原子荧光光谱法测定蔬菜中的微量砷

Determination of Trace Arsenic in Vegetables with Atomic Fluorescence Spectrophotometry

为提高氢化物发生—原子荧光光谱法测定蔬菜中微量砷的准确度,建立断续流动氢化物发生—原子荧光测定法,并讨论硼氢化钾用量、酸介质及其酸度、原子化器温度、载气流量等分析条件对试验结果的影响。试验结果表明,当砷含量为1.0～200.0ug/L时,线性关系良好,检出限为0.08ug/L。以50g/L硫脲—50g/L抗坏血酸为预还原剂,测定了6种蔬菜中的砷含量,加标回收率为91.6%～104.0%,相对标准偏差为1.4%～2.1%。

In order to improve the precision in determining trace arsenic in vegetables with atomic fluorescence spectrophotometry,interrupted flowing hydride generation,or atomic fluorescence spectrophotometry was established and such factors were examined as the amount of used potassium borohydride,acid medium and its acidity,atomizer temperature,and carrier gas flow rate. The experiment results show that when the arsenic amount is at 1.0～200.0 ug/L,linear relation performs well and the detection limit is 0.08 ug/L. The arsenic amounts in six vegetables are determined using 50 g/L sulfourea—50 g/L ascorbic acid as the reducing agents,and the marked recovery rate is 1.6%～104.0%,and the relative standard deviation is 1.4%～2.1%.