原子荧光光谱法测定粗锌中的砷

建立了测定粗锌中砷含量的原子荧光光谱法。粗锌样品经硝酸溶液(1+1)低温溶解完全以后,在盐酸介质中,用抗坏血酸预还原,以硫脲掩蔽铜、铁、银等杂质元素,砷被硼氢化钾还原为氢化物,用氩气导入原子化器测量。砷测定结果的相对标准偏差为1.5%~3.0%(n=11),加标回收率为98.4%~103.6%。与国家标准测定方法分光光度法测定结果对比,相对偏差为0.1%~2.4%。该法准确、可靠,适用于砷含量在0.005 0%~0.50%之间的粗锌中砷的测定。

Determination of Arsenic in Crude Zinc by Atomic Fluorescence Spectrometry

An atomic fluorescence spectrometry was established to determine arsenic in crude zinc. After dissolved completely in nitric acid solution (1+1) at low temperature, crude zinc samples was reduced by ascorbic acid in hydrochloric acid medium. Elements of impurities such as copper, iron and silver were masked with thiourea, and arsenic was reduced to arsenic hydride by potassium borohydride, measured with argon gas import atomization device, and then the atomic fluorescence spectrometry method was developed. The relative standard deviation was 1.5%-3.0% (n=11), the standard addition recoveries were 98.4%-103.6%. Compared with the national standard analysis method of spectrometry, the relative deviations of the measurement results of arsenic were 0.1%-2.4%. The method is accurate and reliable, and it is suitable for determination of arsenic in crude zinc whose arsenic content between 0.0050% and 0.50%.