Contribution to liquid chromatographic analysis of cutaneous ceramides

Ceramides constitute the major group of lipids in the Stratum Corneum where they play a crucial role in maintaining the water permeability barrier of the mammalian epidermis. Cutaneous ceramides are highly heterogeneous in st ructure. Consequently commercial standards of all these molecules are not a vailable and no simple analytical system supports this magnitude at this ti me. Our work suggests a strategy, which offers the possibility of having th e first simple tool for ceramide structural identification in the absence o f a ceramide standard. The ceramide separation is done in NARP (non-aqueous reverse phase) liquid chromatography and the ceramide structural identific ation in GC/MS (gas chromatography / mass spectrometry). The correlation be tween these two methods establishes the retention behaviour of ceramides. T his retention has been shaped into abacuses. This approach is based on various theories: the linear progression of t'(R) in a linear gradient, methylene selectivity and the incrementation on homo logous series. This approach by modelisation has the advantage of being com pleted by iterations each time a new structure is available and without hav ing to carry out the optimisation of the system again.