A laser diode double-pumped solid-state laser-induced fluorescence detector for capillary electrophoresis and liquid chromatography

A laser-induced fluorescence detector for both capillary electrophoresis (CE) and high performance liquid chromatography (HPLC) based upon a confocal scheme using a laser diode double-pumped solid-state (LD-DPSS) laser emitting at 473 nm, is described and evaluated. To carry out HPLC measurements, a novel postcolumn flow cell with a 7-mu L cell volume was designed. The excitation axis and two fluid channels of the flow cell are on the same plane and form a 120 degrees angle. The detector response was linear over approximately 0.5-50 nM with a concentration detection limit of 5 pM for fluorescein isothiocyanate (FITC) by CE. The analysis of FITC-labeled amino acids and riboflavin in soft drinks by CE-LIF and the analysis of FITC-labeled phenylalanine and riboflavin in real samples by HPLC-LIF were also demonstrated