TY - JOUR
T1 - Multiequilibria of 2-(2’-furanyl)-1H-Benzimidazole Neutral and Protonated Forms in the Presence of Amphiphilic Aggregates
AU - Lopes, António
AU - Andrade Maçanita, António Luís Vieira
AU - Pina, Fernando Jorge da Silva
AU - Melo, E.
AU - Wamhoff, Heinrich
PY - 1992
Y1 - 1992
N2 - The solubility of 2-(2’-furanyl)-lH-benzimidazole (Fuberidazole) in water-surfactant systems is measured as a function of the pH. The partition constants between water and the micellar pseudophase of both neutral and protonated forms of Fuberidazole (pKal = 5.0) are determined in buffered solutions of an anionic surfactant, sodium dodecyl sulfate (SDS), a cationic surfactant, hexadecyltrimethylammonium chloride (HTAC), and a nonionic surfactant, polyoxyethylene( 10) lauryl ether (C12E10) using the fluorescence anisotropy method, and the results compared with those obtained for the octanol-water system. Both forms of Fuberidazole are shown to dissolve readily in the polyoxyethylene region of the ClzElo micelles, with partition constants of 190 f 20 and 3.8 f 0.2 at 25 “C for the neutral and protonated forms, respectively. In SDS, much higher values of the partition constants are observed, respectively, 310 f 25 and 11 600 f 1O00, presenting a very low temperature dependence. As expected, the cation is not soluble in HTAC micelles, but the neutral form presents a high partition constant of 850 f 80. Finally, we discuss the partition of Fuberidazole and protonated Fuberidazole between micelle and water as a function of the volume fraction of lipidic media, for different pH values.
AB - The solubility of 2-(2’-furanyl)-lH-benzimidazole (Fuberidazole) in water-surfactant systems is measured as a function of the pH. The partition constants between water and the micellar pseudophase of both neutral and protonated forms of Fuberidazole (pKal = 5.0) are determined in buffered solutions of an anionic surfactant, sodium dodecyl sulfate (SDS), a cationic surfactant, hexadecyltrimethylammonium chloride (HTAC), and a nonionic surfactant, polyoxyethylene( 10) lauryl ether (C12E10) using the fluorescence anisotropy method, and the results compared with those obtained for the octanol-water system. Both forms of Fuberidazole are shown to dissolve readily in the polyoxyethylene region of the ClzElo micelles, with partition constants of 190 f 20 and 3.8 f 0.2 at 25 “C for the neutral and protonated forms, respectively. In SDS, much higher values of the partition constants are observed, respectively, 310 f 25 and 11 600 f 1O00, presenting a very low temperature dependence. As expected, the cation is not soluble in HTAC micelles, but the neutral form presents a high partition constant of 850 f 80. Finally, we discuss the partition of Fuberidazole and protonated Fuberidazole between micelle and water as a function of the volume fraction of lipidic media, for different pH values.
UR - http://www.scopus.com/inward/record.url?scp=0027070763&partnerID=8YFLogxK
U2 - 10.1021/es00036a017
DO - 10.1021/es00036a017
M3 - Article
SN - 0013-936X
VL - 26
SP - 2448
EP - 2453
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 12
ER -