A Rapid Method for Benzo[a]Pyrene Detection Using Synchronous Fluorescence Spectrometry

Abstract

The presence of Benzo[a]pyrene (BaP) in polycyclic aromatic hydrocarbons (PAHs) causes them to be extremely harmful and carcinogenic. Therefore, it is essential to develop a convenient and rapid method for BaP detection. Detection of BaP using conventional fluorescence spectrometry suffers from interference from the homologues of BaP. Synchronous fluorescence spectrometry can simplify spectra, promote selectivity and reduce light scattering interference, making it particularly suitable for analysis of trace PAHs in the environment. In this study, a quick method is proposed for BaP detection using constant-wavelength synchronous fluorescence spectrometry. The fluorescence spectra of 16 PAHs, provided by the Environmental Protection Agency (EPA), and their mutual interference was investigated. It was observed that only Benzo[k]fluoranthene (BKF) interfered with the BaP spectrum with Δλ =137 nm and that the other 14 PAHS had almost no fluorescence. Based on the overlap of the fluorescence spectra of BaP and BKF, a relative formula based on the Beer-Lambert Law was established relating the fluorescence intensity and concentration. The formula allows for the concentration of BaP or BKF to be determined when both fluorescence intensities are detected. In this method the linear concentration ranges for BaP and BKF were 40 to 360 ng mL-1 and 4 to 54 ng mL-1, respectively, with a RSD of 3.42% and 3.48% and a LOD of 0.8206 ng mL-1 and 0.1256 ng mL-1, respectively. In order to verify the feasibility of this method, we compared it with HPLC. A t-test showed that there was no significant difference between the average value and precision of the two methods.