2021 FDA Science Forum
A “Dilute-and-Shoot” UPLC/MS/MS Method for Simultaneous Determination and Confirmation of Eleven Mycotoxins in Distillers Dried Grains with Solubles
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Contributing OfficeCenter for Veterinary Medicine
Abstract
Background
Distillers dried grains with solubles (DDGS) is the by-product of the corn-based industrial ethanol production. DDGS contains rich nutrition for food animals and has become a mainstream feed ingredient since mid-2000’s. However, natural contamination of mycotoxins is a known and recurring problem that affects product quality and animal health. In the U.S., the FDA has set up systematic residue levels for selected mycotoxins of high animal health concerns in feeds or feed ingredients, depending on animal species, developmental stages and intended use. Currently there is no method that can simultaneously quantify the most important 11 mycotoxins (aflatoxins B1/B2/G1/G2, fumonisins B1/B2, deoxynivalenol, zearalenone, ochratoxin A, T-2 and HT-2 toxins) in DDGS.
Purpose
To develop and validate an analytical method that can quantify eleven mycotoxins of interest in DDGS, and simultaneously confirm their chemical identities.
Methodology
DDGS samples are extracted with acetonitrile/water under acidic condition. Two aliquots from the crude extract are further diluted by either 400-fold with solvent or 16-fold (pH adjusted to 7.5) with buffer for analysis of two sub-sets of these mycotoxins. Isotope-labeled analytes are added in the end for accurate quantitation. Ultra-High-Pressure Liquid Chromatography Tandem Mass Spectrometry is used to detect the 11 mycotoxins in the sample extracts.
Results
The linear quantitation range for each mycotoxin has been set up to embrace the respective residue level of concern. Overall, accuracies for these analytes at each of three fortification levels range from 70.7% to 100%, with corresponding relative standard deviations between 1.4% and 10.5%.
Conclusion
This method has been successfully validated in our lab to meet the performance criteria by pertinent FDA guidelines for regulatory quantitative method. Extensive robustness testing has also been conducted.
Public Health Impact
FDA regulates harmful chemical substances in feed and feed ingredients including DDGS. This work provides a sensitive, selective, and high through-put analytical method to monitor 11 high-priority mycotoxins in DDGS, to enhance the agency’s capacity to protect the health of food animals.
