Abstract
In this study the potential of using visible semiconductor lasers as the excitation source for laser-induced fluorescence spectroscopy (LIF) of nano-liter to pico-liter samples has been evaluated. The incentive to work with LIF in the upper visible and near infrared wavelength region is the possibility to design a system that is not limited by any background fluorescence, e.g. from a capillary flow-cell or the liquid eluent [1]. The system described here was mainly designed for applications to chemical ultra-trace analysis when combined with miniaturized separation techniques such as capillary liquid chromatography and capillary electrophoresis. A concentration limit of detection in the lower pico-molar range (6.3 - 58 · 10-12 mol/L) was obtained for a model fluorescent compound, HITCI (1,1’,3,3,3',3'-hexamethyl-indotricarbocyanine iodide). The smallest illuminated volume was 0.7·10-12 L using an 11 μm inner diameter fused silica capillary flow-cell. These figures compares well with the best obtained using conventional gas-lasers for LIF [2,3]. An important advantage with the semiconductor LIF system, except from that it is inexpensive, is that the compactness and the high performance of the components makes it highly suitable for portability.
© 1992 Optical Society of America
PDF ArticleMore Like This
Kevin J. Jordan, Robert H. Lipson, and Hafed A. Bascal
MK6 OSA Annual Meeting (FIO) 1992
Stephen L. Pentoney and Kenneth D. Konrad
CWP1 Conference on Lasers and Electro-Optics (CLEO:S&I) 1992
Richard N. Zare
MA1 Laser Applications to Chemical Analysis (LACSEA) 1987