*2.6. VICAM Aflatoxins Assay*

Culture broth filtrates of 21 aflatoxigenic *Aspergilii* collected from peanut cake and cotton seeds were analyzed for aflatoxins production (B1, B2, G1, and G2) (Figure 1) using AflaTest Immunoaffinity (VICAM) Chromatography assay that quantifies total aflatoxin concentrations according to the manufacturer's instructions. Briefly, 5 mL of diluted sample extract (2:3, extract:water) was filtered through the column with immunological properties with a drop per second. The column was cleaned with 10 mL of water by running two drops per second through the column. Aflatoxin was eluted by transferring 1 mL of methanol at one drop per second from the column. A volume of 1 mL of bromine developer was added to the methanol elute and the total aflatoxin concentration was read in a pre-calibrated VICAM Series-4 Fluorometer set at 360 nm absorption and 450 nm emissions with a detection limit of 2 ppb (2µg/kg). Results for each sample were averaged and reported in ppb [28].

**Figure 1.** Structural formula of two type of aflatoxins produced by *A. flavus* isolated from peanut meal and cotton seed. Aflatoxin (B1) C17H12O<sup>6</sup> (6aR,9aS)-4-Methoxy-2,3,6a,9a-tetrahydrocyclopenta[c] furo[3′ ,2′ :4,5]furo[2,3-h]chromen-1,11-dion. Aflatoxin (B2), C17H14O<sup>6</sup> (6aS,9aR)-4-Methoxy-2,3,6a,8,9,9a hexahydrocyclopenta[c]furo[3′ ,2′ :4,5]furo[2,3-h]chromen-1,11-dion. Formula available online from: http://www.chemspider.com.
