On-Line Identification of Gas Chromatographic Fractions by a Raman Multichannel Spectrometer

Abstract

A Raman multichannel system is described which is feasible for the on-line identification of fractions separated by gas chromatographic columns. In Raman multichannel systems, the sensor, i.e., the laser focus, is small enough and the possible recording times are short enough to avoid any affliction of the separation process, even with capillary columns in use. At the measurements described, capillary columns with a length of 15 m and an inner diameter of 0.25 mm were employed. The detection limit was at about 1 to 10 nl of one fraction corresponding to about 1 to 10% of the total amount of sample suited for capillary columns.

On-line detection of mesogenic azoxybenzenes by combined liquid chromatography and Raman spectrometry

“…The chemically modified silica surface provides an effective stationary phase which is not only highly reproducible but has the advantages of greater capacity and a more controllable selectivity than the unmodified silica. The chromatographic properties of the effective stationary phase have been described recently as being determined by the combination of solvated bonded species and solvated substrate which is controlled by the mobile phase composition (3)(4)(5)(6)(7). Thus, the solvated bonded species contributes to, but does not comprise, the stationary phase, and the substrate must also be considered.…”

Raman spectrometry

“…Experiments which link GLC and Raman spectroscopy have demonstrated the analytical possibilities of such systems (25,26). Low sample concentrations frequently restrict the use of conventional Raman spectroscopy.…”