基于同步-导数荧光光谱法的多组分农药残留测定的研究

多组分农药残留物的荧光检测中，由于组分间结构与化学性质相似，导致荧光光谱相互重叠，常规荧光光谱法难以同时进行测量。利用同步-导数荧光光谱法对西维因与克百威这2种常用农药的荧光光谱进行了研究，并试验了pH值对两者荧光特性的影响。在pH为7.8的条件下，选择Δλ=60 nm，在250～450 nm的波长范围内对两者混合溶液进行了同步荧光光谱扫描，并做一阶导数处理。实验结果表明，两者的同步导数荧光光谱完全得到了分离，消除了彼此间的干扰，能够对两者的混合溶液进行同时测定。西维因与克百威的线性范围分别为0.013～1.156 μg·mL-1与0.025～1.042 μg·mL-1,检出限分别为0.013 μg·mL-1与0.025 μg·mL-1,回收率分别为98%～104%与96%～103%;相对标准偏差均低于2.25%。

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 Δλ=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 μg·mL-1 and 0.025-1.042 μg·mL-1, the detection limit is 0.013 μg·mL-1 and 0.025 μg·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%.