分光光度法间接测定电镀废水中的氮基磺酸英文BDeepa

•46•【分析测试】IndirectspectrophotometricdeterminationofsulfamicacidinelectroplatingeffluentsB.Deepa1,*,K.S.Nagaraja1,N.Balasubramanian2,MaryGeorge3,**(1.DepartmentofChemistry,LoyolaInstituteofFrontierEnergy(LIFE),LoyolaCollege,Chennai-600034,India;2.DepartmentofChemistry,IndianInstituteofTechnology,Chennai-600036,India;3.DepartmentofChemistry,StellaMarisCollege,Chennai-600086,India)Abstract:Aproposedspectrophotometricmethodforthedeterminationofsulfamicacidinvolvesreactionofsulfamicacidwithknownexcessofnitrite.Theunreactednitriteisdeterminedbydiazocouplingreactioninvolvingp-nitro-anilineandN-(1-naphthyl)ethylenediaminedihydrochloride[NEDA].Theabsorptionmaximum(λmax)fortheformedazodyeisat545nmandthecalculatedmolarabsorptivityis6.1×104L/(mol·cm).Themethodisusefulfordeterminingsulfamicacidintherangeof0-25μginanoverallvolumeof25mL,andtherelativestandarddeviationis2%forn=10at15μglevelofsulfamicacid.Thedevelopedmethodwasappliedtothedeterminationofsulfamicacidintheeffluentsofnickel,lead,iron,rutheniumandindiumsulfamateelectroplatingbaths.Theresultsobtainedwerevalidatedbyrecoverystudiesofaddedsulfamicacid.Keywords:sulfamicacid;diazocoupling;spectrophotometry;electroplatingeffluentCLCnumber:TQ153.12Documentcode:AArticleID:1004–227X(2010)11–0046–05分光光度法间接测定电镀废水中的氨基磺酸//DEEPAB,NAGARAJAKS,BALASUBRAMANIANN,GEORGEM摘要：提出了一种利用已知过量的亚硝酸盐与氨基磺酸反应，对氨基磺酸进行分光光度测定的方法。未反应的亚硝酸根采用其与对硝基苯胺及N–(1–萘基)乙二胺二盐酸盐(NEDA)之间的重氮偶合反应来测定。所生成的偶氮染料的最大吸收波长为545nm，实测摩尔吸光度为6.1×104L/(mol·cm)。该方法可用于测量总体积为25mL的样品中0~25μg的氨基磺酸。当样本数为10时，测定15μg氨基磺酸的相对标准偏差为2%。将该方法用于测定镍、铅、铁、钌、铟等金属的氨基磺Receiveddate:2010–06–01Biography:Dr.B.DeepaobtainedherMastersandDoctoratedegreefromMadrasUniversity.Herresearchareaofinterestliesinthedevelopmentofnovelanalyticalmethodsfordeterminationoftoxicwaterpollutants.Shehastohercreditfivearticlesininternationallyrefereedjournals.PresentlysheisaregisteredIndianpatentattorneydealingwithIntellectualpropertyrights.Correspondingauthors:Dr.B.Deepa,(E-mail)[e-mail];Dr.M.George,(E-mail)[e-mail].酸盐电镀液废水中氨基磺酸的含量，其结果采用加标回收率方法进行了验证。关键词：氨基磺酸；重氮偶合；分光光度法；电镀废水1IntroductionSulfamicacidhasauniquecombinationofpropertiesthatmakesitparticularlywellsuitedforscaleremovalandchemicalcleaningoperations.Saltsofsulfamicacidareusedinelectroplatingandelectro-formingoperationsaswellasformanufacturingflame-retardantsandweedkillers[1].Becausesulfamatesaltsarehighlysoluble,higherconcentrationofmetalionscanbeattainedwhichpermithigherratesofplatingthansulfatebaths[2].Sulfamatesusedinplatingsolutionsincludethesaltsofnickel,cobalt,cadmium,iron,ruthenium,palladium,indiumandlead.ThenickeldepositsfromsulfamatebathsareharderandlessductilewithlowinternalstressesascomparedtodepositsfromadditivefreeWatt’sbath.NickeldepositsfromsulfamatebathareconsiderablystrongeratcryogenictemperaturethandepositfromWatt’sbath[3].Nickelsulfamatebathsareusuallyemployedtoproducedepositsforengineeringpurposeswiththecontrolofmechanicalpropertiessuchasstress,ductilityandhardness.Sulfamatebathsareprimarilyusedinindustrialnickelplatingandelectroformingwherelowinternalstressofthedeposit,highplatingratesareofpracticalimportance.Besidesbeingreactive,sulfamicacidanditssaltsarecorrosivetoeyes,skinandrespiratorytrack.Inhalationmaycausepulmonaryedema,whichcanbedelayedforseveralhoursandthereisariskofdeathinseriouscases[4].TheexposurelimitofsulfamicacidaccordingtoAmericanDOI:10.19289/j.1004-227x.2010.11.014Indirectspectrophotometricdeterminationofsulfamicacidinelectroplatingeffluents•47•ConferenceofGovernmentalIndustrialHygiene(ACGIH)wasfoundtobe10mg/m3andOccupationalSafetyandHealthAdministration(OSHA)wasfoundtobe15mg/m3(total)and5mg/m3(resp).Hencethedeterminationofresidualamountsofsulfamicacidintheeffluentsofsulfamatebathsisessential.Therearereportsavailableintheliteratureforthedeterminationofsulfamicacidbytechniquesasvariedasgravimetry[5],gasometry[6-7]andtitrimetry[8].Therecentspectrophotometricmethodreportedforthetracedeterminationofsulfamicacidinvolvesacidhydrolysisofsulfamicacidtoformammoniumsulfate.TheformedammoniumsulfatewasdeterminedbasedonBerthelotreaction[9].Inthisstudy,sulfamicacidisindirectlydeterminedbyafacileandsensitivespectrophotometricmethodbasedondiazo-couplingreaction.2ExperimentalAllabsorbancemeasurementsweremadeusingElicoSL177scanningspectrophotometerwith1cmglasscells.2.1ReagentsAllchemicalsusedwereanalyticalgradereagentsanddistilledwaterwasusedintheirpreparations.Standardsulfamicacidsolution(1000ppm)waspreparedbydiluting0.1000gofsulfamicacidin100mLofdistilledwater.Workingstandardsof100ppmand5ppmwerepreparedbydilution.Nitritesolution(1000ppm)waspreparedbydiluting0.1500gofsodiumnitritein100mLofdistilledwater.Asuitablealiquotofthissolutionwasdilutedtoget15ppmofnitrite.p-Nitroaniline(0.05%)waspreparedbydissolving0.05gofthereagentin100mLof1:1hydrochloricacid.N-(1-naphthyl)ethylenediaminedihydrochloride[NEDA](0.1%)waspreparedbydissolving0.1ginwateranddilutingitto100mL.Sulfuricacid(2N)waspreparedbydiluting36Nconcentratedsulfuricacid(specificgravity:1.84)withdistilledwater.Formicacidsolutio