Mycotoxins

Certain fungi & mold commonly found on grain products have the capacity to form chemical substances that are harmful when eaten by humans or animals. These substances are called mycotoxins, a term derived from "myco" meaning fungus and "toxin" meaning poison.

Mycotoxins are usually associated with crops that have been stressed during the growth cycle or during storage. Such conditions include cool damp summers, late wet harvests, drought and environmentally stressful conditions and poor storage after harvests, even at moisture levels as low as 16%.

Mycotoxins may remain in food & feed long after the fungus that produced them has died; therefore, toxins can be present even when there are no visible signs of mold or fungus. A proactive monitoring program for agricultural commodities should always include testing for mycotoxins to ensure the safety of a product.

Our laboratories can test for a wide variety of mycotoxin tests including:

• Aflatoxins
• Aflatoxin M1 
• Fumonisins
• Mycotoxin Screen (Aflatoxin B1,B2,G1,G2; T-2 Toxin; Ochratoxin A)
• Ochratoxin A
• T-2 Toxin
• Vomitoxin (DON or Deoxynivalenol)
• Zearalenone (F-2 Toxin)

Methods of Mycotoxin Analysis

Enzyme-Linked Immunosorbent Assay (ELISA) Procedure

ELISA tests can be performed in shorter time periods than TLC or HPLC tests and provides relatively accurate screening results.  Several ELISA kits have AOAC or AOACRI approval. 

Elisa techniques are based on a coupling reaction between a specific mycotoxin and antibodies specific for those mycotoxins.  If an ELISA assay produces a positive result it should be confirmed using a TLC or HPLC procedure. 

Our laboratories offer a variety of ELISA tests including:   

• Aflatoxins 
• Fumonisins
• Ochratoxin 
• T-2 Toxin
• Vomitoxin
• Zearelenone (F-2 Toxin)

Thin Layer Chromatography (TLC)

TLC is one of the more accurate methods of testing samples for the presence of aflatoxin, vomitoxin, ochratoxin or T-2 Toxin.  This is a quantitative method and is AOAC approved.  

TLC methods are recommended for clients needing increased accuracy of results.  If positive results are found using an ELISA test it is recommended that a confirmatory test be conducted using TLC or HPLC methods. 

The following are detection limits for TLC methods for the following mycotoxins:

• Aflatoxin B1, B2, G1, G2  (Detection Limit of 2 ppb for each)
• T-2 Toxin (Detection Limit of 200 ppb)
• Ochratoxin A (Detection Limit of 10 ppb)
• Zearalenone (Detection Limit of 100 ppb)

A number of HPLC methods exist for analyzing aflatoxin, usually based on the AOAC approved method for corn and peanut butter.  These methods are capable of lower quantitation limits and usually show more specificity. 

HPLC methods are usually the most costly and turn-around time is normally longer than TLC or ELISA procedures.  There are also HPLC methods covering other mycotoxins as well.