农药荧光全光谱检测与分析系统研究

A detecting system with full fluorescence spectrum for pesticides

基于有机物农药的荧光机理,利用光纤传感技术、光栅分光技术和多通道图像传感器（Multi-Channel Image Sensor）技术提出了一种用于有机农药的荧光全光谱检测与分析系统。系统以脉冲氙灯为激发光源,采用光纤进行传输和探测荧光,以自制的小型平场光谱仪对荧光进行色散分光,并设计了相应的高速数据采集电路,实验结果由微机进行分析。利用该系统实现了对西维因农药的荧光光谱的检测和荧光强度与农药浓度的分析。结果表明,以319nm波长紫外光为激发光,一次曝光可获得西维因农药的荧光光谱,光谱带宽为160nm;系统的最小检测浓度为4.0×10^-3mg/L,农药浓度在4.0×10^-3～100.0×10^-3mg/L之间时系统具有较好线性关系,线性相关系数r为0.9986。用该仪器对河水和地下水中痕量西维因进行了测量,回收率接近100%。

A measurement and analysis system is put forward by using the technologies of fiber-optic sensing,dispersion of grating and multichannel image sensing（CCD） based on fluorescence mechanism of the organic pesticide.A pulsed xenon lamp is chosen as an excitation light source.Optical fibers are used to transmit and detect fluorescence.A small-sized self-made flat field grating spectrometer is used to implement fluorescence dispersion and the high-speed data processing circuit is designed to collect signals.The experiment results are analyzed by a computer.It is used to measure the fluorescence of carbaryl.The results show that it can obtain a full fluorescence spectrum of carbaryl in a single exposure under the UV of 320nm.It has a good linear relationship in the range of 4.0×10^-3～100.0×10^-3 mg/L and a minimum detecting limit is 4.0×10^-3 mg/L and a linear correlation coefficient r is 0.9986.The instrument is applied to measure carbaryl in river water and ground water.The recovery approaches 100%.