CAPILLARY ZONE ELECTROPHORESIS OF HUMIC ACIDS

Capillary zone electrophoresis (CZE) was used for the separation of humic acids. The influence of the buffer solution on the separation of a commercial humic acid was studied. The use of an 8 mmol 1(-1) HCl-59.8 mmol 1(-1) L-alanine buffer (pH 3.17) leads to the separation of humic acids into two fractions. The composition and pH of this buffer and some instrumental parameters such as voltage, injection volume and wavelength of detection were optimized and the quality parameters of the method were determined. Two further commercial humic acids were assayed. The one that showed the highest peak signal was used as a reference for the rough quantification of the others.