Use of ion-exchange chromatography coupled with TLC-laser scanning densitometry for the quantitation of fumonisin B1

A simple TLC-Laser scanning densitometric (TLC-LSD) method was developed for the quantitation of fumonisin B1 (FB1) isolated from solid media cultures (corn) and liquid media cultures of toxigenic Fusarium moniliforme strains (F. moniliforme MRC 826, F. moniliforme 4223 and F. moniliforme 2927)). FB1 was isolated from the cultures by solvent extraction (methanol:water, 3:1) and purified in a single step by ion-exchange chromatography using Dowex-1. FB1 in the purified extracts was detected by TLC analysis using p-anisaldehyde as a post-chromatographic derivatizing agent. The major toxin identified was FB1 (Rf 0.51) along with traces of FB2 (Rf 0.57) and FB3 (Rf 0.60) based on their comparison with the reference standard fumonisins. The sensitivity of the TLC-LSD method for the quantitation of FB1 was found to be 500 ng g−1. The linear regression analysis performed for the quantitation of FB1 by the TLC-LSD method showed a correlation coefficient (r) value of 0.9. Spiking studies revealed the recovery of standard FB1 (5 and 10 μg g−1) loaded on to Dowex-1 in the range of 87–96%. The purity of FB1 purified from the cultures was determined by the two-dimensional TLC analysis. Two-dimensional TLC-analysis of the purified FB1 revealed the purity to be greater than 85%. The method developed may find wide application in the environmental monitoring of the FB1 contaminations in the various agricultural commodities and screening fumonisin producing toxigenic strains of F. moniliforme.