Evaluation of non-polar bonded-phases for the clean-up of maize extracts prior to aflatoxin assay by HPTLC

Abstract

The ability of a PH non-polar bonded phase to extract aflatoxin from aqueous solutions (1% v/v) containing 5, 10, 20 and 30% acetone, acetonitrile or methanol was determined. The amount of aflatoxin extracted by the cartridge from aqueous solutions remained almost constant (97–102%) as the concentration of methanol increased, but decreased rapidly when the amount of acetone or acetonitrile increased beyond 10%. Examination of the ability of a number of bonded phases (C2, C8, C18, CH and PH) to extract aflatoxin from aqueous methanol extracts of maize revealed that the PH bonded phase was the most efficient. Aflatoxin is eluted from the cartridge by chloroform (7 ml). An additional clean-up step involving bi-directional development was required when quantifying low levels of aflatoxin in maize by HPTLC.