A rapid, sensitive method for accurate determination of the lecithin/sphingomyelin ratio by thin-layer chromatography...

A highly reproducible thin-layer chromatographic procedure has been developed for accurate determination of the lecithin/sphingomyelin ratio. Two interfering compounds, phosphatidyl inositol and phosphatidyl serine, have been investigated and eliminated by adsorption onto DEAE-cellulose. A uniform fluorescence staining procedure employing 2',7'-dichlorofluorescein has been developed. Accurate quantitation was performed by direct measurement of the reflected fluorescence intensity of the lecithin and sphingomyelin fluorophore spots with a spectrofluorometer equipped with a thin-layer scanning attachment. Stability and reproducibility studies are reported.