HPLC Analysis: Aflatoxins in Herbs, Spices, Peanuts, and Grains
Aflatoxins are naturally occurring mycotoxins that are produced by the fungus Aspergillus, which grows in soil and decaying vegetation and can contaminate food crops such as peanuts, grains, dried nuts and fruit. In sufficient quantities, aflatoxins are highly toxic and carcinogenic to human health, in particular, the health of children and as a result is regulated by many countries globally.
The European Commission has set maximum levels for aflatoxin B1 between 2.0 and 8.0 μg/kg and for the sum total of all four types of this toxin between 4.0 and 15.0 μg/kg in nuts, groundnuts, grains, and dried fruits. The U.S. Food and Drug Administration (US FDA) has set action levels (levels where the FDA will take legal action to remove products from the market) of 20 ppb (μg/kg) for the sum total of the four types of aflatoxins in foods such as corn, peanuts, brazil nuts, and pistachios as well as other foods.
The US FDA Guidance Compliance document offers more details on the regulations.
In this blog post, I am pleased to feature two methods developed by a customer, and one by our applications labs.
Analysis of Aflatoxins in Herbs and Spices
Recently, Pickering Laboratories--one of our customers--presented a poster at the 2011 AOAC meeting on the analysis of aflatoxins in herbs and spices. The poster titled, Clean up and Analysis of Aflatoxins and Ochratoxin A in Herbs and Spices, presents a simple, sensitive and robust HPLC analytical method.
Analysis of Aflatoxins in Peanuts and Peanut Butter
In addition, Pickering Laboratories has also published a Method Abstract, MA 215, Clean-Up and Determination of Aflatoxins in Peanut and Peanut Butter, which discusses a simple, sensitive and robust HPLC analytical method with post-column photochemical derivatization and fluorescence detection.
Analysis of Aflatoxins in Grains or Food
For this analysis, our Germering (Germany), Salt Lake City (USA), and Amsterdam (The Netherlands) teams developed a method titled, Fast and Effective Determination of Aflatoxins in Grains or Food Using Accelerated Solvent Extraction followed by HPLC. This method offers several advantages over the traditional method of soxhlet extraction (Wikipedia page) and sample clean-up using solid-phase extraction (SPE). Here, an accelerated solvent extraction (ASE) system is used followed by on-line SPE-LC for the analysis of aflatoxins in corn and almonds. The ASE system uses high temperatures during extraction to speed-up the extraction process, while incorporating high pressure to maintain the solvents in their liquid state.
Do let us know in the comments box below if you are looking to test aflatoxins in matrices not mentioned in this post. We look forward to your comments.