Simple and Rapid Method for the Determination of Trace Bismuth in Sulfur Samples by Hydride Generation Atomic Fluorescence Spectrometry With Microwave Digestion

摘要

A new, simple, rapid, and sensitive method was developed for the direct determination of trace bismuth (Bi) in sulfur samples by hydride generation atomic fluorescence spectrometry with microwave digestion in closed Teflon vessels. In the microwave oven, the samples were completely digested in 35 minutes using 3 mL concentrated nitric acid and 1 mL hydrogen peroxide at a pressure of 0.2-1.5 MPa. The analytical parameters, such as argon flow rate, acidity of the medium, the amount of NaBH4 and interfering ions on the recovery of bismuth were investigated. The detection limit (3 sigma) of bismuth was 0.027 mu g L-1. The relative standard deviation (%RSD) for seven replicate measurements of the sulfur samples was 1.43%-2.21% (n = 7); the standard addition recovery was 96.7-106.7%. The proposed method for the determination of bismuth in sulfur samples is simple, accurate, and there is a low risk of environmental contamination.