CATION TRACE ANALYSIS OF SNOW AND FIRN SAMPLES FROM HIGH-ALPINE SITES BY ION CHROMATOGRAPHY

Ion chromatography with self-regenerating suppression and conductivity detection was used for the simultaneous determination of Na+, NH4+, K+, Mg2+ and Ca2+ in melted snow samples from high-alpine sites. Concentrations in the samples showed a high variability and were in the range of 0.3 to 800 mu g/kg Samples with concentrations higher than 2 mu g/kg representing summer snow were analyzed using a 100-mu l sample loop. In order to determine the low concentrations in winter snow samples (<2 mu g/kg), preconcentration of 2-ml samples was applied resulting in improved detection limits of 0.1-0.4 mu g/kg depending on the cation.