J. Dupuy et al., DETERMINATION OF FUMONISIN B-1 CORN BY INSTRUMENTAL THIN-LAYER CHROMATOGRAPHY, JPC. Journal of planar chromatography, modern TLC, 6(6), 1993, pp. 476-480
An instrumental TLC method has been developed for quantification of fu
monisin B-1 (FB1), a mycotoxin from Fusarium moniliforme (Sheldon), in
corn. Samples of ground corn free from FB1 were spiked at different l
evels (5 to 350 mg/kg) with crude FB1 extracts. After extraction and p
urification by solid phase extraction, FB1 was separated by 2-step TLC
and quantified by scanning densitometry after postchromatographic der
ivatization. The suitability of various solvent systems for dissolutio
n of FB1 was studied, as was their influence on spotting. Two reagents
, p-anisaldehyde and ninhydrin were compared in terms of sensitivity,
specificity, and stability of detection, the higher response and lower
limit of detection being obtained with p-anisaldehyde. A delay of 30
min. between derivatization and quantification minimized the error res
ulting from response decay. The repeatability of the calibration curve
fluctuated from 2 to 10 % (RSD) and the limit of detection was 51.1 n
g for standards and 100 ng for extracts. The limit of quantification w
as 100 mg/kg (ppm) without purification and 5 ppm after purification.
Recoveries were greater than 80 % for levels in excess of 25 ppm and 6
7.6 % at the limit of quantification (5 ppm). The main source of error
was the error of spotting: +/-4.02 % (RSD). Intraplate and interplate
variation were +/-4.98 % and +/-6.50 % (RSD), respectively. The techn
ique appeared adequate for detection of FB1 in foodstuffs at the maxim
um recommended level (5 ppm).