Effect of Matrix Clean-Up for Aflatoxin Analysis in Corn and Dried Distillers Grains

A Mcdaniel,A E Brown,K.L Armbrust,W.E Holmes,D.L Sparks

doi:10.4236/nr.2011.24032

Abstract

Aflatoxins are a group of highly carcinogenic mycotoxins that contaminate a wide variety of agricultural crops and have a detrimental economic impact on industries, such as corn and ethanol production. They are regulated by the FDA, and therefore, rapid, reliable cleanup techniques with low detection limits are needed for aflatoxins in a wide array of matrices. In this study the effect of using an immunoaffinity column versus simple filtering as a cleanup was tested for afltoxins extracted from corn and Dried Distillers Grains (DDG). The aflatoxins were analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS). The use of an immunoaffinity column resulted in greater signal-to-noise ratios (S/N), S/N of 70 vs. S/N of 5 for corn, as well as fewer non-target peaks in the analysis. Recoveries of aflatoxin using immunoaffinity ranged from 40% to 104.5% (spiked substrate) and 49% to 120% (spiked extract) while percent recoveries of filtered samples ranged from 84% to 119% (spiked substrate) and 88% to 119% (spiked extract). This comparison study showed that filtering is acceptable for small sample sets or where rapid throughput is needed. However, for larger sample sets a more stringent cleanup method is necessary to ensure instrument performance.

Highlights

Aflatoxins are a group of mycotoxins that are produced by several fungal species including the genus Aspergillus, most notably A. flavus and A. parasiticus [1,2]
While baseline separation of the aflatoxins was not achieved, coelution of compounds is acceptable when using tandem mass spectrometry as this technique allows for definitive identification [20,21] and has been used in such fields as proteomics [22], pesticide analysis [23], and forensics [24]
The mass spectrometer is capable of detecting multiple ions simultaneously, which are unique to each analyte

Summary

Introduction

Aflatoxins are a group of mycotoxins that are produced by several fungal species including the genus Aspergillus, most notably A. flavus and A. parasiticus [1,2]. A. flavus is a ubiquitous fungus that has been found worldwide. It is a host pathogen known to infect such crops as corn, peanuts, and cotton [2]. This creates a regulatory issue with selling contaminated food products as aflatoxin B1 has been found to be a potent carcinogen [3]. The FDA has set action levels for aflatoxins at 20 ppb (total aflatoxins) for foods designated for human consumption [4]

Methods

Results

Conclusion