A high performance liquid chromatographic assay for the mycotoxin phomopsin A in lupin stubble

Abstract

An assay using high performance liquid chromatography to measure phomopsin A, the principal mycotoxin responsible for lupinosis is described. Samples of lupin stubble are extracted with methanol: water and purified by partitioning between n-butanol and water, chromatography on Amberlite XAD-2 and by cation exchange chromatography. The analysis is performed on a reverse phase C18 column using a methanol:water gradient and UV detection. The limit of detection for this procedure is 0.5 mg phomopsin A per kg stubble. Improvements to the extraction and purification procedures were made and total analysis time was reduced to 2 days. The mean (± s.d.) recovery for the purification procedure was 64.3 ± 4.5% over a wide range of concentrations.