Jf. Lawrence et al., Effect of temperature and solvent composition on extraction of fumonisins B-1 and B-2 from corn products, J AOAC INT, 83(3), 2000, pp. 604-611
Fumonisins B-1 and B-2 were extracted from naturally contaminated corn prod
ucts by using different extraction solvent compositions (methanol-water, ac
etonitrile-methanol-water, ethanol-water, and 100% water) and a range of te
mperatures from ambient to 150 degrees C. Ground samples of several corn pr
oducts and I rice sample were mixed with an adsorbent material (Hydromatrix
(TM)), and the fumonisins were extracted in 2 sequential 5 min static extra
ctions at various temperatures. The combined extracts were cleaned up and a
nalyzed by reversed-phase liquid chromatography with fluorescence detection
after o-phthaldialdehyde-mercaptoethanol derivatization, The results showe
d a clear influence of temperature and solvent composition on recovery of f
umonisins from some matrixes. With acetonitrile-methanol-water (1 + 1 + 2)
the quantity of fumonisins extracted from naturally contaminated taco shell
s almost tripled in going from 23 degrees to 80 degrees C, and increased by
another 30% when ethanol-water (3 + 7) was used as extraction solvent at 8
0 degrees C. Similar results were obtained with nacho chips. These effects
were less pronounced with cornmeal, and small differences due to temperatur
e and solvent composition were observed for corn flakes and rice. The ethan
ol-water extraction solvent combinations were specifically evaluated in an
effort to use the cheapest, least toxic, and most environmentally friendly
solvents for organic residue analysis. At 80 degrees C, ethanol-water combi
nations performed equally or better than methanol-water (8 + 2) or acetonit
rile-methanol-water (1 + 1 + 2), combinations which are commonly used for f
umonisin extractions. Even 100% water was successful for extracting fumonis
ins from the products, except for rice. However, increased amounts of water
created technical problems and required an increased amount of Hydromatrix
in the samples prior to extraction.