Study On Optical Fiber Fluorescence Measurement System For Concentration Of Pesticides Residua

According to incomplete statistic, species of pesticides in use is about 5,457 at present. With development of agriculture science and technology, organic pollutants which pesticides bring have existed in Agro-Animal manufacture of many countries and brought serious harm and pollution. Though pesticide residua is trace, they also can do harm to mankind's life and health. Presently, many diseases which are brought by pesticides have been discovered and potential harm to health of pesticide residua has catched international extensive. So it becomes exceptional important to detect pesticide residua and their metabolites.Fluorescence analysis method has an advantage of high sensitivity, strong selectivity and simpleness and is fit for online monitoring field. With the rapid development of electronics and optical-fiber technology, fluorescence analysis technology shows more and more superiority in industry, agriculture and medicine. Especially in pesticide residua detection, fluorescence spectrums of tens of dozens kind of pesticides have been detected and analysis instruments have been developed by means of combining optical-fiber sensor technology.Based on the theory analysis, we achieved several typical pesticides' fluorescence spectrums. Based on this, we develop a new optical-fiber fluorescence measurement system which is used in monitoring concentration of pesticide residua combined with optical-fiber sensor and weak signals measurement technology. The main research work includes:The best exciting wavelength and fluorescence spectrums of several typical species of pesticides (Carbamate, benzoylurea and imidacloprid) have been obtained by making use of existing experimental equipments. At the same time, we study influence of irradiation time, PH and fluorescence quencher on fluorescence intensity.Weak signals are measured by high-performance photodetectors (PMT and PIN) transiting optical signal into electrical signal. Noise can be reduced by amplifying and filter circuit. MCS-51 completes signals' sampling,memory and processing. Pesticides' work curve, recovery, veracity, precision and repeatability are determined. Measurement results are compared with other method in the same condition.