Negative Ion Chemical Ionization Mass Spectrometric Method for Confirmation of Identity of Aflatoxin B,: Collaborative Study

Abstract

An interlaboratory study of a negative ion chemical ionization mass spectrometric (MS) confirmation procedure for aflatoxin B1 was conducted in laboratories in the United States, England, and West Germany. Twelve partially purified, dry film extracts from naturally and artificially contaminated roasted peanuts, cottonseed, and ginger root containing varying quantities of aflatoxin B1 were distributed to the participating laboratories. The extracts required additional cleanup before MS analysis, using either an acidic alumina column and preparative thin layer chromatography (TLC) or a 2-dimensional TLC procedure. Recovery of purified aflatoxin B1 was influenced by the degree of recovery of sample from acid alumina and/or the TLC plate and incomplete elution of aflatoxin Bt from silica gel. Factors affecting MS confirmation included the purity and recovery of aflatoxin and MS instrument sensitivity. Aflatoxin Bi identity was confirmed in 19.5, 90.9, and 100% of samples containing <5,5-10, and >10 ng aflatoxin B1/g product, respectively, by solid probe introduction using full mass scans. The MS method has been adopted official first action.

Rapid, Non-Destructive Selection of Peanuts for High Aflatoxin Content by Soaking and Tandem Mass Spectrometry

“…Several reports in the literature describe the analysis of aflatoxins in complex mixtures using mass spectrometry ( − ). Tandem mass spectrometry (MS−MS) was chosen for this project because of its ability to reduce interference.…”

A Review: Sample Preparation and Chromatographic Technologies for Detection of Aflatoxins in Foods

“…The procedure required a large on plate mass of aflatoxin B 1 , yet it did not work for other aflatoxins. Attempts to couple TLC with mass spectrometry for more specific identification were reported by Haddon et al [181,182], Brumley et al [183], Park et al [184] and Tripathi et al [185]. However, aflatoxins were unable to be directly analyzed by MS requiring extensive clean-up steps to remove aflatoxins from the plate and purified prior to MS analysis.…”

Pesticide analysis in food by MS

“…However, when probe samples are used for confirmation, gross interference can occur. In the case of confirmation of aflatoxin B, in peanuts under NCI, Park and co-workers argued that although the three ions representing the compound (m/z 297, 311, and 312) were present in the correct relative abundance ratios (Figure 2), they could be fragment ions from higher molecular weight compounds (11). They stated that when the interfering ions constitute more than 20% of the total intensity of the mass spectrum, confirmation cannot be deduced in spite of the presence of the three ions at the correct relative abundance ratios.…”