Abstract:

Objective: To establish a method for the quality analysis of lecithin extracted from flax by high performance
thin layer chromatography (HPTLC). Methods: Test samples of lecithin and phosphatidylcholine standard were dissolved
separately in chloroform-methanol (3:2, V/V) before analysis by HPTLC. The developing system consisted of chloroform,
methanol and water (65:25:4, V/V). The effects of chromogenic agents, developing systems, amounts of spotted sample,
thin layer chromatography plates, temperature and relative humidity on the separation of each component in sample were
investigated. Under the best chromatography condition, the lecithin in the sample and the standard were developed, and
the peak area of phosphatidylcholine was scanned. A standard curve was established and phosphatidylcholine in sample
was quantified by an external standard method. Results: The separation of each component in sample was suitable for
qualitative analysis. The average content of phosphatidylcholine in lecithin sample was 63.33% with plate-to-plate and
within-plate precision (relative standard deviation, RSD) of 1.82% and 3.73%, respectively, and stability (RSD) of 1.60%,
and the average recovery was 98.5%. Conclusion: The method is rapid, accurate and reproducible, which can provide a new
technical reference for the quality analysis of lecithin.

Key words: lecithin, high performance thin layer chromatography, phosphatidylcholine, quality analysis