Measuring of naphthalene fluorescence emission in the water with nanosecond time delay laser induced fluorescence spectroscopy method

In this paper, the time resolved laser induced fluorescence emission of naphthalene (C10H8) has been measured by both a time delay method and a high pass method. The sample was excited by laser pulse at 266 nm wavelength and Fluorescence emission was detected by an ICCD. In the high pass method, a high pass filter is placed in front of a spectrometer to eliminate the laser pulse scatter. On the other hand, in the time delay method, instead of a high pass filter, a nanosecond time delay is used between the incident laser light and the detection of fluorescence emission. An enhancement was observed in the S/N ratio in time delay method compared to the high pass method. The fluorescence lifetime and the limit of detection (LOD) quantities of naphthalene in water were determined in the time delay method. Linear calibration plot has provided detection limits in the ppb range.