HIGH-SENSITIVITY FLUORESCENCE DERIVATIZATION FOR THE DETERMINATION OFHYDROXY COMPOUNDS IN AQUEOUS-SOLUTION BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

The utility of the fluorescent labelling reagent 6-aminoquinolyl-N-hyd roxysuccinimidyl carbamate (AQC) for the determination of alcohols in aqueous media was evaluated. The labelling conditions were optimized f or C-1-C-8 alcohols. Under the very mild reaction conditions of 25 deg rees C for 1 min in a basic buffer, all the alcohols tested were deriv atized with the reagent to yield highly stable fluorescent carbamate d erivatives. The maximum excitation (290 nm) and emission (365 nm) wave lengths were the same for all the alcohols tested. The stability of th e derivatives and their yield were affected by the chosen pH in the ra nge 6-9.5 and by the steric hindrance of the alcohol function. All the derivatives obtained with AQC were completely separated by reversed-p hase high-performance liquid chromatography on a 20-cm C-18 column wit h a gradient of aqueous sodium acetate buffer (pH 6) and acetonitrile. The detection limit (S/N = 3) with fluorescence detection is at the p icomole level. Some preliminary applications in the fields of foods an d beverages are described.