Determination of Aflatoxins by Liquid Chromatography Coupled to High-Resolution Mass Spectrometry

The most common mycotoxins are aflatoxins (AFs), which are produced by strains of various species of molds in the genus Aspergillus (A. flavus, A. parasiticus, A. nomius and A. tamarii) and can grow on many foods, mainly peanuts, maize and cottonseed. AFs are currently considered to be the most hazardous mycotoxins to health, in particular because of their hepatocellular carcinogenic potential. The main aflatoxins are B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2) although many other derivatives have been described. In addition, animals consuming contaminated feeds are able to metabolize them by hydroxylation in a certain position, yield for example aflatoxin M1 (AFM1) and aflatoxin M2 (AFM2) from AFB1 and AFB2, respectively. Nowadays, only the four main AFs and one hydroxylated metabolite (AFM1) are routinely analyzed. High resolution mass spectrometry (HRMS) using Orbitrap or time-of-flight (TOF) mass analysers is a trend for AFs determination, allowing to determine AFs and their derivatives for which there are no commercial standards available, in order to carry out metabolization studies, exposure assessment or monitoring modified AFs in food. The aim of this study is to show the recent trends in analytical methods based on LC-HRMS for determination of AFs.

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Determination of quaternary ammonium compounds in food products by the method of ultra-performance liquid chromatography/high resolution mass-spectrometry

Industrial laboratory Diagnostics of materials ◽

10.26896/1028-6861-2020-86-8-23-31 ◽

2020 ◽

Vol 86 (8) ◽

pp. 23-31

Author(s):

V. G. Amelin ◽

D. S. Bolshakov

Keyword(s):

Mass Spectrometry ◽

High Resolution ◽

Quaternary Ammonium ◽

High Resolution Mass Spectrometry ◽

Food Products ◽

Quaternary Ammonium Compounds ◽

High Resolution Mass ◽

Ammonium Compounds ◽

Resolution Mass

The goal of the study is developing a methodology for determination of the residual amounts of quaternary ammonium compounds (QAC) in food products by UHPLC/high-resolution mass spectrometry after water-acetonitrile extraction of the determined components from the analyzed samples. The identification and determination of QAC was carried out on an «UltiMate 3000» ultra-high-performance liquid chromatograph (Thermo Scientific, USA) equipped with a «maXis 4G» high-resolution quadrupole-time-of-flight mass spectrometric detector and an ion spray «ionBooster» source (Bruker Daltonics, Germany). Samples of milk, cheese (upper cortical layer), dumplings, pork, chicken skin and ground beef were used as working samples. Optimal conditions are specified for chromatographic separation of the mixture of five QAC, two of them being a mixture of homologues with a linear structure (including isomeric forms). The identification of QAC is carried out by the retention time, exact mass of the ions, and coincidence of the mSigma isotopic distribution. The limits for QAC detection are 0.1 – 0.5 ng/ml, the determination limits are 1 ng/ml for aqueous standard solutions. The determinable content of QAC in food products ranges within 1 – 100 ng/g. The results of analysis revealed the residual amount of QAC present in all samples, which confirms data of numerous sources of information about active use of QAC-based disinfectants in the meat and dairy industry. The correctness of the obtained results is verified by introduction of the additives in food products at a level of 10 ng/g for each QAC. The relative standard deviation of the analysis results does not exceed 0.18. The duration of the analysis is 30 – 40 min.

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