On-line phase-transfer catalysed dansylation of phenolic compounds followed by normal-phase liquid chromatography...

A study of the on-line phase-transfer catalysed dansylation of phenolic compounds is presented. The extraction-dansylation is performed in the extraction coil of a home-made flow-injection extraction unit. After phase separation, the organic phase is fed to a normal-phase liquid chromatographic system with fluorescence detection. Ethynyloestradiol, oestradiol and paracetamol are used as test compounds. The influence of temperature on the reaction is examined. Calibration graphs showed good linearity (r greater than 0.996) and limits of detection are satisfactory (8 x 10(-7) M for ethynyloestradiol, 2 x 10(-6) M for oestradiol and 5 x 10(-7) M for paracetamol). The method is not applicable for the assay of oxychinoline, phenylephrine and morphine.