微波消解-原子荧光-标准加入法测定硫磺中微量砷含量

本着减少环境污染、提高工作效率，建立了一种操作简单、准确测定硫磺中微量砷的微波消解．原子荧光．标准加入法。采用HNO，对硫磺进行微波消解，功率经过14min达到600W并保持20min；光电倍增管负高压为280V，灯电流为80mA，原子化器高度为8mm，载气流量为300mL／min，屏蔽气流量为800ml/min；采用标准加入法对样品中微量砷进行定量。结果表明，砷的线性范围为：0．25～15μg/L（r=0．9999），检出限为：0．03ug／L，加标平均回收率为99．6％（RSD≤1．8％）。与用于硫磺中砷含量测定的二乙基二硫代氨基甲酸银分光光度法（Ag．DDC）相比较．微波消解-原子荧光-标准加入法具有样品用量少、所需试剂种类少、无环境污染、操作简单、灵敏度高、测量数据准确等优点，适合硫磺中微量砷含量的检测。

Determination of micro arsenic in sulfur by microwave digestion-atomic fluorescence spectrophotometer-standard addition method

With the purpose of environment pollution reducing,a rapid and accurate method for the deter- mination of micro arsenic in sulfur by microwave digestion-atomic fluorescence spectrophotometer-standard addition method has been established. The samples were processed by microwave digestion with HNO3 as digestion reagent,and the digestion power was risen to 600 W by 14 min ,and 600 W keeping 20 min. The detections were done at 280 V ,80 mA,8 mm,300 mL/min and 800 mL/min. The standard addition method was used for the quantitative detection of micro arsenic. The result showed that the linear range of arsenic was 0.25 - 15 μg/L （ r = 0.999 9 ）. The detection limit of arsenic was 0.03 μg/L. The average re- cover）, was 99.6% （ RSD ≤ 1.8% ）. Compared with Ag-DDC, microwave digestion-atomic fluorescence spectrophotometer-standard addition method is less samples and reagents, non pollution, easy operation, rapid, reproducible and accurate. It can be used for the determination of micro arsenic in sulfur.