红外激光光声光谱检测范围扩展的研究

本文对红外激光光声光谱检测范围扩展进行了研究。测试系统采用了 DNP 色谱柱,设计了可通过试样气流的可加热亥姆霍兹共振光声池,采用了两只光声池串联差分与锁相放大的办法以减小本底噪声。实验对含有乙酸乙酯和乙酸丁酯有机化合物的试样进行了分析,获得了光声色谱图。实验结果表明,当光声池前连色谱柱,即可检测含重分子量有机化合物的混合物,扩大了激光光声光谱的检测范围。

RESEARCH OF DETECTIVE RANGE EXTENSION OF INFRARED LASER PHOTOACOUSTIC SPECTROSCOPY

In this paper the detective range extension of Infrared Laser Photoacoustic Spectroscopy(ILPS)is studied.In the measurment system a chromatography column is used.A Helmholtz resonance pho-toacoustic cell is designed whic hcan be warmed and allowed a continu-ous flow gas of sample to pass through.Two similar photoacoustic cells are used in series.Their photoacoustic are differenced and lock-in ampli-fied.Then the background noise of detective photoacoustic cell is reduced.The mixture sample of the organic compound of ethyl acetate and butyl acetate is analyzed.The photoacoustic chromatograpy diag-rams are achived.The test results have proved that the mixture containing the heavy molecular weight organic compound may be detected if a hromatograpy column is placed before the photoacoustic cell and therefore the detective range of ILPS is extended.