A simple and robust method for the determination of Hg in environmental samples by slurry sampling cold vapor generation atomic absorption spectrometry is proposed. After reducing the sample particles size to < 50 µm in an agate mortar, two procedures were used in the slurry preparation: either using 6.7% v/v nitric acid only or 10% v/v aqua regia plus 2% v/v hydrofluoric acid medium. Depending on the sample, the slurry concentrations varied from 3.3 to 23 mg mL-1. The mercury cold vapor generated directly from the acidified sample slurry was conducted to quartz T tube, placed in the atomizer of the spectrometer. Eight certified environmental materials were analyzed. By using the conventional calibration against aqueous standard solutions, excellent results were obtained when aqua regia plus hydrofluoric acid was used as the slurry medium. Sediment and coal samples from Santa Catarina, Brazil were also analyzed. The obtained limit of detection was 30 ng g-1. Simplicity, low cost and high efficiency are some of the qualities of the proposed method, making it adequate for routine analysis.
mercury; environmental samples; slurry sampling; cold vapor; atomic absorption spectrometry
