Abstract: ：Polycyclic aromatic hydrocarbons（PAHs）, which have low residual amounts and various types, are important environmental pollutants. It is difficult to analyze the overlapping fluorescent peaks of PAHs in complex systems by conventional fluorescence spectroscopy. Two-dimensional（2D）fluorescence correlation spectroscopy was used to analyze the fluorescence peaks of a mixture of three PAHs, benzo[a]pyrene, benzo[ghi]pyrene and benzo[k]fluoranthene. A total of 30 mixed solution samples were prepared, and the one-dimensional（1D）fluorescence spectra were collected. On this basis, synchronous and asynchronous 2D correlation spectra were calculated for the 1D dynamic fluorescence spectra under the external disturbance of PAHs concentration. Based on the uncovered fluorescence peak of benzo[ghi]perylene at 500 nm in 1D fluorescence spectra, the sources of overlapping peaks were confirmed in mixed solutions in terms of the positive and negative cross peaks in synchronous spectra and the presence or absence of cross peaks in asynchronous spectra. The fluorescence peaks at 405, 425, 459 and 491 nm were assigned to benzo[a]pyrene; the fluorescent peaks at 471, 480 and 500 nm were assigned to benzo[ghi]perylene; the fluorescent peaks at 417, 433 and 443 nm were assigned to benzo[k]fluoranthene. The results showed that 2D fluorescence correlation spectroscopy can effectively resolve the overlapping fluorescent peaks of PAHs in complex systems and provide more spectral characteristics information.

Key words: two-dimensional fluorescence correlation spectroscopy, benzo[a]pyrene, benzo[ghi]perylene, benzo[k]fluorene, overlapping peak, resolution