Rapid and simple HPLC method for the simultaneous determination of urocanic acid isomers in human skin

Abstract

A high-performance liquid chromatography (HPLC) method for the determination of urocanic acid isomers extracted from human skin has been developed. Urocanic acid is a compound present in skin, accumulated in trans form with known photoprotective properties. This isomer can be photoisomerized to cis-Urocanic acid, a mediator of the cutaneous immunosuppression. In this work, the HPLC separation was achieved on a Cyclobond I TM 2000 β-Cyclodextrin column. The mobile phase was a 15:85v/v solution of phosphate buffer-acetonitrile in an isocratic elution, at a flow rate of 3 mL min. The diode array detector was operated at 276 nm, and column temperature was adjusted at 20°C. The urocanic acid isomers peaks are well resolved and free of interference from matrix components. The extraction and analytical method developed in this work allows the quantification of urocanic acid isomers with linearity and precision, establishing a simple and fast method of urocanic acid isomer quantification extracted from skin.