Premium
A Comparison of Chemical and Densitometric Determination of Lecithin/Sphingomyelin Ratios on Thin‐layer Chromatograms
Author(s) -
Ekelund Laila,
Enhörning Göran
Publication year - 1976
Publication title -
international journal of gynecology and obstetrics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.895
H-Index - 97
eISSN - 1879-3479
pISSN - 0020-7292
DOI - 10.1002/j.1879-3479.1976.tb00558.x
Subject(s) - densitometry , lecithin , chromatography , sphingomyelin , precipitation , medicine , acetone , chemistry , biochemistry , cholesterol , physics , meteorology
The value of amniotic fluid lecithin to sphingomyelin ratio (L/S ratio), determined by phosphorus quantitation, was compared with that obtained by densitometry. A good correlation was found, but the densitometry values were 25–30% lower. Acetone precipitation was included in the densitometry analysis, but not in the assay based on phosphorus quantitation. Since all the sphingomyelin was precipitated, but only a portion of the lecithin, the precipitation procedure could explain the lower densitometry values. It was concluded that the faster densitometry technique was acceptable, but should not include acetone precipitation. If it does, the value will be approximately 25–30% lower.