A novel hydride generation and gas–liquid separation device for the determination of trace zinc by atomic fluorescence spectrometry

Abstract

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