[Study on the determination of multicomponent pesticide residual based on synchronous-derivative fluorimetry]

In the multicomponent fluorescence measurement of pesticide residual, the comparability of construction and chemical property among the components leads to the overlap of the fluorescence spectra, so it's very difficult to do simultaneous measurment with conventional fluorescent spectroscopy. Using synchronous-derivative fluorimetry, the fluorescence spectra of carbaryl and carbofuran and the effect of different pH on the pesticides were studied, with pH 7.8, and delta lamda=60 nm, synchronous fluorescence scan of the mixed solution in the wavelength range of 250-450 nm, was carried out, and transformed to first order derivative fluorescence spectrum. The experiment results indicate that their synchronous-derivative fluorescence spectra were separated absolutely, eliminating the disturbance between them; the fixed solution can be measured simultaneity. For carbaryl and carbofuran, the linear range is 0. 013-1.156 microg x mL(-1) and 0.025-1.042 microg x mL(-1), the detection limit is 0.013 micorg x mL(-1) and 0.025 microg x mL(-1), and the average recovery is 98%-104% and 96%-103%, respectively. The relative standard deviations (RSDs) of them are all under 2.25%.