Some applications of near-ultraviolet laser-induced fluorescence detectionin nanomolar- and subnanomolar-range high-performance liquid chromatography or micro-high-performance liquid chromatography

In this work we present some applications of near-UV laser-induced fluoresc ence (LIF) with micro-HPLC (mu HPLC) and HPLC. To test the sensitivity of t he detection, we used pyrene and aflatoxins, because both of these molecule s exhibit native fluorescence. Then we studied catecholamines derivatized w ith I,2-diphenylethylenediamine. The results show that we were able to reac h better sensitivity levels than previously described in LIF studies. For c atecholamines, a 50-fold increase in sensitivity compared to conventional f luorescence was obtained. These results indicate that LIF detection associa ted with HPLC or mu HPLC can be used to detect very low concentrations of s ubstances that can be excited in the near-UV range after labeling at nanomo lar concentrations. (C) 2001 Elsevier Science B.V. All lights reserved.