On-line microwave-assisted sample decomposition for lead determination in fish slurry samples by electrothermal atomic absorption spectrometry

Abstract

An on-line microwave-assisted decomposition procedure for the determination of lead in fish is proposed. 300 µL slurry and 400 µL of a 6 mol L-1 HNO3 solution were simultaneously injected, and the mixture was positioned inside a microwave oven. The decomposed sample inside the flushing solution was collected in the autosampler cup of a graphite furnace. The proposed procedure covered the 2.5 to 25 µg L-1 Pb range and presented a detection limit of 0.72 µg L-1 Pb. Precision expressed as RSD, was 10.5% (n = 20) for repeatability and 14.3% (n = 10) for reproducibility. Accuracy was assessed using standard reference material, and also by comparing the results to a nitric-perchloric decomposition procedure.