ABSTRACT
Objective To develop a liquid chromatography-mass spectrometry (LC-MS) method for the determination of S-allyl-L-cystein in extraction of garlic. Methods A LC-MS method was established on a ZORBAX Eclipse XDB-C8(4.6 mm×250 mm, 5 μm)column with the mobile phase consisting of 1‰ formic acid water-methanol (95:5), flow rate of 0.8 mL/min and detection with post-column splitting. The split ratio was 2:1, column temperature was set at 25 ℃. The mass spectrometer equipped with ESI and the ion source was operated in negative mode. The dry gas flow was 10.0 L/min, the nebulizer pressure was 30 psig, and the vaporizer temperature was 350 ℃. SIM detector, S-allyl-L-cystein m/z 160 and S-allyl-L-cystein sulfoxide m/z 176. Results The calibration curves showed good linearity in the range of 0.062 5-2 μg/mL of S-allyl-L-cystein. The detection limit was 0.01 μg/mL. The within-day RSD was 4.11% and the day-to-day RSD was 4.49%.The average recovery for S-allyl-L-cystein was 101.63%. Conclusions The method is simple and accurate. It is adapted to determine and analyze S-allyl-L-cystein in extraction of garlic and the average content of S-allyl-L-cystein is 0.514 μg/mg.