Assay for histidine decarboxylase in rat stomach and brain by high-performance liquid chromatography with fluorescence detection

Determination of agmatine, arginine, citrulline and ornithine by reversed-phase liquid chromatography using automated pre-column derivatization with o-phthalaldehyde

A method is presented for the pre-column derivatization of agmatine, arginine, citrulline or ornithine with o-phthalaldehyde-2-mercaptoethanol, and subsequent separation of the derivatives by reversed-phase liquid chromatography. Fluorescent response is linear from 10 to 150 pmol of injected analyte and detection limits range from 28 to 100 fmol. Response factors relative to the internal standard, homocysteic acid, were 1.16 (agmatine and arginine), 1.03 (citrulline) and 0.34 (ornithine). The applicability of the method to the measurement of arginase, arginine deaminase, arginine decarboxylase and other enzyme activities in bacterial extracts was examined.