總磷的測(cè)定DeterminationofTotalPhosphorous主講教師：楊文婷Lecturer:YangWenting設(shè)備與環(huán)境學(xué)院建筑環(huán)境工程教學(xué)團(tuán)隊(duì)TeachingTeamofBuildingEnvironmentalEngineering,SchoolofEquipmentandEnvironment課程導(dǎo)入Introduction

總磷是水中的各種形態(tài)的磷轉(zhuǎn)變成正磷酸鹽的總數(shù)，總磷是水體富含有機(jī)質(zhì)的指標(biāo)之一。磷含量過多會(huì)引起藻類植物的過度生長(zhǎng)，水體富營(yíng)養(yǎng)化，打亂水體的平衡，因此檢測(cè)水中的含磷量十分重要。Totalphosphorusrepresentsthesumofvariousformsofphosphorusinwaterthathavebeenconvertedintoorthophosphate,anditisoneoftheindicatorsthatawaterbodyisrichinorganicmatter.Excessivephosphoruscontentcanleadtotheovergrowthofalgae,waterbodyeutrophicationanddisruptionofwaterbalance.Therefore,itisveryimportanttodetectthephosphoruscontentinwater.實(shí)驗(yàn)?zāi)康腅xperimentalPurposes01一、實(shí)驗(yàn)?zāi)康腅xperimentalPurpose

01了解磷（總磷、溶解性正磷酸鹽和溶解性總磷）的測(cè)定方法Understandthemethodfordeterminationofphosphorus(totalphosphorus,dissolvedorthophosphateanddissolvedtotalphosphorus)02熟悉鉬酸銨分光光度法測(cè)定總磷的原理和過程Befamiliarwiththeprincipleandprocessofammoniummolybdatespectrophotometryfordeterminationoftotalphosphorus03掌握分光光度計(jì)的使用、標(biāo)準(zhǔn)曲線的繪制及計(jì)算方法Mastertheuseofspectrophotometer,drawingofstandardcurveandcalculationmethod實(shí)驗(yàn)原理ExperimentalPrinciples02在酸性介質(zhì)中，正磷酸鹽與鉬酸銨反應(yīng)，在銻鹽存在下生成磷鉬雜多酸后，立即被抗壞血酸還原，生成藍(lán)色的絡(luò)合物。該絡(luò)合物在700nm處有最大吸收，據(jù)此可分析水中的總磷。Inacidicmedium,orthophosphatereactswithammoniummolybdatetoformaphosphomolybdicheteropolyacidinthepresenceofantimonysalt.Itisthenpromptlyreducedbyascorbicacidtoproduceabluecomplex.Thecomplexexhibitsmaximumabsorptionat700nm,accordingtowhichtotalphosphorusinwatercanbeanalyzed.PO43-+鉬酸鹽+抗壞血酸PO43-+molybdate+ascorbicacidH+藍(lán)色絡(luò)合物（磷鉬藍(lán)）Bluecomplex(phosphorusmolybdenumblue)二、實(shí)驗(yàn)原理ExperimentalPrinciples實(shí)驗(yàn)儀器及試劑ExperimentalInstrumentsandReagents03三、實(shí)驗(yàn)儀器及試劑Experimentalinstrumentsandreagents

分光光度計(jì)Spectrophotometer容量瓶Volumetricflask比色管Colorimetrictube比色皿Cuvette移液管Pipette燒杯若干Beakers實(shí)驗(yàn)儀器

ExperimentalInstruments*注：所有玻璃器皿均應(yīng)用稀鹽酸或稀硝酸浸泡*Note:Allglasswareshallbesoakedwithdilutehydrochloricacidordilutenitricacid實(shí)驗(yàn)試劑Reagents純水Purifiedwater磷標(biāo)準(zhǔn)貯備溶液50μg/mLPhosphorusstandardstocksolution50

μg/mL鉬酸鹽溶液Molybdatesolution抗壞血酸100g/LAscorbicacid100

g/L磷標(biāo)準(zhǔn)使用溶液2μg/mLPhosphorusstandardworkingsolution2

μg/mL三、實(shí)驗(yàn)儀器及試劑Experimentalinstrumentsandreagents

實(shí)驗(yàn)步驟ExperimentalProcedure04實(shí)驗(yàn)步驟ExperimentalProcedure1.標(biāo)準(zhǔn)曲線的繪制Plottingofstandardcurve2.樣品測(cè)定Sampledetermination四、實(shí)驗(yàn)步驟Experimentalprocedure1.標(biāo)準(zhǔn)曲線的繪制Plottingofstandardcurve四、實(shí)驗(yàn)步驟Experimentalprocedure記錄數(shù)據(jù)

RecordingData等待顯色時(shí)，填寫表格內(nèi)容Fillinthetablewhenwaitingforcolordevelopment測(cè)定吸光度，將吸光度記錄至表格對(duì)應(yīng)位置Determinetheabsorbanceandrecorditinthecorrespondingcellofthetable讀數(shù)保留兩位小數(shù)。Readingtotwodecimalplaces.表1分光光度法測(cè)定樣品中總磷標(biāo)準(zhǔn)曲線繪制Table1StandardCurveDrawingforDeterminationof

TotalPhosphorusinSamplesbySpectrophotometry實(shí)驗(yàn)項(xiàng)目ExperimentItem1234567備用Standby移取磷標(biāo)液體積(mL)Thevolumeofphosphorusstandardsolution(mL)0ml1ml3ml5ml8ml10ml15ml

取抗壞血酸液體積(mL)Thevolumeofascorbicacidsolution(mL)1ml1ml1ml1ml1ml1ml1ml

取鉬酸銨液體積(mL)Thevolumeofammoniummolybdatesolution(mL)2ml2ml2ml2ml2ml2ml2ml

吸光度(A1)Absorbance(A1)0.017

含磷溶液濃度(mg/L)Hydrochloricacidsolutionconcentration(mg/L)00.040.120.200.320.400.60

工作曲線Workingcurve

相關(guān)系數(shù)R=CorrelationcoefficientR=四、實(shí)驗(yàn)步驟Experimentalprocedure后期包裝Laterpackaging記錄數(shù)據(jù)RecordingData表2分光光度法測(cè)定樣品中總磷測(cè)定Table2DeterminationofTotalPhosphorusinSamplesbySpectrophotometry項(xiàng)目Item樣品1Sample1樣品2Sample2備用Standby正磷酸鹽吸光度Orthophosphateabsorbance

從校準(zhǔn)曲線中查得總磷質(zhì)量(mg/L)Totalphosphoruscontentfromthecalibrationcurve(mg/L)

樣品中總磷含量(mg/L)Totalphosphoruscontentinsample(mg/L)

平均值(mg/L)MeanValue(mg/L)

極差Range

相對(duì)極差(%)Relativerange(%)測(cè)定吸光度，將吸光度記錄至表格對(duì)應(yīng)位置Determinetheabsorbanceandrecorditinthecorrespondingcellofthetable讀數(shù)保留兩位小數(shù)。Readingtotwodecimalplaces.四、實(shí)驗(yàn)步驟Experimentalprocedure2.樣品測(cè)定Sampledetermination四、實(shí)驗(yàn)步驟Experimentalprocedure數(shù)據(jù)處理DataProcessing05表1分光光度法測(cè)定樣品中總磷標(biāo)準(zhǔn)曲線繪制Table1StandardCurveDrawingforDeterminationofTotalPhosphorusinSamplesbySpectrophotometry實(shí)驗(yàn)項(xiàng)目ExperimentItem1234567備用Standby移取磷標(biāo)液體積(mL)Thevolumeofphosphorusstandardsolution(mL)0ml1ml3ml5ml8ml10ml15ml

取抗壞血酸液體積(mL)Thevolumeofascorbicacidsolution(mL)1ml1ml1ml1ml1ml1ml1ml

取鉬酸銨液體積(mL)Thevolumeofammoniummolybdatesolution(mL)2ml2ml2ml2ml2ml2ml2ml

吸光度(A1)Absorbance(A1)0.0170.0410.0850.1310.1960.2410.347

含磷溶液濃度(mg/L)Hydrochloricacidsolutionconcentration(mg/L)00.040.120.200.320.400.60

工作曲線Workingcurvey=0.5503x+0.0191相關(guān)系數(shù)R=CorrelationcoefficientR=計(jì)算過程Calculationprocess繪制標(biāo)準(zhǔn)曲線：Drawastandardcurve:1計(jì)算出標(biāo)準(zhǔn)曲線公式Calculatethestandardcurveformulay=0.5503x+0.0191

2計(jì)算R值CalculateRvalueR2=0.99983計(jì)算過程Calculationprocess1.標(biāo)準(zhǔn)曲線的繪制Plottingofstandardcurve五、數(shù)據(jù)處理DataProcessing項(xiàng)目

Item正磷酸鹽吸光度Orthophosphateabsorbance從標(biāo)準(zhǔn)曲線中查得總磷含量

Totalphosphoruscontentfromthestandardcurve(mg/L)樣品中總磷含量Totalphosphoruscontentinsample(mg/L)平均值

Mean(mg/L)極差Range相對(duì)極差Relativerange樣品1Sample1樣品2Sample2備用Standby表2分光光度法測(cè)定樣品中總磷測(cè)定Table2DeterminationofTotalPhosphorusinSamplesbySpectrophotometry0.20.18（3.29+3.28）/2=3.2853.29-3.28=0.010.01/3.285*100%=0.304%2.樣品測(cè)定Sampledetermination3.293.283.293.28計(jì)算過程Calculationprocess從標(biāo)準(zhǔn)曲線中查得總磷含量(mg/L)Totalphosphoruscontentfromthestandardcurve(mg/L)12計(jì)算樣品中總磷含量：Calculatethetotalphosphoruscontentofsamples:總磷（P，mg/L）=C×50/VTotalphosphorus(P,mg/L)=C×50/V3計(jì)算樣品的平均值Calculatethemeanforthesamples4計(jì)算總磷的極差Calculatetherangeoftotalphosphorus5計(jì)算總磷的相對(duì)極差Calculatetherelativerangeoftotalphosphorus6式中：V——水樣體積，mL；Where:V-Volumeofwatersample,mL;五、數(shù)據(jù)處理DataProcessing注意事項(xiàng)Precautions061、如果水樣總磷不超過0.5mg/L,可以直接吸取一定的體積，直接按照上述操作步驟測(cè)定。Ifthetotalphosphorusinwatersampledoesnotexceed0.5mg/L,acertainvolumecanbedirectlypipettedandanalyzedf