Development of a HeCd Laser-Based Fluorescence Detector for Analysis of Derivatized Biogenic Amines

Abstract

The development of a highly sensitive laser-induced fluorescence (LIF) detector for HPLC is described. It was specifically designed to monitor the fluorescence emitted from biogenic amines which were derivatized by naphthalenedicarboxaldehyde (NDA) in the presence of cyanide ion. The product of the amine derivatization, cyanobenz[f]isoindole (CBI), absorbs radiation at the output wavelength of the HeCd laser (441.6 nm). Optimization of detector sensitivity included evaluation of both optical components and cell configurations. A laser dye, coumarin 7, served as the test analyte because its native spectral properties coincided with those of the CBI-amine adducts and because no derivatization step was required for each injection. A limit of detection (LOD) on the order of 2 × 10−12 M was reproducibly observed.