Selective determination of carbaryl and benomyl by fluorescence polarization

The potential of fluorescence polarization for fluorescence mixture resolution was assessed and compared with liquid chromatography (LC). Careful selection of excitation wavelengths and the use of an appropriate viscous medium (glycerine) allows significant differences in polarization to be obtained. For two component mixtures, information about fluorescence polarization and the total intensity of the samples is sufficient to calculate the relative contributions when the polarization of the two pure components are known. The results obtained for benomyl and carbaryl show detection limits (K S-B/m) of 11.4 ng ml(-1) and 1.2 ng ml(-1), mid-range relative standard deviations of 0.8% and 0.9% n=3 and recoveries between 104 and 113% and 91 and 107%, respectively. (C) 2000 Elsevier Science B.V. All rights reserved.