土壤中锑的双阳极电化学氢化物发生-原子荧光光谱法测定

Determination of Antimony by Bianode Electrochemical Hydride Generation-Atomic Fluorescence Spectrometry

采用双阳极电化学氢化物发生与原子荧光在线联用测定土壤中的锑含量,其中氢化物发生通过以纯铅为阴极,2根钛丝作阳极的双阳极电解池实现。对电解池工作条件及原子荧光参数进行了优化,最佳工作条件为以0.5mol.L-1硫酸作电解液,流速2.0mL.min-1,阴极电解电流密度0.5A.cm-2。同时以去离子水为进样载流,流速设定为1.5mL.min-1,六通阀进样100μL得到方法检出限为0.91μg.L-1(S/N=3);相对标准偏差(RSD)为1.58%(50μg.L-1,n=11);线性范围为1～300μg.L-1。

A self-made hyphenated system was developed for on-line determination of antimony in soil. This system used a bianode electrolytic cell as a hydride generator coupled to atomic fluorescence spectrometry （AFS）. Pure lead plate was used as the cathode and two titanium wires were used as the bianode of the electrolytic cell. Parameters that might affect the hydride generation efficiency and the fluorescence signal were investigated. Under optimum conditions, viz, 0. 5 mol · L-1 H2SO4 used as electrolytic solution with a flow rate of 2.0 mL · min-· , a cathode current density of 0. 5 A · cm-2 and the flow rate of the deniozed water to transfer the samples to the cathode channel set at 1.5 mL · min-1 The linear range of the calibration curve was 1 -300 μg · L-1 with a detection limit of 0. 91μg· L-1 Sb （S/N = 3 ）. The relative standard deviation（RSD） for 11 repetitive determinations of Sb （ 50 μg · L- 1 ） was 1.58%. The proposed method was applied to the determination of Sb in soil samples with satisfactory results.