现代分析分析技术-第一章-XRF-(制样方法)

现代分析测试技术Modernanalyticandtestingtechnologies讲授教师：林旭聪Institutions：福州大学化学学院Address：旗山校区杨鸿耀楼433室Folie.2©2001BrukerAXSAllRightsReservedX射线荧光光谱分析技术之二：制样方法制样的目的：1、均匀2、重复性好3、颗粒效应小4、矿物效应小5、无限厚（薄膜法除外）Folie.3©2001BrukerAXSAllRightsReserved分析层的厚度：无限厚X-raytubetosollerslit(collimator)分析层(饱和厚度)大于饱和厚度的样品称为无限厚样品SampleFolie.4©2001BrukerAXSAllRightsReserved分析层的厚度：无限厚SampleBKA1(0,18keV)SnLA1(3,4keV)CrKA1(5,4keV)SnKA1(25,2keV)tubetosollerslit样品是否无限厚:取决于所分析的特征谱线Folie.5©2001BrukerAXSAllRightsReserved分析层的厚度：无限厚LineEnergyGraphiteGlassIronLeadCdKA123,17keV14,46cm8,20mm0,70mm77,30mMoKA117,486,063,600,3136,70CuKA18,055,51mm0,3836,40m20,00NiKA17,484,390,3129,8016,60FeKA16,402,720,20*164,0011,10CrKA15,411,620,12104,007,23SKA12,31116,00m14,80m10,104,83MgKA11,2520,007,081,921,13FKA10,683,701,710,360,26NKA10,390,831,110,080,07CKA10,28*13,600,420,030,03BKA10,184,190,130,010,010,01m=10nm=100Aatomradius:0,5-3AFolie.6©2001BrukerAXSAllRightsReservedtube分析层的厚度：对于轻基体（如液体）Lightmatrix什么时候要考虑样品的无限厚问题：轻基体中测量重元素样品量很少解决方法：制样时需称样将样品的重量输入软件中，软件会自动校正样品厚度不同带来的影响Folie.7©2001BrukerAXSAllRightsReservedX射线荧光光谱可以分析的样品种类固体，块状样品金属块矿石块粉末状样品压片法添加处理熔融样品熔剂坩埚液体样品优势与不足Folie.8©2001BrukerAXSAllRightsReserved块状样品的制样方法对于金属样品研磨研磨+抛光（分析轻元素时需要）需要考虑样品加工时带来的污染，如SiO2、Al2O3基体效应教严重，不过采用新的软件，可以对基体效应进行校正Folie.9©2001BrukerAXSAllRightsReserved块状样品的制样方法对于矿样考虑到样品的不均匀性，一般先制成粉末也可以直接进行定性或半定量分析Folie.10©2001BrukerAXSAllRightsReserved块状样品的制样方法块状样品制样要求：光洁度方向角度块状样品缺点：均匀性方法适用性一致性Folie.11©2001BrukerAXSAllRightsReserved粉末样品的制样方法直接装入液体杯中测量，称为松散样品压片制样特点：简单、快速、节省存在颗粒效应、矿物效应添加处理类型与作用标准添加；基体添加；次要元素；内标；稀释（低吸收、高吸收、研磨剂）Folie.12©2001BrukerAXSAllRightsReserved松散样品NatoUabsorptioninfoilHeflushingrequired?forqualitativeandsemiquantitativeanalysisforquantitativeanalysisinspecialcasesonly（一般是压不成片的时候）Folie.13©2001BrukerAXSAllRightsReserved压片制样不加粘结剂直接压片以硼酸、低压聚乙烯、纤维素等镶边垫底以硼酸垫底压至钢环中压至铝杯中加粘结剂黄蜡粉(CandH)硼酸(B,HandO)纤维素硬脂酸，如分析炭素Folie.14©2001BrukerAXSAllRightsReserved压片制样的精密度compoundCaOSiO2Fe2O3MgONa2Otypicalconcentration(%)4520210.2typicalintensity(kCountsin40s)600040002000305countingstatistics(%abs.)0.0180.010.00150.0060.003countingstatistics&instrumentprecision(%abs.)0.030.020.0040.010.005multiplesamplepreparation(%abs.)0.20.10.020.050.02typicalaccuracy(%abs.)0.20.20.050.050.03preparedaspressedpowdersFolie.15©2001BrukerAXSAllRightsReserved熔融制样熔融设备（最高温度1100℃）马弗炉燃气炉高频炉熔剂四硼酸锂Li2B4O7偏硼酸锂LiBO2Li2B4O7和LiBO2的混合物如12：22铂黄坩埚（95％Pt+5%Au)(坩埚和模子)Folie.16©2001BrukerAXSAllRightsReserved熔融制样方法：常用熔剂Li2B4O7（熔点：920oC）LiBO2（熔点：850oC）Li2B4O7+LiBO2：混合熔剂如12：22常用的熔融比：1：5，1：10，1：20脱模剂（改变熔液的浸润特性，以方便脱模）LiBrKINH4IKBr氧化剂NaNO3NH4NO3LiNO3Folie.17©2001BrukerAXSAllRightsReserved熔融制样方法：典型的熔融方法铁矿制样熔融制样方法5gLi2B4O7+0.5样品+1mLLiBr(30mg/mL)+1mLLiNO3(220mg/mL)电炉上烘干10min1100C熔融10min冷却成型Folie.18©2001BrukerAXSAllRightsReserved熔融制样优点消除化学态效应消除颗粒效应消除吸收-增强效应便于保存熔剂四硼酸锂Li2B4O7偏硼酸锂LiBO2Li2B4O7和LiBO2的混合物如12：22铂黄坩埚（95％Pt+5%Au)(坩埚和模子)注意事项？1、熔剂选择2、坩埚选择Folie.19©2001BrukerAXSAllRightsReserved压片制样与熔融制样的比较例子：水泥生料样品6个标准样品制样方法熔融制样0.9g样品8.1g熔剂压片制样加20%的黄蜡粉作为粘结剂Folie.20©2001BrukerAXSAllRightsReserved压片制样与熔融制样的比较例子：水泥生料成分含量范围%制样方法校准曲线的标准偏差%灵敏度Kcps/%LLD(100s,3)ppmNa2O0.04–0.6熔融制样0.030.970压片制样0.03614MgO0.5–2.1熔融制样0.021.730压片制样0.157.212Al2O32.0–3.7熔融制样0.041.617压片制样0.18.75SiO212–17熔融制样0.22.3-压片制样29.2-P2O50.03–0.2熔融制样0.0021.715压片制样0.0066.15Folie.21©2001BrukerAXSAllRightsReserved压片制样和熔融制样的分析结果的比较成分含量范围%制样方法校准曲线的标准偏差%灵敏度Kcps/%LLD(100s,3)ppmK2O0.02–1熔融制样0.046.39压片制样0.05283CaO41–47熔融制样0.37.3-压片制样1.222TiO20.10–0.21熔融制样0.0057.17压片制样0.007115Mn2O30.02–0.10熔融制样0.001138压片制样0.001204Fe2O30.43–2.8熔融制样0.02267压片制样0.03452Folie.22©2001BrukerAXSAllRightsReserved液体样品水,油,溶液,泥浆,...尽量不要分析对仪器有腐蚀或污染的样品，如酸溶液Folie.23©2001BrukerAXSAllRightsReserved液体样品：用液体杯直接分析不同的样品要选择合适的膜光路为氦气光路，千万不要抽真空Folie.24©2001BrukerAXSAllRightsReserved液体样品可以分析的元素范围:Na-UFolie.25©2001BrukerAXSAllRightsReservedWD-XRFMginOil:0-900ppmFolie.26©2001BrukerAXSAllRightsReservedWD-XRFMginOil:0-900ppmFolie.27©2001BrukerAXSAllRightsReserved油品样品中各元素的检出限ElementConcentrationRangeppmCalibrationStdDevppmLLD100s3ppmNa0-500109Mg0-50033.5Al0-50022Si0-50022P0-2500101S0-6000101Cl0-50042Ca0-500151Ti0-90021V0-50030.8Cr0-50020.8Mn0-50020.7Fe0-50020.8Ni0-90020.6Cu0–120010.5Sn0-50053Pb0-50021Folie.28©2001BrukerAXSAllRightsReserved液体样品：滤纸片法smallquantitiesofsample(several100µl)droppedonafilterpaperwithanhydro-phobicringtoguaranteeaconstantareaoverwhichthesampleisspreadunloadedfiltersnecessaryforblankmeasurementFolie.29©2001BrukerAXSAllRightsReserved液态样品优点消除颗粒效应消除异型限制适用性限制破坏性溶剂选择保存与操作信号消弱注意事项？1、X射线照射时间2、试剂保存Folie.30©2001BrukerAXSAllRightsReserved章节总结：X射线类型与特征X射线荧光产生X射线荧光分析的应用特点X射线荧光仪器结构与主要部件X射线荧光分析方法基体效应样品制备与要求Folie.31©2001BrukerAXSAllRightsReserved讨论：X射线荧光的原理与分析应用要求：PPT8-10min；X射线原理（基础原理）；X射线应用分析；应用范例（2-3个），包括制样-分析方法-谱图解析-结果表述学生8左右（自由组合；或按顺序安排）