Optimization of Residual Solvent Determination of Egg Yolk Lecithin in Chinese Pharmacopoeia

OBJECTIVE To establish a headspace gas chromatography method for the determination of five kinds of residual solvents in egg yolk lecithin, such as petroleum ether, ethanol, diethyl ether, acetone and n-hexane. Using gas chromatography-mass spectrometry technology, the mass spectrometry retrieval data for other volatile impurities in the sample were combined to identify the structure. METHODS GC conditions were column: DB-624UI capillary column(60 m× 0.25 mmm 1.4 μm), the column temperature was raised by program; Detector: flame ionization detector; detector temperature: 250 ℃; Split ratio: 20∶1. GC-MS conditions were GC conditions: the carrier gas was helium, the remaining conditions accorded with GC conditions above. MS conditions were ion source temperature: 230 ℃; the interface temperature was set at 230 ℃; using electron impact inoization; EI energy: 70 eV; scanning mode: Q3Scan mode; scan range: m/z 45-500; detection time: 7.00-28.50 min. RESULTS The 5 residual solvents tested were completely separated, other volatile impurities in the sample had no influence on the 5 residual solvents. The linear relationship was good in the concentration range(r>0.999); limit of detection were (0.003-0.13)μg·mL^-1, limit of quantitation were (0.017-0.21)μg·mL^-1; average recoveries were 93.74%-104.31%; accuracy and repeatability were <5%. CONCLUSION The method is simple, highly sensitive and reproducible, it can be used to determine the residual solvents in egg yolk lecithin.