粉末压片-X射线荧光光谱法测定土壤、水系沉积物和岩石样品中15种稀土元素

摘要

采用粉末样品压片制样,使用波长色散X射线荧光光谱仪对土壤、水系沉积物和岩石样品中15个稀土元素(La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、Y)进行测定.重点探讨了15个稀土元素的测量条件,如分析线、分析晶体,基体效应和谱线重叠干扰校正.使用60余个土壤、水系沉积物和岩石标样建立校准曲线,采用经验系数法和散射线内标法校正基体效应,并用多元回归准确扣除稀土元素谱线重叠干扰.重稀土元素的检出限多在0.2 μg/g以下.对土壤标准样品进行精密度考察,15个稀土元素测量结果的相对标准偏差(RSD,n=10)为0.74％～17％.对土壤、水系沉积物和岩石标准样品进行分析,测定值和认定值一致.%The sample was prepared by powder pressing,and 15 rare earth elements (La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Y) in soil,stream sediment and rock samples were determined by wavelength dispersive X-ray fluorescence spectrometer.The measuring conditions of 15 rare earth elements were investigated,including analytical line,analytical crystal,matrix effect and spectral overlapping interference.More than 60 soil,stream sediment and rock CRMs were used to establish calibration curves.The matrix effect was corrected by empirical coefficient method and scattered rays internal standard method.The spectral overlapping interference of rare earth elements was accurately deducted by multiple regression.The detection limits of heavy rare earth elements were mostly below 0.2 μg/g.Precision test was conducted on soil CRMs.The relative standard deviations (RSD,n=10) of determination results of 15 rare earth elements were 0.74 ％-17 ％.The soil,stream sediment and rock CRMs were analyzed,and the results were consistent with the certified values.