碘化物升华分离-电感耦合等离子体光谱法测定土壤和沉积物中砷、锑、铋、镉、锡

将土壤或水系沉积物样品与固体NH4I按1:0·25的比例在双球玻璃管中混匀后在苯灯喷焰上加热,使样品中的As,Sb,Bi,Cd和Sn转变为碘化物升华逸出而与基体分离,挥发物用盐酸溶解后用电感耦合等离子体光谱法(ICP-AES)测定。实验探讨了NH4I的用量、挥发和溶解条件,光谱测定条件,内标选择,测定谱线选择及背景和谱线干扰校正。用土壤和水系沉积物国家一级标准物质验证了方法的准确性和精密度,测定结果与标准值吻合。方法快速简便,结果可靠,检出限为0·01～0·35μg·g-1,适用于地球化学勘探大批量土壤和沉积物样品中As,Sb,Bi,Cd和Sn的测定。

Determination of As,Sb,Bi,Cd and Sn in Soils and Sediments by Inductively Coupled Plasma Atomic Emission Spectrometry after Sublimation Separation as Iodides

A method was developed for the determination of As, Sb, Bi, Cd and Sn in degrees C, iodides of As, Sb, Bi, Cd and Sn were formed and sublimated from the sample matrix and then extracted by diluted HCl. The prepared solution was determined by ICP-AES. The sample treatment procedure, such as the ratio of NH4 I to sample, and sublimation and extraction conditions, was studied. The instrument determination parameters, including ICP power, Ar gas flow rate, spectral wavelengths, background subtraction, spectral interferences correction and internal standard, were selected and optimized. The established procedure is rapid and simple, the detection limits for the five elements are in the range of 0.01-0.35 microg x g(-1), and the analytical results for soil and sediment reference materials were in good agreement with the reference values.