Distribution of Tert-Butylhydroquinone in a Corn Oil/C_(12)E_6/Water Based Emulsion. Application of the Pseudophase Kinetic Model

摘要

We have determined the distribution of the anti-oxidant tert-butylhydroquinone, TBHQ, between the oil and interfacial regions of an emulsion composed of stripped corn oil, acidic water and hexaethyleneglycol monododecyl ether, C_(12)E_6, by employing a kinetic method based on the reaction between the hydrophobic 16-hexadecylbenzenediazonium ions, 16-ArN2+, and TBHQ. The kinetic data are interpreted under the light of the pseudophase kinetic model and provide estimates of the partition constant, and hence the distribution, of TBHQ between the oil and the interfacial region of the emulsion. Our results show that more than 80% of TBHQ is located in the interfacial region even at low emulsifier volume fractions, and the fraction of TBHQ in that region increases upon increasing [C_(12)E_6].