Monitoring PAH-contaminated soil using laser-induced fluorescence (LIF)

The heterogeneity and opacity of soil matrices pose considerable challenges for the quantification of soil contaminants. In order to investigate the feasibility of applying the Laser-Induced Fluorescence technique to measure contamination levels of soils, statistical analyses of contaminant levels and intensity of fluorescence were investigated in relation to soil properties. A significant correlation (R2 > 0.97) between contaminant levels and intensity of fluorescence was shown under different matrix conditions, such as moisture content and particle size distribution. Higher fluorescence intensities were obtained from soils with higher sand and moisture content. The statistical results in relation to the interaction between fluorescence intensity and matrix properties rejected the hypothesis that all properties of the matrices and contaminants had an equal influence on fluorescence. This implied that the concentrations of contaminants had the greatest contribution to the fluorescence intensity, but other variables also showed a considerable influence.