ION-CHROMATOGRAPHIC DETERMINATION OF ANIONS AND CATIONS AT ULTRA-LOW CONCENTRATIONS IN ALPINE SNOW

As part of the international project ALPTRAC the acid deposition at high Alpine sites was investigated. This paper reports on experiences with ion chromatography in the mu g/kg range that was characteristic for the samples, and on the sample contamination and its sources. Particular emphasis is given to a drop of ionic concentration from the first to the second injection drawn from the vials of the automated sampler. This drop was observed at detection ranges of 3 mu S/cm and less and amounted to 17 mu g/kg for sodium, 14 mu g/kg for chloride and 1 to 4 mu g/kg for magnesium, calcium and sulphate.