Analysis of commercial ceramides by non-aqueous reversed-phase liquid chromatography with evaporative light-scattering detection

This paper describes the development of a chromatographic system for analysis of commercial ceramides structurally similar to those found in the stratum corneum. The ceramides used in this study contain different amine bases (phytosphingosine, sphingosine and dihydrosphingosine) and fatty acids of different chain lengths and with different functional groups (hydroxylated and unsaturated). Non-aqueous reversed-phase (NARP) liquid chromatography with evaporative light-scattering detection (ELSD) were the techniques chosen in accordance with the nature of the ceramides. The eluent strength and the potential selectivity of different organic solvents were investigated. On a Cls-bonded silica, the most promising chromatographic conditions employed a gradient from ACN-THF, 95:5, to ACN-THF-PrOH, 35:5:60, in 15 min with a constant concentration of TEA (10 mM) and a stoichiometric amount of formic acid.