Determination of mercury in urine by flow-injection cold vapour atomic absorption spectrometry

Abstract

A simple, rapid and accurate method was developed for the determination of total mercury in urine samples. The method uses on-line addition of KMnO 4 after adding a bromate-bromide reagent to the sample to decompose organic mercury compounds to inorganic mercury(II) ions at room temperature, and determines mercury by flow-injection cold vapour atomic absorption spectrometry. The recoveries of five mercury compounds added to urine were studied; with the proposed method the recoveries of all the mercury compounds used were complete. Good agreement with certificate values of urine reference materials was also obtained. The detection limit of the method based on three standard deviations of the blank was 0.1 μg Hg 1 −1 in urine with a 500-μl sample loop, achieving a same throughput of 100 h −1. The calibration graphs were linear up to 30 μg 1 −1 and with a dynamic range up to 100 μg Hg 1 −1. At a concentration of 5 μ Hg 1 −1 in urine, the relative standard deviation was about 2%.