预还原氢化物发生—原子荧光光谱法快速测定化探样品中的As,Sb,Bi,Hg

通过对化探样品进行王水密闭溶解,饱和的硫脲-抗坏血酸预还原,运用氢化物发生-原子荧光光谱法实现了地质样品中As、Sb、Bi、Hg元素的任意配对以及连续快速测定。实验确定了原子化器高度为14mm,最佳溶样时间为1h。在优化条件下,结果显示还原剂(硫脲-抗坏血酸)对Hg、Bi测定结果无影响,且Hg、Bi测定结果在预还原20min至48h内都很稳定,测定结果良好,Cu、Co、Ni、Au、Ag、Cd、As、Sb、Bi、Se、Ge等金属离子对预还原测定汞均无干扰,对比实验表明还原剂体系下汞荧光强度值基本不变。方法的检出限低、精密度好、准确度高、操作简便,有效避免了元素污染问题,可满足大批量地质样品分析测定的需要。

Quick determination of As,Sb,Bi,Hg in geochemical samples by prereduction hydride generation-atomic fluorescence spectrometry

The arbitrary matching and continuous rapid determination of As, Sb, Bi, Hg in geochemical samples were achieved through hydride generation-atomic fluorescence spectrometry. The samples were dissolved in sealed vessels with aqua regia and prereduced by saturated thiourea-ascorbic acid. This paper proved that the atomizer height was 14 mm, and the optimum sample-dissolution time was 1 hour. Under the optimized conditions, the results showed that the reducing agent (thiourea-ascorbic acid) had no effect on the determination results of Hg and Bi. When the prereduction time during 20 minutes to 48 hours, determination results of Hg and Bi were stable and excellent. Cu, Co, Ni, Au, Ag, Cd, As, Sb, Bi, Se, Ge and other metal ions had almost no interference on the determination of prereduction Hg. Contrast experiment showed that when the samples were in the reductant system, the fluorescence intensity values of Hg substantially had no change. This method had advantages of low detection limit, high precision and accuracy, simple operation, and also could effectively avoid the problem of elements pollution, which was adapted to the analysis of multitudinous geochemical samples.