Continuous solid-phase extraction and dansylation of low-molecular-mass amines coupled on-line with liquid chromatography and peroxyoxalate chemiluminescence-based detection

Abstract

An on-line liquid chromatographic system involving solid-phase extraction, dansylation and peroxyoxalate chemiluminescence-based detection was used to determine low-molecular-mass amines in environmental water samples. Sample volumes of 50 ml were enriched in the amines by passage through an IRC-50 cation-exchange column, elution and on-line derivatization with 0.16 M borate buffer (pH 11) and dansyl chloride, respectively, to a C 18 analytical column, and determined by using an integrated derivatization-chemiluminescence detection unit based on the bis(2,4,6-trichlorophenyl)oxalate–hydrogen peroxide system. Dynamic ranges from 60 ng l −1 to 400 μg l −1, limits of detection at the nanogram-per-litre level and relative standard deviations from 2.2 to 5.0% were thus obtained for the amines. The proposed method surpasses other chromatographic alternatives based on different detection techniques in terms of limits of detection. Also, it affords routine analyses of environmental waters containing low-molecular-mass amines at trace levels.