26 April 2011
. DOI 10.1007/978-3-642-19038-4_6.
Verónica Sánchez-Paza, María José Pastoriza-Gallegoa, Carlos Bravo-Díaz*a, Laurence S. Romstedb
Autor affilations:
*Corresponding authors
aDpt. Química Física, Facultad de Química, Universidad de Vigo, Vigo-Pontevedra, Spain
bDepartment of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
E-mail: cbravo@uvigo.es
Abstract
We have determined the distribution of the antioxidant tert-butylhydroquinone, TBHQ, between the oil and interfacial regions of an emulsion composed of stripped corn oil, acidic water and hexaethyleneglycol monododecyl ether, C12E6, 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 [C12E6].
