Enantioselective analysis of glufosinate using precolumn derivatization with (+)-1-(9-fluorenyl)ethyl chloroformate and reversed-phase liquid chromatography

We have developed a new analytical method to quantify the dl-homoalanine-4-yl(methyl)phosphinate (dl-GLUF) enantiomers in biological specimens using a reversed-phase high-performance liquid chromatography system with a fluorescence detection system. The derivatization of dl-GLUF enantiomers with (+)-1-(9-fluorenyl)ethyl chloroformate was carried out under mild conditions (40 °C for 30 min) without inducing racemization. The lower limit of quantitation was 0.01 μg/ml for both d-GLUF and l-GLUF, and the detection limit was 5 ng/ml. When dl-GLUF enantiomers were added to serum to produce concentrations between 0.1 and 100 μg/ml, the mean recovery rate was at least 93.8%. The recovery rate from urine was also satisfactory.