RESUMO
OBJECTIVE: To determine alpha-linolenic acid and linoleic acid in extract of Portulaca oleracea L. by high performance liquid chromatography (HPLC). METHODS: The determination was done with a Shim-pack CLC-ODS (250 mm x 4.6 mm, 5 microm) and a DIKMA Easyguard C18 (10 mm x 4.6 mm). Elution was employed with the mobile phase of methanol-acetonitrile-0.5% phosphonic acid (60:22:18) at flow rate of 1.1 ml/min. Column temperature was 26 degrees centigrade. Detection wavelength was 210 nm. Injection volume was 25 microl. RESULTS: The standard curves of alpha-linolenic acid and linoleic acid were linear in the range 0.016 2 to 0.194 4 mg/ml and 0.016 9 to 0.203 0 mg/ml, respectively. The regression equations were A=2.915 8 x 10(7) C+12,250.9, r=0.999 9 and A=1.366 4 x 10(7) C-9,759.39, r=0.999 9, respectively. The average recovery rates were 100.5% and 100.8%, respectively. CONCLUSION: The present method (HPLC) may be considered to be reliable and simple for the determination of alpha-linolenic acid and linoleic acid in extract of Portulaca oleracea L.