熔融制样-X射线荧光光谱分析法测定钾冰晶石中主次成分

采用熔融法制样,建立了测定化工产品钾冰晶石中氟、铝、钾、钠、氧化铁、氧化钛、氧化镁、氧化钙及硫酸根的X射线荧光光谱(XRF)分析方法。样品的熔融试验发现,以四硼酸锂和偏硼酸锂混合熔剂m(四硼酸锂)∶m(偏硼酸锂)=67∶33]作熔剂,当样品与熔剂的稀释比为1.5∶10,以1滴饱和LiBr溶液为脱模剂,在1 000 ℃下熔融10 min时制样效果最佳。使用理论α系数法和经验系数法相结合的方法对谱线重叠及元素间的吸收增强效应进行校正。在没有国家标准样品的条件下,采用高纯的化学物质按不同比例混合制成的校准样品绘制校准曲线,其线性范围宽。精密度试验结果发现,各组分的相对标准偏差(RSD, n=11)在0.53%~9.8%之间。采用实验方法对钾冰晶石生产样品中上述9种成分进行测定,结果与其他方法测定结果相符。

Determination of major and minor components in elpasolite by X-ray fluorescence spectrometry with fusion sample preparation

A X-ray fluorescence spectrometry for the determination of F, K, Al, Na, Fe₂O₃, TiO₂, MgO, CaO and SO₄^2- in chemical products elpasolite by fusion sample preparation was established. The mixture of lithium tetraborate and lithium metaborate m(Li₂B₄O₇)∶m(LiBO₂)=67∶33] was used as flux. It was showed that the sample obtained was optimal when the sample was fused at 1 000 ℃ for 10 min with the flux at the dilution ratio of 1.5∶10 (sample to flux) and one drop of saturated lithium bromide solution as release agent. The spectral overlap and absorption enhancement effect were calibrated by combining theoretical α coefficient method with empirical coefficient method. Since there was no available national standard sample, the calibration curve was plotted with synthesized standard sample prepared from highly pure chemicals mixed in different ratios, whose linear range was wide. It was found through precision test that the relative standard deviations (RSDs,n=11) of components were 0.53%-9.8%. Nine components in the production sample of elpasolite were determined by experimental method, whose results were consistent with those obtained by other methods.