Characteristics Extraction And Detection Of Polycyclic Aromatic Hydrocarbons In Soil Using 2D Correlation Fluorescence Spectroscopy

In recent years,soil pollution has become increasingly serious.It is urgent to develop a real-time online,rapid and accurate detection method for polycyclic aromatic hydrocarbons(PAHs)in soil.Fluorescence spectroscopic method has been used to detect PAHs in soil due to its speed,simplicity and real-time online detection.However,the conventional fluorescence spectra can not effectively extract characteristic fluorescence information of PAHs in complex soil systems because of diversity and trace of PAHs,and the effects of soil physical and chemical parameters on fluorescence.In this paper,the technology of two-dimensional(2D)correlation fluorescence spectroscopy was used to extract characteristic fluorescence information of PAHs,and used to construct a quantitative analysis model for PAHs pollutions.The main research contents are the following three aspects:(1)The method for extracting the characteristic fluorescence information of PAHs was proposed using 2D correlation fluorescence spectroscop.The typical PAHs of anthracene and pyrene were used as the research object.With excitation wavelength as external disturbance,2D correlation fluorescence spectra were calculated,and the overlapping characteristic fluorescence information of anthracene and pyrene was extracted.According to the existence or inexistence,positive and negative values of cross peak in the synchronous and asynchronous 2D correlation fluorescence spectra,the characteristic peaks anthracene and pyrene were confirmed.The validity of the proposed method was verified.(2)The effects of soil physical and chemical parameters on the fluorescence of PAHs were investigated.The typical PAHs anthracene was used as the research object.Firstly,the conventional fluorescence characteristics of anthracene in different soil particle size and humidity were studied.2D correlation fluorescence spectra were calculated respectively under the external disturbance of anthracene concentration,the soil particle size and the soil moisture,for studying the effects of soil particle size and humidity on the fluorescence characteristics of anthracene.Finally,the statistical analysis of ANOVA method was used to study the effects of anthracene concentration,soil particle size and soil moisture on the fluorescence intensity.The results showed that the concentration had the most significant effect on the fluorescence intensity,and the particle size had relatively little effect.(3)A quantitative analysis method of PAHs in soils was developed based on 2D correlation fluorescence spectroscopy.2D correlation fluorescence spectra of anthracene and phenanthrene in soil were calculated under the external disturbance of excitation wavelength.On this basis,the N-way partial least squares(N-PLS)models for quantitative analysis of anthracene and phenanthrene in soil were established.Compared with 3D fluorescence spectra,the proposed method can effectively improve the prediction accuracy of PAHs in soil.In this paper,2D correlation fluorescence spectroscopy was used to extract and detect the characteristic information of PAHs in the environment.The results obtained in this paper provide a theoretical and experimental basis for the application of 2D correlation fluorescence spectroscopy in the detection of PAHs in the environment.