大气中NO_2浓度的测定方法—Sodium Arsenite法-豆柴文库

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大气中NO_2浓度的测定方法—SodiumArsenite法
Title:DeterminationofNO2ConcentrationintheAtmosphere-SodiumArseniteMethod
Abstract:
Themeasurementofnitrogendioxide(NO2)concentrationintheatmosphereiscrucialforassessingairqualityanditsimpactonhumanhealthandtheenvironment.ThispaperexplorestheSodiumArsenitemethodforthedeterminationofNO2concentration.TheSodiumArsenitemethodinvolvesthereductionofNO2toNOandsubsequenttitrationwithaSodiumArsenitesolution.Theprinciples,procedures,advantages,andlimitationsofthismethodarediscussed.Additionally,potentialapplicationsandfuturedevelopmentsinNO2concentrationmeasurementareaddressed.
1.Introduction:
Nitrogendioxide(NO2)isoneoftheprimaryairpollutantsemittedfromvariousanthropogenicactivitiessuchascombustionprocesses,industrialactivities,andtransportation.HighlevelsofNO2intheatmospherecanhavedetrimentaleffectsonhumanhealth,contributingtorespiratoryandcardiovasculardiseases.Therefore,accurateandreliablemethodsformeasuringNO2concentrationareessentialformonitoringairqualityandimplementingeffectivepollutioncontrolstrategies.
2.SodiumArseniteMethod:
TheSodiumArsenitemethodisawidelyusedtechniqueforNO2concentrationdetermination.Itinvolvesthefollowingsteps:
a.Sampling:AirsamplesarecollectedusingasamplingdevicecapableoftrappingNO2molecules.Commonsamplingdevicesincludepassivesamplersandcontinuousanalyzers.
b.Conversion:SampledairispassedthroughaconverterwhereNO2isconvertedtonitricoxide(NO)inthepresenceofareducingagentsuchasozoneormolybdenumcatalyst.
c.Titration:TheconvertedNOisthentitratedusingastandardizedSodiumArsenitesolution.TheSodiumArsenitereactswithNO,producingabrownish-yellowcolorchangeduetotheformationofArsenicTriiodide(AsI3).Theendpointofthetitrationisdeterminedvisuallyorwiththehelpofacolorimeter.
d.Calculation:TheNO2concentrationiscalculatedbasedonthevolumeoftheSodiumArsenitesolutionusedfortitration,thesamplevolume,andcalibrationfactors.
3.AdvantagesofSodiumArseniteMethod:
i.Sensitivity:TheSodiumArsenitemethodishighlysensitiveandcandetectNO2atlowconcent