Improving quantitative analysis of phosphatidylcholine in lecithin using an HPLC-evaporative light-scattering detector

The Health Functional Food Code uses a high-performance liquid chromatography (HPLC) refractive index detector (RID) to analyze phospholipids, the main ingredients in lecithin. However, RIDs have disadvantages of low sensitivity, high limits of detection (LOD) and quantification (LOQ), and complicated sample preparation. An evaporative light scattering detector (ELSD) with excellent sensitivity was used in this study. Validation showed high resolution, low LOD (22.64-32.57 μg/mL) and LOQ (68.60-98.68 μg/mL), and high reproducibility (98.15-104.29%). Uncertainties (95% confidence interval, k=2) were found to be 120.53±12.15 mg/g (soy lecithin) and 406.59±35.26 mg/g (egg yolk lecithin). The percent uncertainty of the measured concentrations (10.04% (soy lecithin) and 8.68% (egg yolk lecithin)) met the standards (11% or less) established by the European Union. Therefore, this HPLC-ELSD method shows excellent applicability for analyzing phosphatidylcholine in lecithin.