We have investigated whether fluorimetric determination of the lecithin/sphingomyelin ratio is feasible after HPLC. We found that the saturated phospholipid, dipalmitoyl lecithin, which is secreted by the fetal lung, and which cannot be detected by ultraviolet spectrophotometry, can be determined fluorimetrically. For this purpose we have added the fluorescence-enhancing substance, 1,6-diphenyl-1,3,5-hexatriene to the effluent. With the aid of a continuous-flow system we showed that the method can be used for a rapid assay of the ratio of these phospholipids in amniotic fluid.
References
1.
GluckLKulovichMVBorerRCDiagnosis of the respiratory syndrome by amniocentesis. Am J Obstet Gynecol1971; 109: 440–5.
2.
VerhoevenAGLMerkusHMWM. Procedures for the determination of the L/S ratio in amniotic fluid with a new detection reagent. Clin Chim Acta1974; 53: 229–32.
3.
JungalwalaFBEvansJEMcCluerRH. High performance liquid chromatography of phosphatidylcholine and sphingomyelin with detection in the region of 200 nm. Biochem J1976; 155: 55–60.
4.
KaduceTLNortonKCSpectorAA. A rapid isocratic method for phospholipid separation by HPLC. J Lipid Res1983; 24: 1398–1403.
5.
BrownBJGabertHAStencheverMA. Respiratory distress syndrome, surfactant biochemistry and aceleration of fetal lung maturity: A review. Obstet Gynecol Survey1975; 30: 71–90.
6.
KaltarantaJRBessmanSP. Determination of phospholipids by a combined liquid-chromatograph-automated phosphorus analyzer. Anal Chem1981; 52: 1232–5.
7.
YandrasitzJRBerryGSegalS.High performance liquid chromatography of phospholipids: Quantitation by phosphate analysis. Analyt Biochem1983; 135: 239–43.
8.
LondonEFeigensonGW. A convenient and sensitive fluorescence assay for phospholipid vesicles using diphenylhexatriene. Analyt Biochem1978; 88: 203–11.
9.
GebhardtDOE. The acetone precipitation step is needed in determining the L/S ratio of amniotic fluid. Clin Chem1983; 29: 214.
10.
BriandRLHaroldSBlassKG. HPLC determination of the L/S ratio in amniotic fluid. J Chromatogr1981; 223: 277–84.
