A Novel Hydride Generation and Gas-Liquid Separation Device for Determination of Trace Zinc by Atomic Fluorescence Spectrometry

Abstract

Due to the easy decomposition of zinc volatile species under ambient conditions, delayed gas-liquid separation or shortened transport paths in its hydride generation (HG) could result in decreased sensitivity and reproducibility in atomic spectrometric detection. Therefore, a new HG sampling device was designed to improve the detectability of trace zinc by coupling with atomic fluorescence spectrometry (AFS). The new device can realize hydride generation and the rapid gas-liquid separation simultaneously, and effectively shorted the transport path/time to the AFS, so as to obtain better analytical performance for zinc determination. Moreover, the addition of the modifier sodium diethyldithiocarbamate (DDTC) and Co2+ enhanced the detection sensitivity of zinc. Under the selected experimental conditions, the limit of detection (LOD) of Zn was 0.1 μg L-1, the relative standard deviation (RSD) was 3.0% with zinc concentration of 10 μg L-1, and the linear dynamic ranges was 1-200 μg L-1 (R2 = 0.999). The sensitivity and LOD are greatly improved, in comparison with those of the conventional HG-AFS for zinc.