Identification of polycyclic aromatic hydrocarbons (PAHs) in soil by constant energy synchronous fluorescence detection

In this paper, a novel method of constant energy synchronous fluorescence (CESF) was proposed to the simultaneous determination of different polycyclic aromatic hydrocarbons (PAHs) in a mixture of 16 components. When different appropriate intervals of the constant energy (Δν = 1400 or 4800 cm−1) were chosen during constant energy synchronous scanning, 13 PAHs could be identified and quantified by the corresponding synchronous spectra. Results show that their linear relations are fine and the limits of detection (LODs) were between 0.2 and 7.6 ng ml−1. Then the application of CESF method proposed in the analysis of the real soil samples under the optimum conditions indicated that 11 PAHs could be identified and the total concentration of PAHs in a real soil sample is 5.1 μg g−1, most of PAHs in the soil samples had three or four rings. Recoveries of these PAHs were from 70.9 to 121.4% in most cases. This CESF method is a simple, rapid, sensitive method with high resolution and also suitable to analyze the complex mixtures of PAHs in other environmental samples.