微波消解—原子荧光光谱法测定果汁中的痕量砷

Determination of Trace Arsenic in Fruit Juice by Method of Microwave Digestion-Atomic Fluorescence Spectrometry

建立微波消解-原子荧光光谱法测定果汁中痕量砷的方法。试验采用硝酸、过氧化氢微波消解样品，用体积分数为3％的盐酸作载流，质量浓度为10g／L的硼氢化钾作还原剂测定样品中的砷。对负高压、灯电流、载气流量、屏蔽气流量等进行考察并优化。结果显示：砷标准溶液在0—10．0μg／L质量浓度范围内与荧光强度值有良好的相关关系，相关系数为0．9998，标准物质测定值和标准值相吻合，加标回收率在90．9％～107．1％。该法具有低检出限、高精密度和良好的重现性等特点。

An method was established that the microwave digestion-atomic fluorescence spectrometry was used to determinate the content of trace arsenic in fruit juice. The arsenic in the sample was measured using nitric acid and hydrogen peroxide as the microwave digestion samples, hydrochloric acid of volume fraction of 3% as the carrier stream and potassium borohydride of 10 g/L as reducing agent. The negative high voltage, lamp current, carrier gas flow, shielding gas flow were studied and optimized. The results showed that the arsenic staadard solution within the concentration range of 0-10.0μg/L had high correlation with the fluorescence intensity values, the correlation coefficients was 0.999 8, the measured standard material values coincided with the standard values and the recovery of standard addition was between 90.9%-107.1%. This method has a low detection limit, high precision and good reproducibility characteristics.