A method was established for underivatized @entity3689 determination in fermented beverage of plant extract. Samples were diluted with @entity1042 for five times, extracted by ultrasonic vibration for 30 min, and high-speed centrifuged for 15 min at 10,000 r/min. The supernatant was separated and detected by, high performance liquid chromatography-tandem mass spectrometry (HPLC- @entity15 / @entity15 ). The chromatographic column was Venusil ASB @entity6173 (250 mm x 4.6 mm, 5   m). The elution was performed at a flow rate of 0.5 mL/min using the mobile phases of @entity1042 - @entity1543 -water mixture. The @entity15 detector was set as follows: ion source voltage 3 kV, ion source temperature 150 t, solvent temperature 350 t, gas flow rate 800 L/h. The collision gas was @entity3503 with a pressure of 0.17 Pa. The quantitation analysis was carried out with peak area in extracted ion chromatograms. Good linearities were acquired in the range of 0.5-200   mol/L (r2 > 0.99) for the @entity1522 . The recoveries were between 86% and 110%. There were 16 @entity1522 in the fermented beverage of plant extract quantitatively analyzed. The method is simple, rapid, accurate and reliable in quantitative analysis of @entity3689 samples in the fields of pharmaceutical, food and natural products.

[Direct quantitative analysis of XXXX in fermented beverage of plant extract using high performance liquid chromatography-tandem mass spectrometry].

@entity1522 :: ('CHEBI:33709', 'Chemical') :: ['amino acids'] @entity1042 :: ('MESH:D000432', 'Chemical') :: ['methanol'] @entity6173 :: ('27241', 'Gene') :: ['C18'] @entity3503 :: ('MESH:D001128', 'Chemical') :: ['argon'] @entity3689 :: ('D000596', 'Chemical') :: ['amino acid'] @entity15 :: ('MESH:D009103', 'Disease') :: ['MS'] @entity1543 :: ('MESH:D019342', 'Chemical') :: ['acetic acid']
@entity1522 :: (CHEBI:33709,Chemical) :: ['amino acids']
