CHROMATOGRAPHIC DETERMINATION OF CARBARYL AND OTHER CARBAMATES IN FORMULATIONS AND WATER USING BRIJ-35

ABSTRACT

A micellar liquid chromatographic (MLC) procedure was developed for the determination of carbaryl and other carbamates (carbofuran, desmedipham, methiocarb and propoxur), using a C18 column and UV detection. Optimisation was performed using the anionic surfactant sodium dodecyl sulphate (SDS) and the non-ionic Brij-35. Both surfactants yielded similar selectivities, but Brij-35 gives shorter retention times than SDS and for this reason was preferred to speed up the analysis of the carbamates. In the selected mobile phase (0.07 M of Brij-35), the analysis time was 22 min. The procedure was applied for the determination in commercial pesticide formulations and spiked samples (distilled, tap, reservoir tank, irrigation ditch, sea and waste water). This method proved to be competitive against the EPA reference method, recommended for the determination of some N-methylcarbamates, which uses a gradient of acetonitrile. The results of the pesticide formulations obtained with both methods are in agreement with the concentrations declared by manufacturers.

Keywords:

• Carbamates
• Micellar liquid chromatography
• Brij-35
• SDS
• Formulations and water samples

ACKNOWLEDGMENTS

This work was funded by Project BQU2001-3770 (MCYT), and P1A2000-13 (Bancaixa) provided the research grant of Mayte Gil-Agustí. Devasish Bose and Abhilasha Durgbanshi thank Fundació Universitat Jaume I-Caixa de Castelló for the research grants.