2-(4-Carboxyphenyl)-6-N,N-diethylaminobenzofuran: a useful reagent for the sensitive determination of alcohols by high-performance liquid chromatography with fluorimetric detection

A simple and highly sensitive method for the determination of short, medium and long-chain alcohols using high-performance liquid chromatography with fluorimetric detection is described. The alcohols were derivatized to their corresponding esters with (4-carboxyphenyl)-6-N,N-diethylaminobenzofuran. The esterification reaction proceeded rapidly and smoothly in acetonitrile at 60 degrees C with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (a coupling agent) in the presence of 4-dimethylaminopyridine (a base catalyst). The resulting esters of alcohols from methanol to eicosanol (C1-C20-ol) were separated on a reversed-phase column (Ultrasphere C8) with gradient elution (acetonitrile-water) and detected fluorometrically (excitation 387, emission 537 nm). The lower limits of detection (signal-to-noise ratio of 3) for the derivatized alcohols were in the range of 0.2-0.5 pg.