全反射X射线荧光光谱法同时测定复混肥料中钒铬锰铁镍铜锌铅

摘要

样品经硝酸微波消解,以镓为内标,采用全反射X射线荧光光谱法(TXRF)同时测定复混肥料中的钒、铬、锰、铁、镍、铜、锌、铅,方法检出限从铅的1.0 μg/g到钒的7.0 μg/g,精密度(RSD)铬为2.5％,铅为16％,除铅以外,其余元素的RSD均小于10％;方法回收率为80％ ～ 120％,Pb的回收率略低主要是由于化肥中As Kα谱线对Pb Lα谱线的干扰导致测定结果偏低.用TXRF和电感耦合等离子体发射光谱法(ICP -AES)测定不同复混肥料中各元素的含量,经统计检验,两种方法测定结果在95％置信区间内无显著性差异.对于金属元素含量较高的样品,TXRF法测定结果的相对标准偏差小于ICP - AES法.对于不同的复混肥料,在微量、痕量元素检测范围内,TXRF法具有较高的准确度和适用性,仪器使用和维护成本低,方法快速准确.%In this work, gallium was used as an internal standard and V, Cr, Mn, Fe, Ni, Cu, Zn, Pb in compound fertilizers were simultaneously determined by Total Reflection X-ray Fluorescence Spectrometry (TXRF) after microwave digestion with nitric acid. The detection limits of this method range from 1.0 (μg/g for Pb to 7. 0 (μg/g for V. The RSD of all elements were less than 10% , except for Pb, which was 16%. The recoveries were 80% - 120%. The lower recovery of Pb was caused by the interference of the As Ka spectral line with the Pb La spectral line. The results were compared with Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) and there were no statistically significant differences between the two measurements, within a confidence range of 95%. The RSD obtained by TXRF was less than that by ICP-AES for high contents of metallic elements samples. The results for different compound fertilizers show that the TXRF technique is accurate and applicable in the determination of variously metallic elements. It is inexpensive to use and maintain the TXRF. The established method is rapid and accurate.