利用二维相关红外光谱方法确定气体最优定量波数区间

Ascertaining the Optimal Quantitative Wavenumber Range of Gas with Two-Dimensional Correlation Infrared Spectroscopy

气体检测中需选用最优波数范围来进行气体光谱的定量分析。传统波数范围的选取主要根据标准光谱的特征吸收,存在抗干扰性较差、在实际情况中容易出现较大偏差的问题。文章将二维相关红外光谱方法用于气体检测,对SO2,NO及NO2进行光谱结构分析和光谱信息发掘,以确定最优定量波数区间。以浓度值为微扰量,用含不同浓度某气体成分的一组红外吸收光谱,做二维相关得到SO2,NO及NO2的动态光谱,利用同步相关光谱和异步相关光谱来分析对气体浓度变化最敏感的波数区间,确定了被测气体定量分析的优选波数范围,包括一系列独立的波数点和连续的波数区间。作为一种新颖的最优定量波数区间选取方法,其得到的结论与理想的分析谱带选取的结果相吻合,证明了此方法的有效性。

It is important to determine the optimal wavenumber ranges of spectra for quantitative analysis in gas detection. In traditional way, selection of optimal wavenumber ranges is based on the absorption characteristics of standard spectra, while this may introduce some deviation to the result due to its low capability of anti-interference. Two-dimensional correlation infrared spectroscopy technology was applied in gas detection in the present paper. The spectral structure and spectral information of SO2, NO and NO2 were analyzed in order to determine the optimal wavenumber range. The dynamic spectra of the detected gas were gained by the two-dimensional correlation analysis of a series of infrared absorption spectra according to changing concentrations. The most sensitive wavenumber ranges to gas concentration were determined by combining synchronous correlation spectra and asynchronous correlation spectra. These were taken as the optimal wavenumber ranges for quantitative gas analysis, which included a series of unattached wavenumber points and continous wavenumber ranges. Results showed that the selected wavenumber ranges were consistent with theoretic analyzed results. Two-dimensional correlation infrared spectroscopy can be a novel way to determine the optimal spectral range for gas analysis.