Forward Degenerate Four-Wave Mixing as a Detection Method in Liquid Separation Systems: Improving Detection Limits by Means of a Fabry—Perot Interferometer

Autor: Hoornweg, Gerard Ph., De Beer, Tjipke, Velthorst, Nel H., Gooijer, Cees
Zdroj: Applied Spectroscopy; July 1997, Vol. 51 Issue: 7 p1008-1011, 4p
Abstrakt: A simple, small, and low-resolution confocal Fabry–Perot interferometer (CFP) has been developed to improve the signal-to-noise ratio (S/N) in forward degenerate four-wave mixing (F-D4WM) detection, coupled to high-performance liquid chromatography (HPLC). Its appropriateness is based on the difference in coherence between the F-D4WM signal and the background stray light. A detailed description of the specially designed CFP and its performance is presented. The improvement in S/N was calculated from the chromatographic peaks recorded after an HPLC separation of 1- and 2-aminoanthraquinone. The concentration limit of detection (LOD) was improved by a factor of 30; for 1-aminoanthraquinone it was 2 × 10−8M injected (corresponding to about 3 × 10−9M in the detector cell), which is quite favorable in view of its low molar extinction coefficient being 2000 M−1cm−1at the utilized laser wavelength (514.5 nm).
Databáze: Supplemental Index