Nonaqueous capillary electrophoretic separation and thermo-optical absorbance detection of five tricyclic antidepressants and metabolism of amitriptyline by Cunninghamella elegans

We developed a technique based on nonaqueous capillary electrophoresis and laser-based thermo-optical absorbance detection to assay five antidepressan ts with similar structures and mass-to-charge ratios. A mixture of methanol and acetonitrile with ammonium acetate was essential to achieve baseline r esolution of these compounds. We investigated the effects of ammonium aceta te concentration, temperature, applied voltage, and capillary length on sep aration efficiency. The nonaqueous capillary electrophoresis and laser-base d thermo-optical absorbance detection technique was used to study the metab olism of amitriptyline by Cunninghamella elegans. Sample preparation proced ures were simplified for fast screening of the parent drug and its metaboli tes. Reproducible electropherograms were obtained from replicate cultures o f C. elegans growing in the presence of amitriptyline.