高压消解-双道氢化物发生-原子荧光光谱法同时测定苦丁茶原植物中的砷和汞

Simultaneous Determination of Arsenic and Mercury in Kudingcha Original Plants by HG-DCAFS with High Pressure Digestion

采用HNO3/H2SO4预消解、HNO3/H2O2高压消解,硫脲-抗坏血酸预还原等手段,建立了高压消解-双道氢化物发生-原子荧光光谱同时测定苦丁茶原植物中砷和汞含量的分析方法。讨论并优化了分析测定条件,结果表明,砷和汞的线性范围分别为1.0×10-3—11.0×10-3mg.L-1和1.0×10-4—10.0×10-4mg.L-1,相关系数r分别为0.9986、0.9970,检出限分别是4.73×10-5mg.L-1和8.70×10-6mg.L-1;相对标准偏差(n=6)砷不大于4.25%,汞不大于4.92%。应用于5种苦丁茶原植物砷和汞含量的测定,该方法操作性强、用时短、灵敏度高。

The analytical method for the simultaneous determination of the contents of arsenic and mercury in kudingcha original plants were established by hydride generation-double channel atomic fluorescence spectrometry（HG-DCAFS） with high pressure digestion.The samples were treated by the mixed-acid of sulfuric acid and nitric acid that used as pretreatment oxidant.Then the samples were treated with the mixed-acid of nitric acid and hydrogen peroxide that used as high pressure digestion,and that were treated to prereduction by sulfourea-ascorbic acid.The analytical conditions were discussed and optimized,and the linear ranges of arsenic and mercury were 1.0×10-3—11.0×10-3mg·L-1 and 1.0×10-4—10.0×10-4mg·L-1,with correlation coefficients of 0.9986 and 0.9970,respectively.The parallel determination was done for 6 times and the relative standard deviations were not more than 4.25% and 4.92%,respectively.The detection limits of arsenic and mercury were 4.73×10-5mg·L-1 and 8.70×10-6mg·L-1,respectively.The method is easy to operate and needs short time with high accurate for determination of arsenic and mercury in the five samples.