康普顿散射线结合经验系数法校正在X射线荧光光谱测定石灰石和白云石中的应用

Application of Compton scatter and empirical coefficient correction in X-ray fluorescence spectrometric determination of limestone and dolomite

石灰石、白云石样品与混合熔剂（Li2B4O7-LiBO2-LiBr）稀释比为1：8，硝酸锂做氧化剂、950℃熔融20min制备玻璃片，应用X射线荧光光谱法（XRF）测定石灰石、白云石中氧化钙、氧化镁、二氧化硅、三氧化二铝、三氧化二铁、氧化锰、磷、硫、二氧化钛、氧化锶、氧化钾和氧化钠12种组分。通过标准样品、光谱纯物质、标准样品与标准溶液合成样品及化学定值样品制作校准曲线并进行分段回归。应用康普顿散射线校正铁、锰、锶元素，经验系数法校正其他9种元素，可有效克服石灰石、白云石中各组分测定时基体效应的影响。对样品进行精密度考察，各组分测定结果的相对标准偏差（RSD，n=10）在0．18％～11．4％之间。对标准样品及未知样品进行正确度考察，测定值与认定值或湿法值一致。

A fusion sample preparation technique has been developed with mixed flux （Li2B40T-LiBO2-LiBr） by using a 1 ~ 8 dilution ratio at 950 ℃ and fusion for 20 minutes. The contents of twelve components in limestone and dolomite including CaO, MgO, SiO2, Al2O3, Fe2O3, MnO, P, S, TiO2, SrO, K2O and Na2O were determined by X-ray fluorescence spectrometry（XRF）. Calibration curves were carried out and fitted for the concentration subsection with limestone and dolomite certified reference materials, spectrum pure reagents, synthetic samples prepared with certified reference materials and standard solution, and chemical certified materials. The matrix effect in limestone and dolomite was corrected by applying Comp- ton scatter for element Mn, Fe, Sr and using empirical coefficient methed for the other nine elements. The precision experiment was performed with limestone and dolomite sample. The relative standard deviation （RSD, n=10） was 0.18%-11. 4%. The accuracy test was conducted with certified reference material and unknown sample. The results were consistent with the certified values and those obtained by wet method.