Room temperature phosphorescence quenching study of coumarins. Indirect determination of warfarin in pharmaceuticals

Abstract

Room temperature phosphorescence of the 1-bromonaphthalene/b-cyclodextrin/cyclohexane inclusioncomplex was studied in the presence of coumarins: warfarin, coumarin, dicumarol and umbelliferone.The differences encountered when using right-angle or front-face illumination geometry are shown inorder to mark the importance of a correct measurement. Phosphorescence static quenching wasobserved with the coumarins, as the phosphorescence lifetimes could reveal. Warfarin determinationwas performed using a commercial anticoagulant making use of the interaction between coumarins andthe studied inclusion complex