Fig. 4

Individual factor effects from Box-Behnken design on fluorescence quenching ratio (F0/F). (A) Effect of pH showing parabolic relationship with optimum at pH 6.4. (B) Effect of Erythrosin B concentration with optimum at 13.0 µg/mL. (C) Effect of buffer volume with optimum at 1.1 mL. (D) Effect of incubation time showing minimal influence across the studied range.