250 nm激光诱导土壤中多环芳烃的荧光检测系统

Detection System of 250 nm Laser Induce Fluorescence of Polycyclic Aromatic Hydrocarbons in Soil

为了提高激光诱导荧光(Laser-Induced Fluorescence,LIF)方法对土壤中多环芳烃(Polycyclic Aromatic Hydrocarbons,PAHs)检测的精度,以蒽、芘、菲三种多环芳烃的标准土壤混合物作为样本,通过紫外吸收光谱研究了这三种物质的最佳激发波长为250 nm,主要采用ND6000可调谐染料激光器、500is-sm型三光栅光谱仪和DK734-18F型ICCD构建了LIF方法测量土壤中多环芳烃的检测系统。在250 nm激光激发下,这三种PAHs的土壤混合样本的荧光发射光谱满足各自特征发射光谱,不同质量分数和其荧光强度线性相关系数达到0.97以上。实验结果表明该检测系统提高了对土壤中PAHs的检出限和线性相关性。

Laser-Induced Fluorescence is a safe and highly sensitive optical inspection method for detecting Polycyclic Aromatic Hydrocarbons （PAHs） in the environment. To improve the precision of the detection, we use as samples the anthracene-soil, pyrene-soil, and phenanthrene-soil mixtures, respectively. Through the measurements of ultraviolet absorption spectrum, we determine the optimal excitation wavelength of the three PAHs to be 250 nm. The detection system is constructed mainly by ND6000 tunable dye laser, 500is-sm spectrograph, and ICCD （DK734-18F）. With 250 nm laser, the fluorescence emission spectra of the three mixture samples are consistent with their characteristic emissions, respectively, and different mass fractions exhibit good linearity to the fluorescence intensities with the correlation coefficients up to above 0.97. It is demonstrated by experiment that the detection system improves the limit of detection and the linear correlation.