ANALYSIS OF SMALL VOLUMES OF SOIL SOLUTION BY CAPILLARY ELECTROPHORESIS

Capillary electrophoresis (CE) is suitable for the analysis of cations and anions, including organic acids, in soil solution, In the concent ration range typical for soil solutions, the standard deviation of the linear calibration function is, with the exception of NH4+ and Na+ (a pproximate to 12%), better than 6%, Using drift correction procedures, CE is applicable for routine analysis, The advantage of this analytic al technique is the minimal sample consumption of about 5 to 10 nL per analytical run, which enables new approaches for soil solution collec tion and analysis on a microscale level, As an example, a podzol profi le was covered by a vertical matrix of 6 x 10 microlysimeters (samplin g distance 2 cm), High resolution maps of soil solution chemistry show ed, that, although some solutes had concentrations related to soil hor izons (UV as measure for DOC, SO42-, Al3+), in general there was littl e correlation between the clearly visible soil horizon borders and con centration isolines, For all solutes analyzed even within soil horizon s marked concentration gradients could be observed.