Accurate measurement of lecithin and sphingomyelin after ultra-rapid chromatographic separation

The use of small sandwich chambers containing silica-gel-impregnated glass fibre sheets allows chromatographic separation of lecithin and sphingomyelin in 3 minutes, compared with 45 minutes on conventional silica gel media. Quantitation by measuring the areas of the phospholipid spots after staining with a molybdate stain or 8-anilino-1-naphthylamino sulphonic acid was found to be accurate and more convenient than densitometry. Although slight inaccuracies may be caused by lack of resolution from certain phospholipids, this was not found to be a problem in amniotic fluid analyses as they are either absent or present only in trace quantities. The speed of the technique makes it particularly useful for clinical purposes.