A liquid chromatographic method using gradient elution and diode array UV detection for the trace level determination of seven synthetic pyrethroids is described. The procedure involves automated on-line preconcentration on precolumns containing octadecylbonded silica using a Prospekt. Although the analytes display a "mixed" hydrophobic/hydrophilic behaviour, both breakthrough on the precolumn and adsorption to inner walls and surfaces can be prevented by adding Brij-35, a neutral surfactant, to the aqueous sample. The procedure has been tested for the analysis of surface water; detection limits typically are at the sub-μg/l level and repeatability is excellent. The automated system is robust and there are no maintenance problems. © 1994 Springer-Verlag.
Brouwer, E. R., Struys, E. A., Vreuls, J. J., & Brinkman, U. A. T. (1994). Automated determination of pyrethroid insecticides in surface water by column liquid chromatography with diode array UV detection, using on-line micelle-mediated sample preparation. Fresenius' Journal of Analytical Chemistry, 350, 487. https://doi.org/10.1007/BF00321794