[Determination of beta-carotene in Fructus lycii by nonaqueous reversed-phase high performance liquid chromatography].

A simple, rapid and accurate quantitative method was established for the determination of beta-carotene in Fructus lycii by isocratic nonaqueous RP-HPLC. Separation was obtained by using Shim-Pack CLC-ODS column (6 mm i.d. x 150 mm, 5 microm) and mobile phase of methanol/ethyl acetate (50:55, V/V) with flow rate of 1 mL/min. The eluates were monitored with UV/VIS detector at 448 nm. The retention time for beta-carotene was 7.33 min. The calibration curve was linear in the range of 1.0-5.0 mg/L with r=0.9998. The average recovery for beta-carotene was 97.1% with a coefficient of variation of 1.9%. The content of beta-carotene in Fructus lycii from different areas was also determined.