Popis: |
The effects of aqueous micellar systems on the derivatization of a fatty acid, 10-undecenoic acid (UA), with a flourophore, 4-bromomethyl-7-methoxycoumarin (BrMMC), were examined. High derivatization rates were obtained in solutions of the non-ionic surfactants Triton-X 100 and Arkopal N in the presence of cationic ion-pair reagents such as tetrahexylammonium bromide. The derivatization mechanism is probably based on phase-transfer catalysis. Especially high reaction rates are obtained in turbid non-ionic micellar solutions. This opaqueness is connected with an important optimizing parameter of the derivatization rate, the so-called cloud temperature of a micellar system. Under the optimal conditions the derivatizaton of UA with BrMMC is complete within 45 min at 70°C. |