Detection and determination of mycotoxins by LC-MS-MS, e.g. comparative levels of fumonisins B₁ and B₂ within isogenic non-Bt (A, B) and Bt maize (C, D) harvested samples. For fumonisin B₁, we observed 4 × 10⁶ cps value in isogenic non-Bt maize (Fig. 2, A) versus 6000 cps in Bt maize (Fig. 2, C). For fumonisin B₂, 6 × 10⁵ cps were noted in isogenic non-Bt maize (Fig. 2, B) versus 1240 cps recorded in Bt maize (Fig. 2, D).