A novel detecting system with full fluorescent spectra for pesticides

摘要

A detecting system is developed applying the technologies of fiber-optic sensing, grating dispersion and multi-channel image sensing (Charge Coupled Device) based on the fluorescence mechanism of carbaryl. In this system, a pulsed xenon lamp is used as an excitation light source, optical fibers are selected to transmit and detect fluorescence, fluorescence dispersion is implemented with a small-sized flat field grating spectrometer and data gathering and A/D conversion are conducted with a high speed signal processing module. Moreover, the system is used to measure the fluorescence characteristics of carbaryl. The results show that a full fluorescence spectrum of carbaryl can be obtained in a single exposure under a UV excitation wavelength of 319nm, has a good linear relationship in the range of 4.0～100.0 ng/mL of carbaryl liquor and the minimum detecting limit is 4.0ng/mL with the linear correlation coefficient r being 0.9986. When this instrument is likewise applied for measuring carbaryl in river and ground water, the recovery may approach 100%.