Determination of antimony in water samples by hydride generation coupled with atmospheric pressure glow discharge atomic emission spectrometry

Abstract

A low power (∼10 W), miniaturized atmospheric pressure glow discharge (APGD) source sustained between a tungsten cathode and a titanium tube anode was coupled with a hydride generation (HG) system for sensitive determination of antimony in water samples with atomic emission spectrometry (AES). Sb ions were converted into volatile hydrides through the reaction with KBH₄ firstly and then were introduced into the APGD source for excitation and detected using a compact CCD (charge-coupled device) microspectrometer. A univariate approach was used to achieve optimized conditions and derive analytical figures of merit. Under optimal conditions, the limits of detection and quantification for Sb were 0.14 and 0.5 μg L⁻¹, respectively. Moreover, the HG-APGD-AES system offered good repeatability (relative standard deviation < 1.5%). The calibration curve was linear in the range between 0.5 and 100 μg L⁻¹, with a correlation coefficient of R² = 0.9996. The proposed method was successfully applied to the determination of certified reference materials (GSB 07-1376-2001, GBW07305a, GBW07307a and GBW073066) and some groundwater samples. Recoveries of Sb added to these water samples were within 90.9–100.7%, proving the good accuracy of the HG-APGD-AES method.