreagentpotassiumthiocyanate

GB/T1288-2011Chemicalreagentpotassiumsodiumtartratetetrahydrate(potassiumsodiumtartrate)

GB/T1267-2011chemicalreagentsodiumdihydrogenphosphatedihydrate(sodiumdihydrogenphosphate)

GB/T654-2010chemicalreagentbariumcarbonate

GB/T1270-1996chemicalreagentcobaltchloridehexahydrate(cobaltchloride)

GB/T1278-1994chemicalreagentammoniumbifluoride

GB/T1282-1996Chemicalreagentphosphoricacid

GB/T1285-1994Chemicalreagentcadmiumchloride

GB/T1289-1994Chemicalreagentsodiumoxalate

GB/T1396-1993chemicalreagentammoniumsulfate

GB/T1397-1995chemicalreagentpotassiumcarbonate

GB/T1400-1993chemicalreagenthexamethylenetetramine

GB/T13353-1992Determinationoftheresistanceofadhesivestochemicalreagents.MetalsandmetalsTitle:

Contentus-basedtitle

Standards substantia, standardsolutions, vexillum incorruptio, regulae substantialis, vexillum specimen, regula saxum, indexreagentum,referentiae substantia, tribunal reagentia, normae scopos, normas oeconomiae, instrumenta analytica, principalia, prima classium, signatorreagentum, substancia, tribunal reagentia, normae scopos, normas oeconomiae, instrumenta analytica, alta- menta, prima classiaria, signatorreagentum, substantialis chromatographicpuritas, electronic puritas, chalybeus sample, cautum specimen, specimen coalstandardum, specimen castitatis, etc...

Appellationbasedonusage

Chemicalreagentes, generales, analyticas, diagnostica, doctrinas, experimentales, segregationes, instrumenta, buffersolutions, indicatorreagentes, maculas biologicas, photosensitivas materiales, syntheticas, medias, chemicalrawmaterias, segregationes, qualitates.

Source-basedtitles

Imported Edition

Custom-basedtitles

Chemicals, Finechemicals, medicamenta

Appellationsbasedonproperties

Inorganicreagents, organicreagents, isotopesandlabeledcompounds, biochemicalreagents, aminoacidtheandtheagtheagtivativativativates, proteinsandpeptides, nucleotidesandtheacharides, Monosaccharidesandpolmedsaccharides, MonosacchorzesAdia, ChromatographicMedia, ElectrophoresMedia, Biologhbufers ..., ElectrophoresMedia, ChromatographicMedia ..., ElectrophoresMedia, BiologsAgsMedia ...

Classificationbasis

Thecategoriesofchemicalreagentsarebasicallyclassifiedaccordingtotheirpurposeorsubjectmatter.Manynewcategorieshavebeenadded.Germany'sE.Merckcompanyisdividedinto20categoriesand88sub-categories.AmericanBaker(J.T.Baker)companyhas75majorcategoriesand124sub-categories.Withthedevelopmentofscienceandtechnology,thevarietyofchemicalreagentsisbecomingmoreandmorediverse,andthetrendofcategorydivisionisgettingmoreandmoredetailed,andithasreachedtheserializationandmatchingofvarieties.

QualityIndex

Thequalitylevelsofchemicalreagentsarecomplexandtherearemanyvarieties,whichareparticularlyconfusing.Thegeneralconventionalvarieties(class1reagents)areessentialvarieties,andthereare225species,whicharebasicallycomplementaryproducedinmycountry'schemicalreagentbasesinBeijing,Tianjin,Shanghai,Xi'an,Chengdu,Guangzhou,andShenyang.TypeIIreagentsareusedinalmostallfields,andtheyarealsonecessaryvarietiesformanufacturers.Thereareabout1800-2000varieties.Suchreagentsareinlargedemandandwidelyused.Thereareabout3000-6000varietiesofthethreetypesofreagents,andmostoftheirapplicationfieldsarerelatedtothenationaleconomyandpeople'slivelihood,suchaschemical,metallurgy,electricpower,food,medicineandhealthandotherindustriesthatarespecificallyusedinindustryreagents.

Inmycountry,thereare225kindsofchemicalreagentsrepresentedbythreegrades:premiumgrade,analyticalgrade,andchemicalgrade,accordingtothenationalstandardsofthePeople’sRepublicofChinaandthestandardsissuedbytheformerMinistryofChemicalIndustry.These225kindsofchemicalreagents,intheformofstandards,stipulatethebasisofthecontentofchemicalreagentsinourcountry.Thecontentdeterminationofotherchemicalsisbasedonthis,andthecontentisdeterminedbymeasurement.Therefore,thequalityofthesechemicalreagentsisveryimportant.Atthesametime,these225chemicalreagentshavebecomebasicvarietiesduetotheirextremelywideuse.These225specieshavebeenmarkedinthecatalogofchemicalreagents.Inaddition,therearespecialreagents,theproductionvolumeisverysmall,almoston-demandproduction,thequantityisgenerallydesignatedbytheuser.

Commonqualitylevels

Excellentgradepure(GR,greenlabel):highcontentofmaincomponents,highpurity,suitableforpreciseanalysisandresearchwork,andsomecanbeusedasbenchmarkssubstance.

Analyticalpurity(AR,redlabel):highcontentofmaincomponents,highpurity,lowinterferenceimpurities,suitableforindustrialanalysisandchemicalexperiments.EquivalenttoforeignACSlevel(AmericanChemicalSocietystandard)

Chemicalpurity(CP,bluelabel):highcontentofmaincomponents,highpurity,presenceofinterferingimpurities,suitableforchemicalexperimentsandsyntheticpreparation.

Experimentalpure(LR,yellowlabel):highcontentofmaincomponents,poorpurity,nochoiceofimpuritycontent,onlysuitableforgeneralchemicalexperimentsandsyntheticpreparation.

Indicises et maculas (IDorSR, purpuralabel): postulat uniquesensititatem.

Designatedlevel(ZD):Chemicalreagentscustomizedforspecificusersinaccordancewiththequalitycontrolindicatorsrequiredbyusers.

Electronicpure(MOS):suitablefortheproductionofelectronicproducts,withextremelylowelectricalimpuritycontent.

Aequivalentes(3N,4N,5N): thema componentcontentisrespectively 99.9%,99.99%,99.999%ormore.

Spectralpurity: thepurityofthemaincomponentsis99.99%

Leveldescription:

Superiorgradepure-GR

MicroorganismUse—FMB

AnalysisPure-AR

Industriae-TECH

ChemicalPure—CP

Nulla—PRACT

Experimentallevel-LR

Forsynthesis-FS^

Biochemicalgrade-BC

Indicis—IND

HighperformanceLiquidchromatography—HPLC

Gaschromatography—GC

Biologicalstaining-BS

Liquidchromatography-LC

Baselinelevel-PT'

ChromatographyUse—FCP

AtomicAbsorption—ASS

Thilayerchromatography—TLC *

Infraredabsorption—IR

SpectrumPure—SP

NuclearMagneticResonance—NMR

SpectroscopyPure-UV

Fluorescenceanalysis—FIA

Synthesis-SYN

Inorganicanalyticalreagentsarecommonlyusedinorganicchemicalsforchemicalanalysis.Itspurityishigherthanthatofindustrialproducts,withlessimpurities.

Organicreagentsforinorganicanalysisarespecialorganiccompoundssuchasprecipitationagents,extractants,chelatingagentsandindicatorsforthedetermination,separationandenrichmentofelementsintheanalysisofinorganicsubstances,Ratherthangeneralsolvents,organicacidsandorganicbases.Theseorganicreagentsmusthavegoodsensitivityandselectivity.Withthedevelopmentofanalyticalchemistryandchemicalindustry,suchreagentswithbettersensitivityandselectivitywillbedeveloped,suchasthosethathavecomplexingabilityforsomemetals(suchasalkalimetals,alkalineearthmetals)andammoniumionssince1967.ThisisthecasewithCrownethercompounds.

Primarystandardsarecompoundswithhighpurity,lessimpurities,goodstabilityandconstantchemicalcomposition.Inthereferencereagents,thereareclassificationssuchasvolumetricanalysis,pHmeasurement,andcalorificvaluemeasurement.Eachcategoryisdividedintothefirstbenchmarkandtheworkingbenchmark.AllthefirstbenchmarksmustbeverifiedbytheNationalAcademyofMetrology,andtheproductionunitusesthefirstbenchmarkasthemeasurementstandardforworkbenchmarkproducts.Thebenchmarkreagentsforcommercialoperationsmainlyrefertothevolumetricanalysisworkbenchmarksinthevolumetricanalysiscategory[contentrangeis99.95%to100.05%(weighttitration)].Generallyusedtocalibratethetitrant.

Standardsubstanceisachemicalsubstanceusedforcomparisoninchemicalanalysisandinstrumentanalysis,orachemicalusedtocalibrateaninstrument.Itschemicalcomposition,content,physicalandchemicalpropertiesandimpuritiesmustbeknown,andmeettheregulationsorberecognized.

ReagentMicro-analytico-reagenti (Micro-analytico-reagente) apta est ad determinationem substantiarum, quantitatis permissae quantitatem constantis (ponderis circa 1~15mg, voluminis circiter 0.01~2ml) Reagentis formicroanalysis.

Organicanalyticalstandardsarechemicalreagentsusedforcomparisonwhendeterminingthecompositionandstructureoforganiccompounds.Itscompositionmustbeaccuratelyknown.Itcanalsobeusedformicroanalysis.

Pesticideanalyticalstandards(Pesticideanalyticalstandards)aresuitableforuseingaschromatographytoanalyzepesticidesordeterminepesticideresiduesascomparisonitems.Itscontentisrequiredtobeprecise.Therearesolutionspreparedfromatraceamountofasinglepesticide,andtherearealsomixedsolutionspreparedfrommultiplepesticides.

Refractiveindexliquid(Refractiveindexliquid)isahigh-puritystableliquidwithaknownrefractiveindex,usedtodeterminetherefractiveindexofcrystallinesubstancesandminerals.Therefractiveindexismarkedontheoutsideofeachpackage.

Normalsolutionisanaqueoussolutioncontainingonegramequivalentofsoluteinoneliterofsolution,thatis,asolutionwithaconcentrationof1N.IndicisIndicis(Indicis)isasubstancethatcanchangeitscolorundertheinfluenceofthepresenceofcertainsubstances.Itismainlyusedtoindicatetheendpointoftitrationinvolumetricanalysis.Generallycanbedividedintoacid-baseindicator,redoxindicator,adsorptionindicatorandsoon.Inadditiontoanalysis,theindicatorcanalsobeusedtotestthepresenceofcertainharmfulandtoxicsubstancesingasesorsolutions.

Testpaperisasmalldrypieceofpapersoakedinanindicatororreagentsolution.Itisusedtotestthepresenceofacertaincompound,elementorioninthesolution.Itisalsousedformedicaldiagnosis.Instrumentalanalyticalreagents

Instrumentalanalyticalreagentsarereagentsusedintheprocessofsampleanalysisusingspecialinstrumentsdesignedaccordingtotheprinciplesofphysics,chemistryorphysicalchemistry.Atomicabsorptionspectroscopystandards

Atomicabsorptionspectroscopystandardsareusedasstandardreagentswhenanalyzingsamplesbyatomicabsorptionspectroscopy.

Forchromatographyreagentsforchromatographyrefertoreagentsandmaterialsusedingaschromatography,liquidchromatography,gas-liquidchromatography,thin-layerchromatography,columnchromatographyandotheranalyticalmethods.Therearestationaryliquids,Supports,solvents,etc.

Forelectronmicroscopy(Forelectronmicroscopy)reagentsarefixatives,embeddingagents,stainsandotherreagentsusedinthefieldsofbiology,medicine,etc.,whenelectronmicroscopesareusedforresearchwork.

SolventforNMRspectroscopy(SolventforNMRspectroscopy)ismainlyadeuteratedsolvent(alsocalledheavyhydrogenreagentordeuteratedreagent),whichisthehydrogenintheorganicsolventstructureisdeuterated(heavyHydrogen)replacedbythesolvent.Innuclearmagneticresonanceanalysis,thedeuteratedsolventmaynotshowpeaks,anditwillnotinterferewiththehydrogenspectrumanalysisofthesample.

Forpolarography(Forpolarography)reagentsrefertothereagentsneededforquantitativeandqualitativeanalysisbypolarography.

SpectralpuritySpectrographyreagentsusuallyrefertoreagentswithhigherpuritythathavebeenanalyzedbyemissionspectroscopy.

Spectrophotometricpurereagentreferstothesolutionusedwhenspectrophotometricanalysisisused.Ithasacertainwavelengthtransmittanceandisusedforqualitativeandquantitativeanalysis.

BiochemicalreagentsBiochemicalreagentsrefertobiologicalmaterialsororganiccompoundsrelatedtolifescienceresearch,aswellasreagentsforclinicaldiagnosisandmedicalresearch.Duetothewiderangeandrapiddevelopmentoflifesciences,thiskindofreagentshasawidevarietyandcomplexproperties.

Otherlevels

Inaddition,itisstilldividedintothefollowingmorethan20levels.

ASSatomicabsorptionspectroscopy,BCbiochemicalreagents,BPBritishPharmacopoeia,BRbiologicalreagents,BSbiologicalstains,CRchemicalreagents,EPultra-pure,FCPchromatography,FMPmicroscopy,FS^synthesis,GCgaschromatography,GRsuperiorgradepurereagent,HPLChighpressureliquidchromatography,IDindicator,IRinfraredabsorptionspectrum,MARtraceanalysisreagent,NMRnuclearmagneticresonancespectroscopy,OASorganicanalysisstandard,PAanalysis,Practpractice,PT'standardReagents,Purissspecialpure,Purumpure,SPspectralpure,Techindustrialuse,TLC *thinlayerchromatography,UPultra-pure,USPUnitedStatesPharmacopoeia,UVultravioletspectrophotometrypure,JXteachingreagent...MIpharmaceuticalgrade,Iindustrialgrade,FFoodgrade,Mcosmeticgrade,Ssolid,Lliquid,Efineproduct,Ccrudeproduct...

Obviously,thegeneralqualitystandardsofthesechemicalreagentsaredividedintotheabove-mentionedqualitylevels,whichisfarfrombeingsatisfied.Researchandproductionneeds.

Validityperiodofchemicalreagents

Chemicalreagentsareaffectedbyexternalfactorssuchastemperature,lightirradiation,airandwaterduringstorage,transportationandsales,andarepronetodeliquescent,Physicalandchemicalchangessuchasmycin,discoloration,polymerization,oxidation,volatilization,sublimationanddecompositionmakeitinvalidandunusable.Therefore,itisnecessarytoadoptreasonablepackaging,appropriatestorageconditionsandtransportationmethodstoensurethatthechemicalreagentsdonotdeteriorateduringstorage,transportationandsales.Somespecialrequirementsforstorageandtransportationshouldbehandledinaccordancewithspecialrequirements.Somechemicalreagentshaveacertainshelflife,sobecarefulwhenusingthem.

Thevalidityperiodofchemicalreagentsvariesgreatlywiththechemicalpropertiesofchemicals.Undernormalcircumstances,chemicallystablesubstanceshavealongershelflifeandsimplerstorageconditions.

StabilityJudgementPrinciples

Forpreliminaryjudgmentofthestabilityofasubstance,thefollowingprinciplescanbefollowed:

Inorganiccompounds,aslongastheyareproperlystored,thepackagingisintact,Canbeusedforalongtime.However,thosesubstancesthatareeasilyoxidizedanddeliquescentcanonlybestoredforashortperiodoftime(1to5years)underdark,cool,anddryconditions,dependingonwhetherthepackagingandstorageconditionscomplywiththeregulations.

Organiclow-molecular-weightcompoundsaregenerallymorevolatile,andthepackaginghasbetterairtightnessandcanbestoredforalongtime.Butitiseasytobeoxidized,decomposedbyheat,easytopolymerize,photosensitivesubstances,etc.

Organicpolymi, praesertim vitales materias, ut vitia, polysaccharides, tela, enzymes, peptides, etc., sunt valde susceptibiles effectibus sofmicroorganismi, temperantia, et lux, et irac- tiam amittunt.

Inprinciple,referencematerials,referencematerialsandhigh-puritymaterialsshouldbestoredinstrictaccordancewiththepreservationregulationstoensurethatthepackagingisintact,avoidbeingaffectedbythechemicalenvironment,andthestoragetimeshouldnotbetoolong.Ingeneral,thereferencesubstancemustbeusedwithinthevalidityperiod.

Thestabilityofmostchemicalsisstillrelativelygood,andthespecificconditionsshouldbedeterminedbyactualuserequirements.Iftheanalysisdataisgenerallyunderstood,ortheanalysisresultsdonothavespecificandaccuraterequirements,suchasgeneralteachingexperiments,generalrequirementscanbemadeforthequalitylevelofchemicalreagents.However,thefactorytestdataisusedtoguideproduction,andthequalityindicatorsofchemicalreagentsmustnotbeambiguous.Asforthechemicalreagentsusedingeneralsyntheticpreparation,inmostcases,theuseofindustrial-gradechemicalreagentsissufficient.However,thesyntheticpreparationofresearch-typeandcertainspecialchemicals,insomecases,hasverystrictrequirementsonthequalityofrawmaterialsandrequiresstrictcontrol.

Inactualuse,peoplearealwaysaccustomedtojudgingtheeffectivenessofchemicalreagentsbythedateofproduction.Infact,itisridiculous.Forexample,inaninstitutionofhigherlearning,wehaveseenwarehousemanagerscleanoutallchemicalreagentsthathavebeenoutofthefactoryformorethan2years,andpreparethemfordestruction.Thereasonisthattheyhaveexpired.Nottomentionthehugewasteoffunds,thedestructionplanofthevariouschemicalhazardousmaterialsaloneisenoughtobeprohibitive.What'smore,commercialcompaniesarenotallowedtobuy,topreventbusinessesfrom"deceivingpeople",thesituationislamentable,andthesituationissad!Later,itissaidthattheselargequantitiesofchemicalreagentswere"deeplydugandburied".

Inshort,theeffectivenessofchemicalreagentsmustfirstbejudgedbasedonthephysicalandchemicalpropertiesofthechemicalreagentsthemselves,andthenthestorageconditionsofthechemicalreagentsshouldbeobservedvisually,andthenwhethertheycanbeusedaccordingtospecificneedsTheconclusion.

Classificationofchemicalreagents

Currentsituationinmycountry

Thereasonableclassificationofchemicalreagentsisfarfrommeetingtheneedsofscientificresearchandproductionduetothedraftingofnationalstandards,anditisseriousIthinderstheproductionofchemicalreagentsinmycountry.Relyingontheexisting227nationalstandardsandindustrystandardsalone,itisdifficulttogivesuchalargenumberofchemicalreagentstoaqualitystandard;itisimpossibleforustogiveallchemicalsanationalqualitystandard,eventomentionWhenitcomestoreagents,thefirstthingpeoplethinkofiswhetheritisanalyticallypureorchemicallypure.Evenwhenpeoplebuy,nomatterwhatthepurposeis,theydon’tbuynon-analyticalreagents.Thisisalsothereasonwhymanyvarietiesthatdonothavenationalstandards,butinexplicablyandbaselesslyendowproductswitharedARlabel.Itisalsobecauseinactualuse,inmanycases,thetrue"analyticalpurity"isnotrequired,andillegalmanufacturersdeliberatelylabeltheindustrialproductswith"analyticalpurity"toconfusethepuritylevel.Althoughqualityaccidentswillnotoccurinmostcases,butHowever,itseriouslyinterfereswiththeproductionanduseofreal"standardmaterialsandanalyticalgrades".

Furthermore,sincethenumberofconventionalchemicalsishuge,butthereareonly225varietiesclassifiedassuperiorgrade,analyticalgradeorchemicalgrade,then,whatelseisnecessary!

Thedifferencebetweenmycountryandtheworld

Internationally,thereisanincreasingtrendtolabelthegradeandpurityofchemicalreagentsaccordingtothemaincontentandphysicalconstantsofchemicals.Itisgenerallybelievedthatwhenthemaincontent,boilingpoint,meltingpoint,density,refractiveindex,andevenultraviolet,infrared,andnuclearmagneticspectraareallknown,thepurityandscopeofapplicationofasubstancecanbecompletelydetermined.Thisisthemaindifferencebetweenthelabelcontentofchemicalreagentsinmycountryandthatofforeignchemicalreagentlabels.

Actually,theso-calledchemicalreagentsarethemedicamentsusedinchemicalexperiments;thatis,thechemicalmedicamentsneededinchemicalexperiments.Theclassificationofchemicalpurityandgradecanbedeterminedaccordingtothequalitystandardsandscopeofapplicationofchemicalagents.

Classification

Accordingtothis,thefirstlevelofchemicalreagentsisdividedintofourcategories:standardreagents,biochemicalreagents,electronicreagents,andexperimentalreagents.

Theclassificationprincipleoflevel1standardnotonlyclarifiesthequalitystandard,butalsotakesintoaccountthescopeofapplicationofthechemicalreagent.

Thelevel2standardisafurtherdivisionbasedonthelevel1classification.Itisafurtherclarificationandlimitationofthelevel1standard.

tothreecriteriaarecomparedwiththeoriginaloldstandard,ormoreaccuratedeterminationofthespecifiedpurposes.

intheLevel1or2isdetermined,aqualityindicatorofthechemicalagent,andthepurposeofthisapplicationthequalityindicatorscanbeappliedalsodetermined.

SoIproposewillbepublishedasananalyticalexaminationofthecriteriaandstandards"standardreagent"qualitystandardsgiveclearnationalstandards.Theremaining"biochemicalreagents,electronicreagents,laboratoryreagents"qualityindicatorscanfollowcorporatestandards,orupdatetheincreasinglytechnologicalrequirementsofdiscretionbythemarket,sothatwechemicalsindustrywillbeabletogetoutoftheoriginal"deadset"ofoldtraditions,developmentboomingup!

standardreagentsBZ:inaccordancewithinternationalnormsandtechnicalrequirementsinordertoidentifyasastandardsubstanceanalysisarbitration.

BiochemicalsSH:preparationbiochemistryandbiochemicalsynthesis.

electrophilesDZ:generallyreferstothechemicalsandmaterialsusedinelectronicinformationindustry,includingintegratedcircuitsanddiscretedeviceschemicals,theprintedcircuitboardsupportingchemicals,chemicalsandsurfacemountdisplaychemicalsandotherdevices.

ReagentsSY:accordingtothe"maincontent"determined"syntheticreagent."Reagentsusedinthesyntheticchemistrylaboratorypreparation,separationandpurification,tomeetthegeneralrequirementsofsynthesisreagents.

tagschemicals "

QualityIndexchemicalsdeterminestheapplicablerangeofchemicalreagents,soIrecommend,shouldannouncetheapprovalofa"chemicalreagentlabel"nationalstandard,thestandardagivenchemicalreagentsandstandardizedqualityindicatorsdescribethesystemwillregulatetheproductionofchemicalreagents,rationaluseofgreatsignificance.

"Chemicalreagentstag" afferens informationem:

registeredtrademark:clearlylabeledregisteredtrademarksofthemanufacturers.

QualityStandard:QualityStandardsimultaneouslydisplaycolorandpinyincodesintwoways.Colordisplayareaasalowerlabelmanufacturerinformationregion;pinyincodes(suchasBZ,SH,DZ,SY)indicatedinaprominentposition.

Seresnameandtype:ProductnameSeresChemicalSocietyin1982published"inorganicchemicalnomenclaturesystems,""organicchemicalsnomenclaturesystem"asthemainbasis,takingintoaccountthelong-termuseofthecommonname,Productname.Andcanbedescribedasaccuratelyaspossiblegivenpatternsordosageofthechemicalagent,forexample:anaqueousalcoholsolution,powder,blocks,sticks,paste,suchasa200meshsizeoreventhelike.

AnglicusName:NametoIUPAC1982Nianpublished"inorganicchemicalnomenclaturesystems,""organicchemicalsnomenclaturesystem"asthemainbasis,takingintoaccountthecommonname,tradename,long-termuse.

CASAccessionNumber:consistit,9digitorum inquarebrackets, hypendividedintotres partes, exempli causa, [58-08-2] CASRegistryNumberiscaffeine.

=molecularformula:MolecularSimplecorrectlywritten,i.e.,theamountofmolecularformulashown,inaccordancewiththe1968publicationoftheinternationalatomicaccuratelycalculatethemolecularweight.TheNaOH=40.10.

content:percentagecontentbymassofthechemicalagentinaccordancewiththemethodspecifiedmolecularnationalstandardsorcorporatestandard,determined.The99.9%.

Packingamount: theamountofsolidmatterof the packageisgivenmassofchemicalagent, suchas1g, 5g, 10g, 25g, 100g, 250g, 500g, 1000glike.Theliquidorgaseouschemicalsgivenamount of packagingvolume, suchas1ml,5ml, 10ml, 25ml, 100ml, 250ml, 500ml, 1000mland.

Appearance:concise,accuratetermtodescribethephysicalstateofthecolorofthechemicalagent,odor,andotherphysicalstate.

physica constantes: consequenter in ordine dato physico-constantiae mensurae valoris liquefactio, punctum fervens, densitas, viscositas, opticalrotatio, refractio coefficiens, solubilitas» et similia.

in quibus Spectrum:anda" UV, IR, NMRspectroscopia" aliae sunt notae.

interferingimpurities:primarilygivenmasspercentageofimpurities,inparticularthemaininterferenceaccuratemeasuredvalueofthemasspercentageofimpurities.

DGRNo:hazardousgoodsmustbemarkedDGRnumber.Productionbatch:givenproductionlotinordertofacilitatetraceability.

quibusforeigndevelopmentofchemicalreagents

tocompletedevelopment,alternatedirectionsreagentandancillaryservices

ancillarybenefits,likeimproveduserservice.Onforeignmarkets,almostindustrial,routineexperimentationandtestingprojectsinagriculture,health,environmentalprotection,scientificresearch,teaching,therearesetsofteststrip,completesolution,pre-filledcolumn,paintedsheets,variousreferencestandardandspecialeasytousetoolsandsmallequipment.Chemicalcompositionforeignmarketshasspecificreagents,suchasbasicmodulepeptide:p-aminoacids,FMOs(fluorenylmethoxycarbonylgroupZhuoyl)-aminoacidsandotheraminoacidsreagents;OrganicSynthesisbasicmodules:chloride,alcohol ,phenols,aldehydes,amines,carboxylicacids,ketones,andthelike;andreagentscustomizedaccordingtouserrequirements.MostReagentCompany,fortheconvenienceofusers,butalsosupportingsalesoflaboratoryinstrumentsoftenusedinsmall-scale,securesupplies,variousmapsdata(chemicalstructure,infrared,ultraviolet,emissionspectroscopy,chromatography,etc.),compoundsafetydata,variousdataanalysisandothertestingmethods,ofwhichaconsiderableportionispublishedonCD-Rom.

Manyagentsnotonlyselltangibleproducts,butalsotechnicalconsultingbusiness,providingawiderangeoftechnicalservices,suchas:analysisandtesting,intermediatescale-up,processdesignproducts,developenvironmentalprotectionprograms.

attachedgreatimportancetoscientificresearchanddevelopment

Thereagentscompanyhasitsownresearchanddevelopmentdepartment,mostcompaniesalsodevelopwithuniversities,researchinstitutes,individualscientistsorotherwell-knowncompanies,andevenmergersthecompanyhassometechnicalexpertise,inordertoenhancethecompany'sdevelopmentandcompetitiveness.Theyhesitatetoinvestheavilyinresearchanddevelopment,scienceandtechnologyinordertosuddenlyflyfierce,intothefiercecompetitioninthemarketdominantposition.ToMerckKGaA,forexample,their1994-Foreachyearbetween1998andfundsscientificresearchanddevelopmentinvestmentaccountedfortheproportionofsaleswere9.56%,9.O%,8.18%,9.76%and10.05%,overthesameperiod, Merck (Darm.) sic: 43.52%, 43.94%, 45.29%, 47.0% et 46.95%.

production

Mostofthecompany'sfactory,haveachievedISO9001,ISO9002,GMPorFDAqualitymanagementcertification.On-siteproductionprocess,industrialhygieneandenvironmentalprotectionwidespreadattention.Inrecentyears,withthecategoryofvarietiessupplymarketcontinuestoexpand,manyofthemorecomplextechnologyhasbeenwidelyadopted.Applicationofcomputer-aidedproduction,technology,businessmanagement,hasbeenverycommon.MostReagentCompany,arebuiltonitsownInternetsite,inadditiontoreportedcompanyhistory,institutionalstructure,businessscope,catalogandothervarieties,mainlyonlineshopping,andconstantly(aboutaweek)postedoperatingstatusofthecompany,technicalachievements,internationalcooperation,planningguidelinesandotherinformation.TheirannualfixedassetinvestmentinhugenumbertoMerckKGaA,forexample,from1994-1998theproportionofinvestmentinfixedassetssalesaccountedfor7.2%,8.4%,7.4%,6.7%,7.7%(eg:1998to624millionmarks,equivalenttoRMB2.8billionyuan).

alliancecooperation,jointoperationisatrend

varietycategoriesofchemicalagentsisextremelycomplicated,extensiveserviceside,involvingalmostalltheeconomicandtechnologicalfields,anycompany,wantstosweepreagentsallbusinessisimpossible,andreagentsalesischaracterizedbybiggerandmoreandmorevarietiesofbusiness,increasesalesopportunities,thegreaterthelikelihoodofthatisprofit.So,20yearsago,thereisatrendofsmallcompaniesmoveclosertolargecompanies,smallcompaniesorlargecorporatemergersofmutualco-operation.Headabletosupplytheworld'slargestspeciesistheSigma-A1drichcompany,theyadvantageinthevarietyisalmostirreplaceable,thisisindeedtheresultofajointoperation.

Thenewtrendinthecountrythroughtheestablishmentofe-commerceplatformtoachieveintegration,alliances,jointventureseffects,likeAvatar,chemistry,Seresagentsspecializeine-commercetradingplatformsuchreagentshasoccurred,thiswouldbeagoodintegrationofthedomesticagentresources.Becauseitconformstothedevelopmentofonlinesalesmodel,webelievethiswillbeamajortrendinthefuturereagentsbusiness.

safeuseofchemicalreagents

1.Chemicalsflammable

GeneralChemicalsflashpointbelow25℃flammablechemicalagentsincluded,theyaremostlyhighlyvolatileliquids,incaseoffiretoburn.Thelowertheflashpoint,themoreflammable.Commonflashpointpetroleumopened,ethylcondensateethane,diethylether,gasoline,twocarbonizedcarbon,withalkylenepropionate,benzene,ethylacetate,methylacetateinthefollowingyeast-4℃.

mustnotbeusedeasilywhenusingbrightfirealkenylChemicals.Heatcannotbedirectlyheatedbyaheater,generallydonothavewaterbath,suchchemicalagentsshouldbestoredinthecoolair,intherefrigerator,therefrigeratormustbeexplosionproof,therehadbeenstoredinaconventionalrefrigeratoretherandfire,accidentburnedtheentirelaboratory,wheretheuseofsuchalargenumberofchemicalreagents,looktomaintaingoodventilation,theuseofelectricalappliancesmustbeexplosion-proofelectricalequipment,thesitemustnothaveopenflames.

highlyflammablereagentsduringcombustioncanleadtoanexplosion,chemicalreagents,suchassomesolid:nitrocellulose,picricacid,trinitrotoluene,trinitrobenzene,oroverlappingazidecompound,saltHuoandsoon,frieditselfisburning,whenexposedtoheatorflame,whichburnseasilyordecomposition,explosion,itmustnotbeheateddirectlyintheuseofthesechemicals,shouldalsopayattentionsurroundingtheuseofthesechemicalsdonothaveanopenflame.

Anothertypeofsolidchemicalreagents,waterviolentreactioncanoccur,andemitalotofheat,cancauseanexplosion.Suchchemicalagentsaremetalpotassium,sodium,lithium,calcium,aluminumhydride,calciumcarbideandthelike,intheuseofthesechemicalagentsmustavoidtheirdirectcontactwithwater.

andsomesolidoncontactwithachemicalagentastrongoxidationcanoccur.Thephosphorus;somecontactwithanoxidizingagentorheatintheair,bytheimpactorfrictioncancauseabruptcombustionorexplosion.Thephosphorussulfide,redphosphorusmagnesium,zinc,aluminum,Rong,brainandthelikefall,whenusingthesechemicalagents,wemustpayattentionnottoohighambienttemperature(typicallynotmorethan30℃,preferably20℃orless)Avoidcontactwithstrongoxidizingagents.

Inthelaboratorypersonnelusingflammablechemicals,oughttowearthenecessaryprotectiveequipment,itisbesttowearprotectiveglasses.

2.ToxicChemicals

Generalchemicalsaretoxictohumans,mustbeavoidedwhenusingthelargenumberofinhalation,theagentperformancesAfteruse,towashtheirhands,wash,bath,replacingclothesforinhalationoringestionofsomesmallamountofdeaththatcanpoisonthechemicalagent,theamountofbiologicaltestdeath(LD50)isreferredtoastoxicchemicalagentsat50mg/kgorless,suchas:potassiumcyanide,sodiumcyanideandothercyanide,arsenictrioxideandcertainarsenide,mercurydichloride,mercuryandcertainsalts,sulfate,dimethylandthelike.Whenusingclearperformancechemicals,wemustunderstanditsLD50.Firstaidtreatmentatsomeofthecommonlyusedtoxicchemicalsmustunderstandthesetoxicchemicals,toxicchemicalsmusthaveaspecialpersontokeepstrictcontrolusage.

3.Corrosivechemicalagents

anychemicalagentacrosstheskin,mucousmembranes,eyes,respiratoryorgansmustbecleaned,inparticular,haveastrongcorrosivetotheskin,mucousmembranes,eyes,respiratorychemicalagents(whetherliquidorsolid),suchas:avarietyofacidsandbases,phosphorustrichloride,phosphorusoxychloride,bromine,phenol,Tianshuihydrazineandthelike.Butalsotoavoidhittingtheskin,mucousmembranes,eyes,respiratory,usebeforeusemustunderstandaidaccesstothesetreatmentmethodscorrosivechemicalagents.Usedilutealkalisuchasacidwashing,etc.spilledontheskin .

4.StrongoxidizingChemicals

strongoxidizingchemicalagentsareperoxidecontainingoxyacidorstrongoxidizingpoweranditssalts.Suchas:acidperoxide,Annnitrate,potassiumnitrate,perchloricacidandsaltsthereof,acidandsaltsthereofcomplexweight,permanganicacidanditssalts,peroxyacid,peraceticacid,sweetwine,phosphoruspentoxideandthelike.Strongoxidizingchemicalagentsunderappropriateconditionscanemitoxygenexplosion,andformexplosivemixtureswithorganicmagnesium,aluminum,zinc,sulfurandothercombustibles,somewatermayexplode,theuseofsuchastrongoxidizingchemicalinreagent,ambienttemperatureisnothigherthan30℃,goodventilationshouldnotbeorganicorreducingsubstanceswiththeuseofcommon(heating).

5.WhenRadiochemical

Theuseofsuchchemicalagents,theuseofradioactivematerialsaccordingtoacertainmethod,totakeprotectivemeasures.

distillationandrectificationchemicals

inthechemicalanalysis,instrumentalanalysis,thepreparationofinorganic,organicsynthesisandotherscientificexperimentareoftenencounteredwithinsufficientpuritychemicalsorbuytherequiredpuritychemicals,whichrequirespurificationofourownexistingchemicalsinthelaboratoryinordertoobtaintherequiredpuritychemicals.Apolloagentwillbesmallseriesfollowingbriefdistillationandrectificationmethods.

distillationandrectification

distillationandrectificationisawidelyusedmethodofpurification,mixingthecomponentsinaccordancewiththeliquidmixturebetweenliquidandvaportheinequalityofpurified,purificationisthefirstchoiceofvolatileandsemi-volatilechemicals.

adstillationprinciple

isseparatedbydistillationfromtheimpuritiescontainedinthechemicalagentvolatileandsemi-volatileimpuritiesandvolatileorsemi-volatileevaporatingbodyTheywillnotbevolatileandlessvolatileimpuritiesleftbehind.Changethesaturationvaporpressureofasubstanceatdifferenttemperaturesisthebasisoftheseparationbydistillation.Generallyspeaking,ifthevaporpressureoftheliquidmixtureoftwocomponentshavingalargedifferenceinthevaporphasecanbemorevolatileandsemi-volatilecomponentsenrichment.Twophases-liquidandvaporphases-canberecoveredseparately,volatileandsemi-volatilecomponentsintheenrichedvaporwithoutvolatilecomponentsareenrichedintheliquidphase.

Inadditiontothehydrocarbonmixtureandafewotherexamples,Raoult'slawandDalton'slawcanbeusedinsystemsoverthemixture,andthemixturesolutionisoftennotdesirabletofollowthevaporphase-phasebehavior.Applicationofthesetwolawscanbeavolatilethanthetwocomponentsofthebinarysystem(aAB):aAB=(YA/YB)/(XA/XB)=P0A/P0Bwherein,YAandYBaretheequilibriumcomponentsaandBinthegasphasemolefraction,XAandXBarethecomponentsaandBintheliquidphaseatequilibriummolefraction,andP0BareP0AvaporpressureofcomponentsaandBatequilibrium,obeysthelawsofRaouilt.WiththeincreaseaAB,alsoincreasesthedegreeofenrichment.

Secundo, asimpledistillation

simpledistillationapparatus,showninFigure-1.Whenaliquidsampleisheatedandconvertedintosteam,whichiscondensedpartbacktotheoriginaldistillationflask,whiletherestiscondensedandtransferredtoacollectionvessel,theformeriscalledrefluxliquid,whichiscalledeffluent.Sincethedistillationiscarriedoutcontinuously,escapeandstoredintheliquidcompositionisgraduallychanging.Asamethodofpurifyinganimpuritychemicalagents,separationonlysimpledistillationboilingpointhasalargedifference,suchastheboilingpointofthemainbodyofthedifferenceisgreaterthan50℃impurities.Toremoveimpuritieshavingaboilingpointoflessthan50deg.]Cwiththemaindifferenceis,willhavetouserectificationmethoddescribedbelow.

simpleatmosphericdistillationunitmainlyconsistsdistillationflask,thermometer,condenser,atrapandaheatingdevicewithasidetubeandothercomponents.Wheninstalled,themercurythermometershouldbeinsertedintotheballpositionlowerthanthesidetube,thesidetubeandacondenserconnectedtothedistillationflaskhorizontal,themouthandthecollectorconnectedtoacondenser(FIG.1).Whenusingadistillationapparatus,distilledaccordingtoboilingpointsoftheselectedtestchemicalheatingmeans:Thedistillationoftheliquidataboilingpointofless80℃,heatedwithhotwaterbath;liquidataboilingpointofabove100deg.]C,asbestosfireorbystraight-lineoilbath;liquidatatemperatureofabove200℃,heatingmetalbath.

distillationataboilingpointofabove150℃liquid,aircondensermaybeused.Inordertosmoothlycarryoutdistillation,andbeforeheating,thezeolitemustbeaddedaftertheliquidintheflaskchargedtotheflask.Becauseoftheverysmoothinnersurfaceoftheflask,andthebumpingpronetooverheating,sothatthedistillationcannotbecarriedoutsmoothly.Whenaddinganewzeolite,etc.mustAftercooledtoroomtemperaturebeforetheliquidwasaddedtotheflasktoavoidtheriskofboilingoccursabruptly.Zeoliteusedonlyonce,whentheliquidiscooled,addedtotheoriginalzeoliteloseseffect,sowhenthedistillationwascontinuedtobeaddedtothenewzeolite.Inatmosphericdistillation,havingaporous,easilycrushed,andthematerialwasdistilleddoesnotcausechemicalreactions,canbeusedasthezeolite.Zeolitesarecommonlycutinto1-2mmpiecesorunglazedclaytiles.

distillationapparatusisinstalled,theheatingcanbegin.Whenthesubstancebeginstoboilthedistillationflask,thetemperaturerisingsharply.Whenthetemperaturerisestotheboilingpointsubstanceweredistilleddown1℃,theintensityofheatingoftheheaterisadjustedtoalevelofadroppersecondeffluent.Inthiscase,theheatingtemperatureofthebathshouldbemaintainedathigherthantheboilingpointofthematerialinthedistillationflask20℃.Higherboilingmaterialdistillation,steamBeforei.e.lessthantheoutersidetubeandrefluxcoolingair,itcannotbedistilledoff.Atthistime,theflamecanbeuniformlyheatedusingamicrotubeofthelowersurfaceside,buttoavoidexcessiveheating,sothatthethermometerdoesnotindicatethecorrectboilingpoint,butalsoontheheatingportionoftheretortwithoutproperinsulation.Inthedistillationoperation,itshouldbenotedthefollowing:

(1)controltheheatingtemperature.Ifaheatingbath,thetemperatureoftheheatingbathshouldbeseveraldegreeshigherthantheboilingpointofthedistillationoftheliquid,otherwiseitisdifficulttobedistilledoutofthedistillate.Themoretheheatingbathtemperaturehigherthantheboilingpointoftheliquidofthedistillation,thedistillationfaster.However,thetemperatureoftheheatingbathcannotbetoohigh,otherwiseitwillleadtoanupperportionoftheretortandacondenservaporpressureaboveatmosphericpressure,anaccidentmayoccur,inparticular,moreparticularattentionduringdistillationlowboilers.Acamel,heatingbathtemperaturenothigherthantheboilingpointof30deg.]Cdistilledmaterial.

(2)distillingthehigh-boilingsubstances,condenseeasilybecause,oftendoesnotreachthevaporsideofthetube,i.e.thedistillationflaskhasbeencondenseddropsbackintothedistillationflask.Therefore,weshoulduseshort-neckedretortortakeinsulationmeasurestoensurethesmoothprogressofdistillation.

(3)priortothedistillation,thedistillationmustunderstandthechemicalagentandtheboilingpointandsaturatedvaporpressureimpurities,todeterminewhen(i.e.,atwhattemperature)tocollectpurechemicalagent.

(4) shall beinthedstillation flaskroundbottomflask.

aboilingpointof40-150deg.]CmaybeemployedChemicalssimpledistillationundernormalpressure.Chemicalsforboilingatabove150℃oraboilingpointbelow150deg.]C,although,butthermallylabile,thermallydecomposingthechemicalagent,maybeemployedsteamdistillationandvacuumdistillation,simplybeintroducedseparately.

1.Simplevacuumdistillationapparatus,theentiresystemconsistsofKirschnerportion(aClaisen)distillationflask,condenser,accumulator,suction(vacuum)system,interfacesandothercomponents.Wheninstallingavacuumdistillationunit,itshouldbenotedthatthedeviceissealed,goodqualitycorkmustbeselectedslightlylargerthanthediameterofthestopperflask.Corkmaterialshouldbeselecteddependingonthenatureoftheliquidsamplevapor.Ifthesteamdoesnotcauseerosionoftherubberstopper,rubberstopperusingeasilyremainsealed.Whenyouuseagoodqualitymatteappliances,butalsoeasytoremainsealed.Afterthedeviceisinstalled,beforestartingthedistillation,thesealmustbecheckedtoreducedpressuredistillationapparatus.Sealingdeviceinspectionmethodisconfirmedbymeasurementofchangeinpressureofthesystem,andifthepressurevaluedoesnotchange,indicatingthedevicedoesnotleakbeforedistillationunderreducedpressure.Whendistillationunderreducedpressure,thecapillarytubemaybeinsertedinthedistillationflasktopreventbumpingphenomenon.Theupperendofthecapillarytubeissealed,thelowerendisopen.Checkthatthesealedairtightafterdistillation,thepurifiedchemicalreagenttobeaddedtotheflask,theflaskwasaddedinanamounthalfthevolume,andthesystemevacuatedtoareducedpressurestate,andheatingisstarted.Theflaskwasimmersedinaheatingbathdepth,tobesurethatthebottleisbelowtheliquidsurfacelevelofsubstancedistilledheatingbath.Especiallyinahigh-boilingmaterialdistillation,theflaskwasimmerseddeepershouldtry.Whendistillationunderreducedpressure,oftenduetothepresenceoflowboilingsolventtoproduceafoam,requirealowdegreeofvacuumintheselow-boilingsolventwasdistilledoffbydistillationatthebeginning,andthengraduallyincreasethedegreeofvacuum.Lowvaporpressuredependsonthedegreeofvacuumoftheapparatusoftheliquidsample.Beforecoolingeffectmustbewelldistillates,otherwiseitisdifficulttoincreasethevacuumsystem.

Relationshipbetweenpressureandboilingpoint,canbeapproximatedoutbythefollowingformulaisderived: logP = A+(B/T)

whereinPisthevaporpressure,Tistheabsolutetemperature,A,Bisaconstant.Inpractice,theboilingpointcanbefoundinrelatedstressFIG.Whenthedistillationiscompletedistillationboilingpointcomponentsdesired,orwhenthedistillationprocessneedstobeinterrupted,heatingshouldbestopped,theheatingbathwasremoved,andaftercooling,slowlyreleasingthevacuumsystem,theapparatustoallowairtoenterthenormalpressureoffthevacuumpump.

steamdistillationistheseparationandpurificationmethodscommonlyusedinorganicmattersample,especiallyinthepresenceofalargenumberofresinousimpuritiesinthesampleupon.Thesamplewastreatedcompositionshouldmeetthefollowingconditions:thatisinsolubleoralmostinsolubleinwater,withboilingwaterduringprolongedcoexistencenochemicalchange,musthaveavaporpressureunderconditionsofgreaterthanabout100℃of10mmHg.

steamdistillation,isanothertechniqueforproducingheat-sensitivesamplesandforpurification.Itcanalsobeusedforgoodheattransferliquidsample,willdirectlycauselocaloverheatingheating.Steamdistillationmaybecompletedbycontinuouslysteamflowsthroughthevesselinthesamplemixture.Sometimestheuserdirectlyintotheflaskwithwaterforthesamepurpose.Steamcarryinggasphasevolatilecomponentandsuchalargeconcentratedvolatilematerialrelatedtotheirvaporpressureinthevapormixtureinthevapormixture.

Thistechniqueisverymild,duringthedistillationwillnotbedistilledmaterialisheatedtohigherthanthetemperatureofthesteam.Attheendoftheprocess,thesteamiscondensedandseparatedmaterial.Typically,theyareimmiscibleandmayformtwophasesareseparated.Sometimesanalyticalchemistmusthaveanadditionalsamplepreparationtechnique,suchasfluid-tocompletelyseparateaqueousandorganiclayersmultipleliquidextraction.

2.Simplemeansofsteamdistillation,Asteamgeneratoris,asthelevelgaugeglassBcanbeseenthattheheightofthewatersurfaceoccurs.Shengwaterisgenerallyappropriatecontainervolumeof75%,iftoofull,boilingwaterrushedtotheflask.SafetyglasstubeCisalmostinsertedinthebottomofthegeneratorA.Whenthepressureinsidethecontaineristoolarge,thewatercanrisealongtheglasstube,inordertoadjusttheinnerpressure.Ifthesystemisclogged,thewaterwillbeejectedfromtheupperopeningofthetube,itshouldbecheckedatthistimethesteamconduitundertheroundbottomflaskwhethertheportisblocked.Usingtheaboverectifyingpartgenerallynecked500mlroundbottomflask.Inordertopreventtheliquidinthebottleduetosplashjumpintothecondensertubes,sothatthepositionoftheflaskwastiltedby45degreesinthedirectionofthegenerator.Bottleofliquidsampleshouldnotexceed1/3ofitsvolume.EndofthesteamintroducingpipetobebentE,itisontheverticallyoutintothebottomofthebottleandclosethecentralbottom.SteamoutletpipeF(approximately30°angled)innerdiameterEispreferablylargerthanthenumberoftubes,insertoneendofthecorkwithtwoholes,exposingapproximately5mm,andtheotherendconnectedtothecondenser.DistillateliquidpipeintothereceptaclethroughtheaccessH.Availablewaterbathcoolingtheperipheralreceptacle.

inthesteamgeneratorandtheneckedroundbottomflaskshouldbeinstalledbetweenaT-shapedpipe,connectedatthelowerendofaT-piecespringclipG,inordertotimelyremovecondensedwaterdropletsclogging.When

steamdistillation,firstthesamplesolutionwasplacedinD.HeatingthesteamgeneratortonearboilinguntilaftertheGintensifythesteamevenlyintotheroundbottomflask.InordernottocondensethesteamandexcessiveaccumulationofD,itcanbesetatanetasbestosD,ifnecessary,tomakesmallflame.Heatingratemustbecontrolledsothatallthesteamcanbecondensedinthecondenser.Ifthevolatilesubstancewithwaterhavingahighermeltingpointvaporcondensedinthesolidwaseasilyprecipitated,itshouldadjusttheflowrateofthesmallcondensateaftercondensingitremainsliquid.Ifthesolidhasprecipitated,andthenearclogging,temporarilystopstheflowofcoolingwater,coolingwaterisevennecessarytotemporarilyletgo,sothatthemeltedmaterialflowsintothereceptaclewiththewater.Itmustbenoted,whenthecondensertobere-introducedintothejacketcoolingwater,needtobecarefullyandslowlyflowsinto,topreventquenchingduetorupturecondenser.Casehasbeenblockedcondenser,distillationwasstoppedimmediately,andtrytoclear.Suchasusingaglassrodtopokeoutorcloggingofmaterialtothehotwaterinacondensersoastomeltthetankjacket.

duringdistillationifitbreaksordistillationwascomplete,thespringclipmustfirstopenthethroughGatmosphere,thenheatingwasstopped,ortheliquidsuckedD,A,willbeinverted.Duringthedistillation,thewaterlevelrisesrapidlyiffoundsafeintubeC,thencloggingoccursinthesystem,thenitshouldimmediatelyopenthespringclipG,andthentheheatwasremoved.Beexcludedbeforecontinuingpluggingsteamdistillation.

III.Rectification

fractionaldistillationiscarriedoutbyfractionaldistillationcolumninthedistillationprocess,thechemicalagentisrectifiedinthedistillationflaskafterboiling,thesteamfromthegardenbottomflaskevaporatesintoafractionatingcolumn,condensedinthefractionatingcolumnintoaliquidportion.Theliquidduetohighcontentoflow-boilingcomponents,andthereforealsolowerthantheboilingpointoftheliquidtemperatureinthedistillationflask.Whenthedistillationflasktoanotherportionofthevaporrisesinthefractionationcolumn,andthentheliquidhascondensedbyheatexchange,re-boilingit,whiletheascendingvaporispartiallycondensedinitself,andtherefore,ithasproducedanewtheliquid-vaporequilibrium,theresultsofthelow-boilingcomponentinthevaporhaveincreased.Whenthenewvaporriseswithinthedistillationcolumn,andiscondensedintoaliquid,andthenbyheatexchangewithanotherportionoftheascendingvaporboils.Duetoconstantlyascendingvaporcondensationandevaporationfractionatingthecolumn,andeachtimebothevaporationandcondensationofthesteaminthelow-boilingcomponentcontinuestoincrease.Accordingly,duringascentofsteaminthefractionatingcolumn,similarlyrepeatedaftersimpledistillationofthelowboilingcomponentthevaporgraduallyincrease.Thus,inthefractionationprocessiscriticaldephlegmatorapparatus,ifappropriateselectedfractionatingcolumncancomeoutatthetopofthefractionatingcolumnvaporcondensedandtheresultingliquidmaybeapurecomponentoralow-boilinglow-boilingaccountedeffluentmaincomponent.

fractionationcapacityandefficiencyofthefractionationcolumn,respectively,as"theoreticalplatesvalue"and"heightequivalenttheoreticalplate(theHETP)"represented.Avalueequivalenttoatheoreticalplatesimpledistillation.Thedistillationcolumnhavingafractionatingcapabilityofthesame,whichisnotnecessarilyequallength.Forexample:A,Btwodephlegmator,theirvalues​​are20theoreticalplates,Aistheheightof60cmandaheightof20cmacetate.Obviously,boththeoreticalplateheightequivalentisdifferent.Becausetheheightequivalentoftheoreticalplate:

HETP=heightofthedistillationcolumn/theoreticalplatenumber

Therefore,theoreticalplatesAfractionatingcolumnheightequivalentof3cm,andacetatetheoreticalplatesfractionatingcolumnheightequivalentof1cm.Itcanbeseenthroughthisexample,theequivalentoftheoreticalplatesofthedistillationcolumnheightislower,thehigheritsefficiencyinfractionationunitlength.

Duringdistillationoperation,themainfractionatingcolumnselectedaccordingtotheleveldifferencebetweentheboilingpointandtheboilingpointofthechemicalagentintherectificationbodywithimpurities.Ifthedifferenceinboilingpointinthetwocomponentsabove100℃,afractionatingcolumnmaynotbeused;iftheboilingpointdifferenceisabout25℃,optionallyconventionalfractionatingcolumn;iftheboilingpointdifferenceisabout10℃,requireselaboratefractionatingcolumn,suchasmicro-Grofractionatingcolumnandthelike.Distillationprocessusingtheheatsourcemustbestabletoensureaheatingtemperaturestable.Onlystrictcontrolandconstantheatinginordertomaintainthedesiredrefluxratio.Ifheatedtooquickly,willproducefloodingphenomenon,thefractionationefficiencyispoor.Iftheheatingistooslow,youcanonlyplaytheroleofafractionatingcolumnrefluxcondenser,simplydistilledoutanything.Further,atthetimeofdistillation,refluxanddistillaterequiresanappropriateratio,i.e.refluxratioshouldbeappropriate,itsvalueisequaltothevalueoftheoreticalplatesfractionatingcolumnsubstantiallyso,tomakethenormaldistillationprocess.

IV.Thepracticalapplicationofdistillationandrectification

distillationandrectificationmainlyusedforliquidorheatingliquidcanbeachemicalagent,inparticularfororganicchemicalspurification.Priortodistillationorrectification,sometimestheadditionofcertainchemicalreagents,chemicalreactionwithachemicalreagenttobepurifiedofimpuritiesoccurs,generatingahigherboilingpoint(orless)substance,ismoreeasilyremovedinadistillationorrectification.

duringdistillationorrectification,isoftenthefirstdistillatefractionisremovedandthefinalremainingfraction,twoofthemoreremoved,thehigherthepurityofthechemicalagent,buttheloweryields.