Submitted to: Mycotoxin Protocols
Publication Type: Book / Chapter
Publication Acceptance Date: 3/8/2000
Publication Date: N/A
Interpretive Summary: Cyclopiazonic acid (CPA) is a mycotoxin produced by several species of fungi in the genera Aspergillus and Penicillium. It has been found as a natural contaminant of various commodities including corn, peanuts, cheese, and millet. Analysis of commodities for the presence of CPA has been difficult because of laborious cleanup measures that extracts require prior to the quantitative step. In this study a much simpler cleanup procedure was utilized in conjunction with liquid chromatography (LC) to provide sensitive and reproducible analyses of peanuts for CPA. The cleanup procedure uses a column packed with antibodies specific for CPA to isolate the CPA from an extract while interfering impurities are washed through. CPA is then eluted from the column and can be easily determined by LC analysis. The limit of detection of CPA in peanuts was 2.5 ppb and recovery of CPA ranged from 84 to 91%.
Technical Abstract: A method was developed for the determination of the mycotoxin, cyclopiazonic acid (CPA), in peanuts. The method relies on liquid chromatographic (LC) quantitation after cleanup of extracts on an immunoaffinity column. Peanuts were extracted with 70:30 methanol/1% sodium bicarbonate in water and filtered, and the extract was applied to an immunoaffinity column containing a monoclonal antibody with high affinity to CPA. After washing extract impurities through the column with 15 mL of water and 2 mL of 70:30 methanol/water, CPA was eluted from the column with 2 mL of methanol. An LC system was used to quantify the CPA with detection by a diode array detector. Recoveries of CPA from peanuts spiked at 10 and 100 ng/g were 90.8 and 83.7%, respectively, with respective coefficients of variation of 7.6 and 6.6%. The limit of detection was 2.5 ng/g. The method was used to analyze peanuts grown under late-season drought conditions, and natural contamination of peanuts with CPA was found ranging from 3.0 ng/g in jumbo sized peanuts to 8105.0 ng/g in damaged seed.