光化学荧光法测定蔬菜中残留的氯菊酯

Determination of permethrin in vegetable by photochemical-fluorimetry

目的建立蔬菜中氯菊酯残留量的光化学-荧光分析方法。方法在pH 9.29的B-R缓冲溶液中,氯菊酯在紫外光照射下发生光化学反应,其荧光强度明显增强,激发波长为281 nm,发射波长为330 nm,用荧光分光光度计测定。结果氯菊酯在0.004～0.036μg/mL浓度范围内与荧光强度呈良好的线性关系,检出限为0.14ng/mL,相对标准偏差为1.0%。结论该方法灵敏度高,选择性好,适合蔬菜中氯菊酯残留量的测定。

Objectives To establish a method for the determination of permethrin residues in vegetables by photochemical-fluorimetry. Methods Permethrin is a lower fluorescent substance, and its fluorescence in-tensity can be enhanced under the irradiation of ultraviolet light in B-R buffer medium (pH=9.29). The analyte had maximum excitation and emission wavelengths at 281 nm and 330 nm. Quantification was achieved by fluorimetric method. Results The linearity between fluorescence intensity and concentration of permethrin were in the range of 0.004～0.036μg/mL. The detection limit was 0.14 ng/mL. The relative standard deviation (RSD) was 1.0%. Conclusion The method has good sensitive and selectivity , it is suitable for the determina-tion of permethrin residues in vegetables.