Modulated anisotropy fluorescence for quantitative determination of carbaryl and benomyl

Two individual components in mixtures have been resolved by frequency domain fluorescence technique by measuring the observable quantities which characterize the anisotropy decay; differential anisotropy phase and modulated anisotropy ratio (MAR), which in turn are related to the rotational correlation time. The method presented here is capable of directly resolving binaries mixtures of fluorophores on the basis of differences in their rotational diffusion rates. Our results demonstrate that modulation anisotropy ratio measurements can be used for quantitative determination of small analytes, carbaryl and benomyl, having identical or nearly identical fluorescence spectra. This methodology can be applied with good results when the fluorophores have a suitable MAR difference.