Solid sampling-graphite furnace atomic absorption spectrometry for Hg monitoring in soils.: Performance as a quantitative and as a screening method

This work explores the potential of solid sampling-graphite furnace atomic absorption spectrometry for the direct determination of Hg in soils. Taking advantage of the high volatility of the analyte when compared with that of most matrix components. and using KMnO4 as the chemical Modifier, a quantitative method was developed, allowing for the fast and reliable determination of Hg in seven different soil certified reference materials. The main features of this method are: a detection limit of 25 ng g (1), RSD values between 3 and 12% and straightforward calibration with aqueous standards, Furthermore. the paper discusses in detail how to transform this quantitative method into a screening method. intended for those situations in which only a binary response (Yes, No) is required (e.g. routine control of, agricultural soils it) the European Community. for which a legal limit of 1.5 mu g g (1) Hg has been established), The screening method proposed permits obtaining an answer in 6-10 min per sample, For this method. a narrow region of unreliability was calculated (1.15 1.95 mu g g(-1)), such that only the samples that fall into this region Should be further analyzed by means of a more precise technique.