*2.5.2. Sample preparation and aflatoxin determination*

Aflatoxin analysis was carried out using immune-chromatographic assay Reveal Q+ mreader according to the manufacturer's recommendation. Prepared groundnut samples (500 g each) were ground finely using the Agri-Grind grinder until fine particles and homogeneity were obtained. Then, a subsample of 10 g was obtained from each of the composite samples. The subsample was aliquoting in 35 ml of 65% ethanol, and the contents were mixed gently by shaking the holding tube manually. After filtration of the blended subsample, 100 μl of the filtrate was mixed with 500 μl diluent solution in a dilution vial. After obtaining a fine mixture, a 100 μl extract of the aliquoted mixture was collected and added to a separate vial. Finally, a reveal Q+ test strip was placed in the vial containing the aliquoted mixture and was left to develop for 6 min. The test strip was later placed in the mreader holder, and the aflatoxin contamination levels of the sample were determined using the mreader based on the chromatographic characteristics of the sample in the strip. The data were statistically analyzed using GenStat Discovery 4. An independent Tukey's test was used to compare the means of the aflatoxin results. The tests for relationships were carried out using the Pearson Correlation Index, and the interpretation was performed at two-sided 95% confidence limit.
