HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC METHOD FOR THE ANALYSIS OF AMINOCARB, MEXACARBATE AND SOME OF THEIR N-METHYLCARBAMATE METABOLITES BY POSTCOLUMN DERIVATIZATION WITH FLUORESCENCE DETECTION

A sensitive and selective high-performance liquid chromatographic meth od with post-column derivatization, using o-phthalaldehyde and 2-merca ptoethanol, is described for the analysis of aminocarb, mexacarbate an d some of their carbamate metabolites. The separation system consisted of an RP-8 OS (10 mu m) 20 cm x 4.6 mm I.D. column, an acetonitrile-w ater mobile system and a reactor for the hydrolysis of analytes from c olumn effluents and fluorophore formation. The fluorophores were detec ted at 230 nm (excitation) and 418 nm (emission). The recoveries of th e carbamates in spiked natural water at 2 and 20 ng/ml fortification l evels ranged from 72.0 to 98.4% with relative standard deviations of 5 .0 to 11.5%. The recoveries for spiked forest soil at 20 and 200 ng/g fortification levels ranged from 74.1 to 97.6% with relative standard deviations of 5.8 to 10.7%. Limits of detection and quantification for all the analytes were 0.1 and 0.4 ng in water and soil, respectively.