A 200 g sub-sample was drawn from each 500 (or 400) g sample
and divided into two equal portions. The powder (or peanut paste)
was triturated in a blender in 70% methanol (70 ml absolute
methanol in 30 ml distilled water, v/v) containing 0.5% potassium
chloride (w/v) until thoroughly mixed. The extract was transferred
to a conical flask and shaken for 30 min at 300 rpm. The extract was
then filtered through Whatman No. 41 filter paper and diluted 1:10
in phosphate buffered saline containing 500 ml/l Tween-20 (PBSTween)
and analyzed for aflatoxin contamination using Indirect
Competitive Enzyme-Linked Immunosorbent Assay (ELISA) as
described by Waliyar et al. (2005)