Determination of the aflatoxin AFB1 from corn by direct analysis in real time-mass spectrometry (DART-MS)

Abstract

Direct analysis in real time (DART) ionisation coupled to a high-resolution mass spectrometer (MS) was used for screening of aflatoxins from a variety of surfaces and the rapid quantitative analysis of a common form of aflatoxin, AFB1, extracted from corn. Sample preparation procedure and instrument parameter settings were optimised to obtain sensitive and accurate determination of aflatoxin AFB1. 84:16 acetonitrile water extracts of corn were analysed by DART-MS. The lowest calibration level (LCL) for aflatoxin AFB1 was 4 μg kg^–1. Quantitative analysis was performed with the use of matrix-matched standards employing the ¹³C-labelled internal standard for AFB1. DART-MS of spiked corn extracts gave linear response in the range 4–1000 μg kg^–1. Good recoveries (94–110%) and repeatabilities (RSD = 0.7–6.9%) were obtained at spiking levels of 20 and 100 μg kg^–1 with the use of an isotope dilution technique. Trueness of data obtained for AFB1 in maize by DART-MS was demonstrated by analysis of corn certified reference materials.

Graphical Abstract

Keywords:

• mass spectrometry
• mycotoxin
• aflatoxin

Acknowledgements

The authors gratefully acknowledge helpful suggestions from Elizabeth Crawford and Thomas Maragos for drafting the schematic of the DART stage in Figure 1.

Funding

The authors would like to thank the Ministry of Agriculture of the People’s Republic of China [grant number 2011-G5(3)] and Science and Technology Department of Henan Province [grant number 112101110400] for supporting this work.