氢化物发生-原子荧光光谱法测定铁鳞中砷和汞

摘要

A new method has been developed for the determination of arsenic and mercury in mill scale by hydride generation atomic fluorescence spectrometry. The samples were digested by HC1 (1 + 1), and arsenic and mercury in sample were determined by hydride generation atomic fluorescence spectrometry with addition of thiourea-ascorbic acid mixed solution as reductant and masking reagent. The influencing factors were investigated, including the sample acidity, thiourea-ascorbic acid concentration, reduction time, potassium borohydride concentration, carrier and matrix effect, and the optimal determination conditions were obtained. The detection limits of the method for As and Hg were 0. 036 μg/g and 0. 010 μg/g, respectively. The relative standard deviations were 5. 1% and 8. 8%, respectively (n=ll, As 1 μg/g, Hg 0. 2 μg/g ) , and the recoveries were in the range of 95%-l10%.%建立了氢化物发生-原子荧光光谱法同时测定铁鳞中砷和汞的新方法.样品采用盐酸(1+1)分解,加入硫脲-抗坏血酸混合溶液作为还原剂和掩蔽试剂,以氢化物发生-原子荧光光谱法进行检测.详细研究了样品酸度、硫脲-抗坏血酸浓度、还原时间、硼氢化钾浓度、载流、基体效应等因素对测定结果的影响,并确定了最佳检测条件.本方法砷和汞的检出限分别为0.036 μg/g和0.010 μg/g;相对标准偏差(RSD)分别为5.1％和8.8％(n=11,As为1 μg/g,Hg为0.2μg/g),回收率介于95％～110％之间.