Abstract
A combined GC–LOAS system (a gas chromatograph and a laser optoacoustic spectrometer) has been devised and comprehensively studied, and a number of typical chromatographic tasks solved with this system is given. The sensitivity of the OA detector used in the system with respect to the detectable absorption factor is 2 · 10−7 cm−1 which corresponds to a concentration sensitivity for methanol (λ = 9.695 μm) of about 10−10 g/cm3. It is shown that the chromatographic resolution almost does not become worse if the OA detector with a 2.7 cm3 chamber volume is used with a packed column. The experimental results are presented which show the identifying potentialities of the laser OA method in chromatographic analysis of a mixture of butanol isomers and the increased resolution of a chromatographic analysis of isopropyl alcohol admixture in ethyl alcohol. Also, it is shown how to solve the task of analyzing the xylene isomers which cannot be separated in the column. The laser OA method has been qualitatively compared with other selective methods in gas chromatography. Recommendations have been proposed for improving the characteristics of the combined GC–LOAS system.