Direct atomic absorption determination of mercury in drinking water and urine using a two-step electrothermal atomizer

A new method was developed for the direct electrothermal atomic absorption determination of mercury in drinking water and urine using double vaporization in a two-step atomizer with a purged vaporizer. In this method, a sample is placed in the vaporizer of a two-step atomizer, dried, and vaporized. The sample vapor is transferred to an unheated atomizer cell with a flow of argon and trapped by the inner surface of cell walls. This procedure can be performed repeatedly to preconcentrate mercury in the atomizer cell. Next, a portion of the sample transferred to the inner surface of the atomizer cell is revaporized and atomized by heating the atomizer cell of the two-step atomizer with a purged vaporizer, and the atomic absorption of mercury is measured. It was found that the degree of mercury transfer and trapping is as high as 100% at sufficiently high temperatures of primary vaporization, regardless of the material of the inner surface of the atomizer cell. The detection limits for mercury were 0.24 or 0.024 µg/L for drinking water at a sample volume of 100 µL using a single sample transfer or the procedure repeated ten times, respectively, and 2.0 µg/L for urine at a sample volume of 20 µL and a single sample transfer. The accuracy of the results was confirmed by the analysis of certified mercury samples and samples with known additives.Translated from Zhurnal Analiticheskoi Khimii, Vol. 60, No. 1, 2005, pp. 45–51.Original Russian Text Copyright © 2005 by Vilpan, Grinshtein, Akatov, Gucer.