Determination of three polycyclic aromatic hydrocarbons in tea using four-way fluorescence data coupled with third-order calibration method

Abstract

The content of polycyclic aromatic hydrocarbons (PAHs) in tea has attracted widespread attention. In this study, the strategy of four-way fluorescence data coupled with third-order calibration method based on four way parallel factor analysis (four-way PARAFAC) was used to determine phenanthrene, naphthalene and acenaphthene in tea. A new method, introducing an additional temperature mode into the three-way fluorescence data set, was proposed to acquire a four-way data array. The feasibility of the method was validated by experiments. The four-way PARAFAC could give satisfactory analytical results for the determination of three PAHs in tea. The average spiked recoveries were (100.9 ± 7.8)% for phenanthrene, (94.6 ± 8.6)% for naphthalene, (96.0 ± 9.8)% for acenaphthene. The root-mean-square error of prediction (RMSEP) values were 0.495 μg L−1 for phenanthrene, 0.841 μg L−1 for naphthalene, 0.577 μg L−1 for acenaphthene. The average relative predictive errors (ARPE) values for three PAHs were <2.35%. The limits of detection (LOD) of three PAHs were between 0.026 and 0.14 μg L−1. Generally, these results obtained by four-way PARAFAC were better than that of three-way PARAFAC. In addition, analytical figures of merit, such as Sensitivity, Selectivity and Analytical sensitivity, were calculated for three PAHs to evaluate the methods. The results demonstrated that the four-way PARAFAC was more suitable for the determination for three target analytes in this study.