[Determination of sennoside B, sennoside A and physcion in slimming health foods].

OBJECTIVE: To establish a quantitative analysis method for sennoside A, sennoside B and physcion by ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). METHODS: The sample was extracted by methanol-2 mmol/L ammonium formate(9∶1) at 40 ℃ for 1 h. The separation was performed using Agilent Eclipse Plus C_(18 )(2. 1 mm × 50 mm, 1. 8 µm) column with gradient elution. The mobile phase was consisted of 0. 1% formic acid and methanol. Qualitative and quantitative analysis was conducted with an electrospray ionization source operated in the negative ionization(ESI~-) mode and multiple reaction monitoring(MRM) mode. RESULTS: The linear range of three compounds were from 0. 1 to 10 µg/mL with the correlation coefficients(r) above 0. 995. The spiked recoveries were in the range of 81. 9% to 114. 5% at the concentrations of 0. 02, 0. 15 and 1. 60 mg/g with relative standard devisions(RSDs) ranged from 0. 30% to 3. 43%(n=6). The detection limits of sennoside A and sennoside B were 1. 2 µg/g. The detection limit of physcion was 2. 4 µg/g. Sennoside A, sennoside B or physcion were detected in 19 out of 40 batches of samples. The content of sennoside A ranged from 0. 184 to 6. 33 mg/g and the content of sennoside B ranged from 0. 202 to 7. 23 mg/g. The content of physcion ranged from 0. 042 to 0. 79 mg/g. CONCLUSION: The method is simple, accurate and suitable for the determination of sennoside A, sennoside B and physcion.

[Theanine, EGCG and caffeine determinated by HPLC].

OBJECTIVE: A high-performance liquid chromatography (HPLC) method was developed for the determination of theanine in puer tea without derivatization and HPLC for EGCG and caffeine with ingredient elution system was put forward. METHODS: The theanine in the tea was extracted with water. The EGCG and caffeine was extracted with water: ethanol (3:7) by ultrasonic oscillation. After centrifugation, the extract was analyzed by HPLC-PDAD with a C18column and at the flow rate 1 ml/min. The theanine was determinated with 5 mmol/L SDS-acetonitrile mobile phase system (72:28), and both EGCG and caffeine with 0.05 mmol/L KH2PO4-methonal mobile phase system (80:20). RESULTS: The calibration of three ingredients was in good linearity. The recovery range is 85%-110%. The RSD is less than 10%. CONCLUSION: The method is accurate and stable.