As one of the important branches of analytical chemistry,the spectral analysis method has an excellent performance in quantitative,qualitative and structural analysis.However,in the actual spectral analysis process,due to the influence of experimental equipment and the environment,the spectral characteristics of the sample to be measured may be weak.Besides,there are overlapped peaks in the spectrum when analyzing some complex sample systems,which makes it difficult for quantitative analysis.Two-dimensional correlation spectroscopy(2DCOS),which originated from the last century,is a new method of spectral measurement and spectral analysis.Using perturbation,2DCOS can effectively enhance the spectral resolution and signal-to-noise ratio.But at all times the 2DCOS has used temperature,pressure and other orderly external changes as the perturbation,which limits its actual application.This study is based on the theory of 2DCOS and attempts to add new perturbations to the analysis.Based on the method research,the 2DCOS software is developed by using Python language,and the performance of the software is verified in typical molecular and atomic spectroscopy.The main research contents of this paper are as follows:1.In this paper,the theory of 2DCOS is studied deeply,and the 2DCOS software is written by using Python language with the new variables as the perturbations.2.The 2DCOS software developed is applied in Open-path Fourier Transform Infrared Spectroscopy(OP-FTIR)analysis.In the OP-FTIR,the energy of the light source and the response of the detector is fixed,but the detected airflow is constantly changing.Therefore,the flow of the gas is used as a perturbation of the 2DCOS.When the ethanol gas is detected by the OP-FTIR method directly,the obtained spectral characteristics are relatively weak.After analyzing with the 2DCOS,the spectral characteristics of the ethanol gas have been significantly enhanced.This proves that 2DCOS can enhance the gas detection sensitivity of OP-FTIR.When use the OP-FTIR method to directly detect the volatiles of two kinds of liquor(Fenjiu,Luzhouteniang),the original spectrum of the two obtained are very similar,and the two cannot be distinguished.After analyzing the two-dimensional correlation asynchronous spectroscopy,two kinds of liquor volatiles can be distinguished,which proves that 2DCOS can improve the gas recognition ability of the OP-FTIR.3.The 2DCOS software developed is applied in Laser-induced Breakdown Spectroscopy(LIBS)analysis.Since the laser energy is easy to be adjusted in the LIBS system,the laser energy is used as a perturbation of the 2DCOS.Taking elements such as Cu,Cr,and Ni in standard steel blocks as examples,the effect of the 2DCOS on the SNR of LIBS is studied.The results show that the SNR of the LIBS detection method is increased by 2 to 6 times,and the detection limit is reduced by about 2 times.Taking soil as an example,the separation effect of the 2DCOS on overlapped peaks in LIBS is studied.The result shows that the spectral peaks of different elements could be separated by the 2DCOS,which improve the spectral resolution.In summary,this study expands the form of perturbation in 2DCOS,develops the2 DCOS software,verifies the performance of the software in molecular and atomic spectroscopy,and improves detection capabilities for OP-FTIR and LIBS.It provides a reference for the application of 2DCOS in other molecular and atomic spectroscopy. |