Development and performance evaluation of portable 405 nm laser-induced fluorescence detector

A portable laser-induced fluorescence detector based on module design, which includes an excitation source of 405nm fibre-coupled stable spectra diode laser,a fluorescence collection module based on a fibre fluorescence optical fibre probe with an improved confocal optical arrangement,a fluorescence analysis module of Mini Fiber Grating Spectrometer. The advantages of the detector is compact, small size, low cost, high sensitivity, easy to operate.The performance of the detector is evaluated by fluorescein sodium. Water Raman peak S / N is 935.67. LOD of fluorescein sodium was 1.9×10-11g/L.Correlation of the fluorescence intensity was 0.9998 with the concentration from 10^-10 to 10^-12 g/L, the linear dynamic range was over 3 order. RSD of the fluorescence wavelength and intensity repeatability was 0.14% and 3.36% respectively. It is concluded that the 405nm LIFD has highly sensitivity,good repeatability,a wide linear range.