A simple and fast approach for the determination of inorganic and total mercury in aqueous slurries of biological samples using cold vapor atomic absorption spectrometry and in situoxidation

Abstract

A simple, fast and reliable method for the determination of inorganic and total mercury in biological samples directly from slurries prepared in water has been developed using cold vapor atomic absorption spectrometry. The method does not require any standing time or heating of the slurries. Samples are simply mixed with water and measurement can be carried out immediately. For inorganic mercury determination, no additional preparation is required. For total mercury determination the samples have to be oxidized previously with a 2% m/v KMnO₄ solution for 2 minutes. After that, the measurement can be carried out similarly to that for inorganic mercury determination. The methylmercury concentration can be calculated as the difference between total and inorganic mercury. The greatest advantage of this method is that only a minimum of reagents and sample handling steps are required, which stands as a prerequisite for accurate results in routine analysis, particularly for the determination of mercury. The results were in good agreement with the 95% confidence level of the certified or close to the informed value for the reference materials investigated. The relative standard deviation was better than 7% for most of the samples. The limits of detection in the sample were determined as 0.020 and 0.016 µg g⁻¹ for inorganic and total mercury, respectively.