为了对复杂体系的多环芳烃进行定性识别和定量分析, 构建了基于二阶校正法的荧光检测系统。利用二阶校正法在三维荧光数据处理中的优势, 达到多种混合多环芳烃分离和鉴别的目的。采用FS920荧光光谱仪测量并分析了萘(NAP)、苊(ANA)及两者混合物的荧光光谱特性, 发现NAP溶液有一个荧光峰λex/λem=290/322 nm, ANA溶液存在两个荧光峰分别为λex/λem=290/322 nm和λex/λem=290/336 nm, NAP和ANA荧光光谱重叠严重, 并且不同浓度配比混合物的荧光光谱具有差异性。通过将二阶校正法与三维荧光光谱法相结合, 实现对多环芳烃混合物的浓度检测。分别采用平行因子(PARAFAC)算法和自加权交替三线性分解(SWATLD)算法对光谱数据进行分解。结果表明: 两种算法对NAP和ANA混合物均有较高的分辨能力, 预测平均回收率均在95%~99%、均方根误差均小于0.2 μg/L。相比之下, SWATLD算法的检测效果更好。

In order to achieve qualitative identification and quantitative analysis of complex systems of Polycyclic Aromatic Hydrocarbons (PAHs), fluorescence detection based on second-order calibration methods was proposed. The spectral data of complex systems of PAHs were identified and decomposed by exploiting second-order calibration methods to analyze three-dimensional fluorescence data. The fluorescence spectra of acenaphthene (ANA), naphthalene (NAP), and their mixture were obtained using a FS920 steady-state fluorescence spectrometer. Analysis of their fluorescence spectra revealed a characteristic fluorescence peak of NAP at λex/λem=290/322 nm and the existence of two characteristic fluorescence peaks for ANA at λex/λem=290/322 nm and λex/λem=290/336 nm. The results indicate that the fluorescence spectra of ANA and NAP overlap significantly. Moreover, when the concentration ratios are different, the fluorescence characteristics of the mixture are different. Second-order calibration methods combined with three-dimensional fluorescence spectroscopy was applied to precisely detect the concentration of the solution. Parallel factor analysis (PARAFAC) and self-weighted alternating trilinear decomposition (SWATLD) were adopted to decompose the spectral data. The experimental results show that both algorithms exhibit a high resolution for the mixture of NAP and ANA, and the average recovery rate is between 95% and 99% with a root mean square error less than 0.2 μg/L. However, the SWATLD algorithm shows a better detection result.