부산대학교 도서관

Two different polymeric resins, one of them based on hydroxyethylmethacrylate (HEMA), and the other on polystyrene-divinylbenzene (PS-DVB), both containing quaternary ammonium groups, have been tested for solid phase extraction of chlorophenoxy acid herbicides. Retention and elution performance in off-line and on-line mode for 2,4-D, 2,4-DB, 2,4-DP, 2,4,5-T, 2,4,5-TP, and MCPA have been studied and compared. Higher and more reproducible recoveries were obtained with the two sorbents in on-line operation, those being for 100 mL of water samples higher than 92% for the based HEMA polymer and 85% for PS-DVB. Reproducibility, expressed as relative standard deviation, was between 1.3 and 6.7% (n=5). Breakthrough volumes, pH effect, and retention capacity for these compounds has also been studied. The effect of complex polar matrices in the retention-elution process was studied by spiking the phenoxy acid herbicides in pear samples. The extracted chlorophenoxy acids were determined in all cases by liquid chromatography with UV detection. [ABSTRACT FROM AUTHOR]