Mercury determination -: SPME and colorimetric spot test

A colorimetric method to determine mercury > 20 ng (absolute) in eluates of soils, wastes and waste water was developed. For the elution and the analytical determination only 40 min are needed and the determination can be carried out on site. Due to the low Austrian and German regulatory limit levels of mercury (0.01 mg/1000 g solid phase) it needs to be enriched three times before such low concentrations can be detected. This is done by means of SPME (solid phase micro extraction: Z. Zhang, M.J. Yang, J. Pawliszyn, Anal. Chem. 66 (17) (1994) 844; C.L. Arthur, L.M. Killam, S. Motlagh, M. Lim, D.W. Potter, J. Pawliszyn, Environ. Sci. Technol. 26 (1992) 979; R. Eisert, K. Levsen, J. Chromatogr. A 733 (1996) 143), liquid-liquid extraction and by concentrating the coloured mercury complex in a dot on a TLC-plate. This method was developed as a field method for monitoring set limit levels on site. The interference of non-analytes was determined by adding non-analytes to standard solutions. Mercury contents in soil samples were determined with the developed SPME-spot test and by a standardised method (cold vapour atomic absorption spectrometry). Results were comparable. (C) 2001 Elsevier Science B.V. All rights reserved.