总磷的测定-Determination of Total Phosphorou36课件讲解

总磷的测定DeterminationofTotalPhosphorous主讲教师：杨文婷Lecturer:YangWenting设备与环境学院建筑环境工程教学团队TeachingTeamofBuildingEnvironmentalEngineering,SchoolofEquipmentandEnvironment课程导入Introduction

总磷是水中的各种形态的磷转变成正磷酸盐的总数，总磷是水体富含有机质的指标之一。磷含量过多会引起藻类植物的过度生长，水体富营养化，打乱水体的平衡，因此检测水中的含磷量十分重要。Totalphosphorusrepresentsthesumofvariousformsofphosphorusinwaterthathavebeenconvertedintoorthophosphate,anditisoneoftheindicatorsthatawaterbodyisrichinorganicmatter.Excessivephosphoruscontentcanleadtotheovergrowthofalgae,waterbodyeutrophicationanddisruptionofwaterbalance.Therefore,itisveryimportanttodetectthephosphoruscontentinwater.实验目的ExperimentalPurposes01一、实验目的ExperimentalPurpose

01了解磷（总磷、溶解性正磷酸盐和溶解性总磷）的测定方法Understandthemethodfordeterminationofphosphorus(totalphosphorus,dissolvedorthophosphateanddissolvedtotalphosphorus)02熟悉钼酸铵分光光度法测定总磷的原理和过程Befamiliarwiththeprincipleandprocessofammoniummolybdatespectrophotometryfordeterminationoftotalphosphorus03掌握分光光度计的使用、标准曲线的绘制及计算方法Mastertheuseofspectrophotometer,drawingofstandardcurveandcalculationmethod实验原理ExperimentalPrinciples02在酸性介质中，正磷酸盐与钼酸铵反应，在锑盐存在下生成磷钼杂多酸后，立即被抗坏血酸还原，生成蓝色的络合物。该络合物在700nm处有最大吸收，据此可分析水中的总磷。Inacidicmedium,orthophosphatereactswithammoniummolybdatetoformaphosphomolybdicheteropolyacidinthepresenceofantimonysalt.Itisthenpromptlyreducedbyascorbicacidtoproduceabluecomplex.Thecomplexexhibitsmaximumabsorptionat700nm,accordingtowhichtotalphosphorusinwatercanbeanalyzed.PO43-+钼酸盐+抗坏血酸PO43-+molybdate+ascorbicacidH+蓝色络合物（磷钼蓝）Bluecomplex(phosphorusmolybdenumblue)二、实验原理ExperimentalPrinciples实验仪器及试剂ExperimentalInstrumentsandReagents03三、实验仪器及试剂Experimentalinstrumentsandreagents

分光光度计Spectrophotometer容量瓶Volumetricflask比色管Colorimetrictube比色皿Cuvette移液管Pipette烧杯若干Beakers实验仪器

ExperimentalInstruments*注：所有玻璃器皿均应用稀盐酸或稀硝酸浸泡*Note:Allglasswareshallbesoakedwithdilutehydrochloricacidordilutenitricacid实验试剂Reagents纯水Purifiedwater磷标准贮备溶液50μg/mLPhosphorusstandardstocksolution50

μg/mL钼酸盐溶液Molybdatesolution抗坏血酸100g/LAscorbicacid100

g/L磷标准使用溶液2μg/mLPhosphorusstandardworkingsolution2

μg/mL三、实验仪器及试剂Experimentalinstrumentsandreagents

实验步骤ExperimentalProcedure04实验步骤ExperimentalProcedure1.标准曲线的绘制Plottingofstandardcurve2.样品测定Sampledetermination四、实验步骤Experimentalprocedure1.标准曲线的绘制Plottingofstandardcurve四、实验步骤Experimentalprocedure记录数据

RecordingData等待显色时，填写表格内容Fillinthetablewhenwaitingforcolordevelopment测定吸光度，将吸光度记录至表格对应位置Determinetheabsorbanceandrecorditinthecorrespondingcellofthetable读数保留两位小数。Readingtotwodecimalplaces.表1分光光度法测定样品中总磷标准曲线绘制Table1StandardCurveDrawingforDeterminationof

TotalPhosphorusinSamplesbySpectrophotometry实验项目ExperimentItem1234567备用Standby移取磷标液体积(mL)Thevolumeofphosphorusstandardsolution(mL)0ml1ml3ml5ml8ml10ml15ml

取抗坏血酸液体积(mL)Thevolumeofascorbicacidsolution(mL)1ml1ml1ml1ml1ml1ml1ml

取钼酸铵液体积(mL)Thevolumeofammoniummolybdatesolution(mL)2ml2ml2ml2ml2ml2ml2ml

吸光度(A1)Absorbance(A1)0.017

含磷溶液浓度(mg/L)Hydrochloricacidsolutionconcentration(mg/L)00.040.120.200.320.400.60

工作曲线Workingcurve

相关系数R=CorrelationcoefficientR=四、实验步骤Experimentalprocedure后期包装Laterpackaging记录数据RecordingData表2分光光度法测定样品中总磷测定Table2DeterminationofTotalPhosphorusinSamplesbySpectrophotometry项目Item样品1Sample1样品2Sample2备用Standby正磷酸盐吸光度Orthophosphateabsorbance

从校准曲线中查得总磷质量(mg/L)Totalphosphoruscontentfromthecalibrationcurve(mg/L)

样品中总磷含量(mg/L)Totalphosphoruscontentinsample(mg/L)

平均值(mg/L)MeanValue(mg/L)

极差Range

相对极差(%)Relativerange(%)测定吸光度，将吸光度记录至表格对应位置Determinetheabsorbanceandrecorditinthecorrespondingcellofthetable读数保留两位小数。Readingtotwodecimalplaces.四、实验步骤Experimentalprocedure2.样品测定Sampledetermination四、实验步骤Experimentalprocedure数据处理DataProcessing05表1分光光度法测定样品中总磷标准曲线绘制Table1StandardCurveDrawingforDeterminationofTotalPhosphorusinSamplesbySpectrophotometry实验项目ExperimentItem1234567备用Standby移取磷标液体积(mL)Thevolumeofphosphorusstandardsolution(mL)0ml1ml3ml5ml8ml10ml15ml

取抗坏血酸液体积(mL)Thevolumeofascorbicacidsolution(mL)1ml1ml1ml1ml1ml1ml1ml

取钼酸铵液体积(mL)Thevolumeofammoniummolybdatesolution(mL)2ml2ml2ml2ml2ml2ml2ml

吸光度(A1)Absorbance(A1)0.0170.0410.0850.1310.1960.2410.347

含磷溶液浓度(mg/L)Hydrochloricacidsolutionconcentration(mg/L)00.040.120.200.320.400.60

工作曲线Workingcurvey=0.5503x+0.0191相关系数R=CorrelationcoefficientR=计算过程Calculationprocess绘制标准曲线：Drawastandardcurve:1计算出标准曲线公式Calculatethestandardcurveformulay=0.5503x+0.0191

2计算R值CalculateRvalueR2=0.99983计算过程Calculationprocess1.标准曲线的绘制Plottingofstandardcurve五、数据处理DataProcessing项目

Item正磷酸盐吸光度Orthophosphateabsorbance从标准曲线中查得总磷含量

Totalphosphoruscontentfromthestandardcurve(mg/L)样品中总磷含量Totalphosphoruscontentinsample(mg/L)平均值

Mean(mg/L)极差Range相对极差Relativerange样品1Sample1样品2Sample2备用Standby表2分光光度法测定样品中总磷测定Table2DeterminationofTotalPhosphorusinSamplesbySpectrophotometry0.20.18（3.29+3.28）/2=3.2853.29-3.28=0.010.01/3.285*100%=0.304%2.样品测定Sampledetermination3.293.283.293.28计算过程Calculationprocess从标准曲线中查得总磷含量(mg/L)Totalphosphoruscontentfromthestandardcurve(mg/L)12计算样品中总磷含量：Calculatethetotalphosphoruscontentofsamples:总磷（P，mg/L）=C×50/VTotalphosphorus(P,mg/L)=C×50/V3计算样品的平均值Calculatethemeanforthesamples4计算总磷的极差Calculatetherangeoftotalphosphorus5计算总磷的相对极差Calculatetherelativerangeoftotalphosphorus6式中：V——水样体积，mL；Where:V-Volumeofwatersample,mL;五、数据处理DataProcessing注意事项Precautions061、如果水样总磷不超过0.5mg/L,可以直接吸取一定的体积，直接按照上述操作步骤测定。Ifthetotalphosphorusinwatersampledoesnotexceed0.5mg/L,acertainvolumecanbedirectlypipettedandanalyzedf