Determination of As in tobacco by using electrochemical hydride generation at a Nafion® solid polymer electrolyte cell hyphenated with atomic fluorescence spectrometry

In the present work, a novel solid polymer electrolyte hydride generation (SPE-HG) cell was developed. The home-made SPE-HG cell, mainly composed of three components (Nafion®117 membrane for separating and H+ exchanging, a soft graphite felt cathode and a Ti mesh modified by Ir anode), was employed for detecting As by coupling to atomic fluorescence spectrometry (AFS). The H+ generated by electrolysis of pure water in anode chamber transferred to cathode chamber through SPE, and immediately reacted with As3 + to generate AsH3. The relative mechanisms and operation conditions for hydride generation of As were investigated in detail. The developed cell employed water as an alternative of acid anolyte, with virtues of low-cost, more than 6 months lifetime and environment friendly compared with the conventional cell. Under the optimized conditions, the limit of determination of As3 + for sample blank solution was 0.12 μg L− 1, the RSD was 2.9% for 10 consecutive measurements of 5 μg L− 1 As3 + standard solution. The accuracy of the method was verified by the determination of As in the reference Tea (GBW07605) and the developed method was successfully applied to determine trace amounts of As in tobacco samples with recovery from 97% to 103%.