X射线荧光光谱法同时测定土壤和水系沉积物中23种主次痕量组分

Simultaneous Determination of 23 Major,Minor and Trace Components in Soil and Stream Sediment by X-Ray Fluorescence Spectrometry

提出了X射线荧光光谱法(XRF)同时测定土壤和水系沉积物中Br、Cl、Al_(2)O_(3)、CaO、Cr、Cu、Fe_(2)O_(3)、Ga、K_(2)O、MgO、Mn、Na_(2)O、Nb、Ni、P、Pb、Rb、SiO_(2)、Ti、Zn、Zr、V、Y等23种主次痕量组分的方法。利用粉末压样机将样品压制成圆形样片后,按照仪器工作条件进行测定。以120个国家标准物质为校准样品绘制校准曲线,采用经验系数法和康普顿散射内标法校正基体效应,研究了Pb对Ga、Br测定结果的影响。结果表明:高含量Pb会对Ga、Br产生谱线重叠干扰,因此选择Pb为Ga、Br谱线重叠干扰的校正元素,并将Br的校正系数由负值-0.000 48调整为正值0.000 48;23种组分检出限为1~1 000μg·g^(-1);以两个未参与曲线校正的土壤和水系沉积物标准物质进行方法验证,所得测定值与认定值基本一致,测定值的相对标准偏差(n=12)均小于10%,符合DZ/T 0258-2014要求。

A method for the determination of 23 major,minor and trace components,including Br,Cl,Al_(2)O_(3),CaO,Cr,Cu,Fe_(2)O_(3),Ga,K_(2)O,MgO,Mn,Na_(2)O,Nb,Ni,P,Pb,Rb,SiO_(2),Ti,Zn,Zr,V and Y,in soil and stream sediment by X-ray fluorescence spectrometry(XRF) was proposed.The powder press machine was used to press the sample into circule,and the test was carried out according to the working condition of the instrument.Calibration curves were drawn with 120 national reference materials as calibration samples.Empirical coefficient method and Compton scattering internal standard method were used to correct matrix effect,and the effect of Pb on the determined results of Ga and Br was studied.It was shown that high content of Pb would have spectral line overlap interference on Ga and Br,so Pb was selected as the correction element of spectral line overlap interference for Ga and Br,and the correction coefficient of Br was adjusted from negative value-0.000 48 to positive value 0.000 48.The detection limits of 23 components were in the range of 1-1 000 μg·g^(-1).Two soil and stream sediment reference materials,that were not involved in curve correction,were used to verify the method.The determined values were basically consistent with the certified values,and RSDs(n=12) of the determined values were less than 10%,meeting the requirements of DZ/T 0258-2014.