AUTOMATED INSTRUMENTATION FOR MINIATURIZED DISPLACEMENT ELECTROPHORESIS WITH ON-COLUMN PHOTOMETRIC DETECTION

This paper describes an automated equipment for capillary displacement electrophoresis (isotachophoresis). The equipment employs the advanta ges of a separation channel with a nonuniform cross-section. The syste m works in a closed mode, the analytes are determined as anions in the examined arrangement. The pH gradient is within the range 4.4-11.0, t he total voltage over the separation channel is from 150 V to 900 V at a constant current of 20 mu A or 10 mu A A, respectively. Cetyltrimet hylammoniumbromide and either hydroxypropylcellulose or hydroxypropylm ethylcellulose are used in the leading electrolyte to control the elec troosmotic flow. The reproducibility and the minimum detectable concen trations are determined and calibration curves are measured using a mo del mixture of pi markers and myoglobin as analytes and either low-mol ecular-mass ampholytic buffers or synthetic carrier ampholytes as spac ers. Both Gaussian peaks and the square-wave zones were evaluated.