Determination Of Carbamate Pesticide And Diethylstilbestrol By Fluorescence Spectroscopy

The using of Carbamate pesticide and diethylstilbestrol can bring great benefits to mankind, but on the other hand, overusing of them can cause great harm to human healthy and ecological environment. Therefore, the establishments of sensitive, efficient and simple determination methods of carbamate pesticides and diethylstilbestrol have great significance. Synchronous fluorescence spectroscopy is more advantageous than conventional fluorescence, such as simple spectra, high selectivity and low interference, especially for multi-component mixtures. Some organic compound itself can not emit fluorescence, thus the structure must be altered by photochemical reaction to produce a new product which can be detected by fluorescence. The indirect determination method is simple, fast and specified, extends research field of fluorescence analysis.First, a P-cyclodextrin enhanced synchronous fluorescence spectroscopic method for the simultaneous determination of propoxur and carbaryl was established. When△λ=30nm, some important experimental parameters effecting the fluorescence intensity, i.e., pH, the type and dosage of ordered medium and reaction time were investigated and the optimum condition:pH8.0, the concentration of β-cyclodextrin of2.5×10-3mol/L. At266nm, a good linearity relation between the derivative synchronous fluorometry of system and propoxur concentration in the range of30.0～600ng/mL was obtained with a correlation coefficient of0.9978. A detection limit of10.0ng/mL was obtained. At290nm, a good linearity between the synchronous fluorometry of system and the concentration of carbaryl in the range of3.00～130ng/mL was obtained with a correlation coefficient of0.9990, and a detection limit was0.8ng/mL. The method has been applied to the determination of propoxur and carbaryl in cucumber with recoveries of propoxur in the range of90～94%and carbaryl in the range of83～96%. The experimental result showed that the method was accurate and reliable. The mechanism of the fluorescence enhancement of β-cyclodextrin was also discussed.Second, the determination method of diethylstilbestrol was developed. At the optimum condition, the irradiation time of2.5h, pH of6.0and λem=398nm, a good linearity between the fluorescence intensity and the concentration of diethylstilbestrol in the range of2.00～136ng/mL was obtained with a correlation coefficient of0.9978and a detection limit was0.6ng/mL. The method had been applied to the determination of diethylstilbestrol in milk with recoveries in the range of98～101%. The experimental result showed that the method was simple, fast and sensitive.