QUANTITATIVE STUDY OF THE STRATUM CORNEUM LIPID CLASSES BY NORMAL PHASE LIQUID CHROMATOGRAPHY: COMPARISON BETWEEN TWO UNIVERSAL DETECTORS

The stratum corneum owns a barrier function, which can be altered by a modification of its lipid composition. In this work, a new simple method was developed in normal phase liquid chromatography to separate the three major lipid classes of the stratum Corneum, fatty acids, ceramides, and cholesterol. A quantitative investigation was carried out, comparing an internal normalisation and an external standardisation with two universal detectors: an evaporating light scattering detector and a charged aerosol detector, the Corona. The study points out the fact that the external standardisation is suitable for a quantitative study of the different lipid classes, using a representative standard for each class. Moreover, the use of the Corona is more adapted for further investigation, due to a better repeatability, accuracy, and precision. A test made on a lipid extract from the forearm of volunteers shows that the present method is appropriate for biological extract analysis.