*2.1.3 Method C (precipitation based on potassium ferrocyanide)*

This method is based on the detection of adulteration of milk with soy milk [9]. The protocols of method C were the same as method B, only except the precipitants of 3.0 mL 0.085 mol L<sup>−</sup><sup>1</sup> K4[Fe(CN)6] and 3.0 mL 0.25 mol L<sup>−</sup><sup>1</sup> ZnSO4 solutions employed in this method.
