LASER-INDUCED FLUORESCENCE DETECTION OF NATIVE-FLUORESCENT ANALYTES IN COLUMN LIQUID-CHROMATOGRAPHY, A CRITICAL-EVALUATION

This paper critically evaluates aspects that need to be considered when applying lasers instead of conventional lamps in fluorescence detection combined with column liquid chromatography (LC). To exclude the often underestimated role of chemical derivatization reactions as far as detection limits are concerned, emphasis is on analytes showing native fluorescence. First of all basic features of both continuous wave and pulsed lasers are considered, including a quantitative treatment of saturation and photodecomposition effects. Subsequently a detailed treatment on signal-to-noise in laser induced fluorescence (LIF) is presented, the various definitions of detection limits operative in the literature are compared and flow cell constructions are considered. The paper ends with a comparison between conventional fluorescence and LIF detection in LC, an overview of published data on detection limits and a discussion on future trends.