High Sensitivity Determination of Antimony with Application for the Characterization of Its Migration in Bottled Water by a Dielectric Barrier Discharge (DBD) Coupled with Hydride Generation – Atomic Fluorescence Spectrometry (HG-AFS)

Abstract

An in situ dielectric barrier discharge (DBD) employed as a preconcentration device was coupled with hydride generation atomic fluorescence spectrometry (HG-AFS) for the determination of antimony (Sb) that migrated from plastic to bottle water. In the presence of oxygen under a 7.5 kV discharge, Sb was completely trapped on the surface of dielectric barrier discharge quartz tube. After 50 s of Ar carrier sweeping, water vapor interference was effectively eliminated and Sb was rapidly released by a discharge containing hydrogen using 6.8 kV. In addition, the investigation of Sb migration from bottle materials to water was carried out considering temperature and bottle materials. Under the optimized conditions, the detection of limit (LOD) was 9 pg or 5 pg/mL. The linearity of the calibration relationship R2 exceeded 0.996 for concentrations from of 0.05 to 50 μg/L. In addition, the determined Sb levels of water certified reference materials (CRMs) were in good agreement with the certified values. The spiked recoveries for bottled water samples were from 95% to 104% with 3% to 8% relative standard deviation values. In comparison, the HG-in situ DBD-AFS method is capable to increase the analytical sensitivity using the peak height by 7-fold compared to standard HG-AFS. DBD offers gas phase enrichment at room temperature with instrumental miniaturization for elemental analysis with low energy consumption, small size and low cost.