Liquid chromatographic determination of St. John's wort components in functional foods.
A method was developed for determination of St. John's wort marker compounds hypericin, pseudohypericin, hyperforin, and adhyperforin in functional foods. Solid-phase extraction provided analyte extraction and significant sample cleanup prior to analysis using liquid chromatography (LC) with UV and fluorescence detection. In addition to quantification using LC-UV, confirmation was made with electrospray ionization LC mass spectrometry (LC/MS). Several commercially available tea and drink products claiming to contain St. John's wort were tested. Recoveries ranged from 51 to 98% for the liquid samples. Comparison of the concentrations in 4 St. John's wort teas showed a variation in analyte concentration (1044-10 ng/mL marker compounds in brewed tea) and composition. No marker compounds were found in the beverages, indicating possible decomposition of the marker compounds caused by low pH and/or exposure to light. A solvent extraction procedure was developed for analysis of the marker compounds from solid samples. Analytes were detected at low parts per million, with an average recovery of 75%. No St. John's wort components were found in the 2 solid functional food samples analyzed.
de Jager
Lowri S
LS
U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5100 Paint Branch Pkwy, College Park, MD 20740, USA. Ldejager@cfsan.fda.gov
Perfetti
Gracia A
GA
Diachenko
Gregory W
GW
D000873:Anthracenes; D001628:Beverages / Q000032:analysis; D001643:Bridged Bicyclo Compounds / Q000032:analysis*; D002853:Chromatography, Liquid; D005504:Food Analysis; D010569:Perylene / Q000031:analogs & derivatives* / Q000032:analysis*; D010696:Phloroglucinol / Q000031:analogs & derivatives* / Q000032:analysis*; D013729:Terpenes / Q000032:analysis*
D000873:Anthracenes; D001643:Bridged Bicyclo Compounds; D013729:Terpenes; C423123:adhyperforin; D010569:Perylene; C004965:hypericin; D010696:Phloroglucinol; C056602:pseudohypericin; C001654:hyperforin