氢化物发生-原子荧光光谱法测定汾河太原段沉积物中镉

Determination of Cd in Sediments of Taiyuan Fenhe River by Hydride Generation-Atomic Fluorescence Spectrometry

研究了氢化物发生-原子荧光光谱法测定沉积物中痕量镉的适宜条件,考察了镉信号增强剂、常用酸及酸度和还原剂用量对测定的影响,优选了仪器条件。结果表明,镉发生氢化物反应条件为酸性介质;1.5%盐酸作载流,硼氢化钾还原剂浓度为25.0g.L-1,载气流量为500mL·min-1,主阴极灯电流为50—60mA,原子化器高度为16mm,荧光强度较大且稳定。在最佳测定条件下,其线性范围在0—5μg·mL-1,相关系数r>0.9990,最低检出浓度为0.0070ng·L-1,相对标准偏差为2.7%—5.6%,回收率为89.01%—117.0%,用于沉积物中镉的测定,结果令人满意。

The measurement conditions for the determination of trace cadmium in sediments by hydride generation atomic fluorescence spectrometry were optimized. The effect of different acidic medium,the amounts of acid and reducer concentration on the determination of Cd were studied. The instrument working conditions were selected and optimized. The Cd hydride generation happens with weak acidity ,the fluorescence signal is bigger and more stable at the hydrochloric acid concentration of 1.5% ,the reducer concentration of 25.0g · L^-1,the carrier gas flow of 500 mL · min^-1,the main cathode lamp current of 55mA, and with the atomizer height of the 16mm. Under the optimum conditions,the linear range of determination is 0-5μg·mL^-1 with r〉0. 9990 and the detection limit is 0. 0070ng · L^-1. The recovery is 89.01%-117.0% with RSD of 2. 7%-5.6%.