Determination of cyclodextrin content using periodate oxidation by capillary electrophoresis

A simple and general method suitable for the determination of cyclodextrin content in various matrices is described. The proposed method involves sele ctive cleavage of C-C bonds with vicinal hydroxyl groups by means of period ate (Malaprade's reaction). The amount of produced iodate is monitored by c apillary electrophoresis, Optimized electrophoretic conditions (20 mM disod ium tetraborate with 1 mM tetradecyltrimethylammonium bromide, direct UV de tection lambda=200 nm) ensure complete separation of periodate and iodate i ons and sufficient sensitivity towards iodate. Under optimized reaction con ditions (2-fold excess of periodate, temperature 70 degrees C) reproducible quantitative results were obtained for alpha-, beta- and gamma-cyclodextri ns as model samples. The proposed method was tested on a real sample of acr ylamide - 2'-O-allyl-beta-CD copolymer. The values of beta-cyclodextrin con tent were compared with those obtained by reference NMR measurement and wer e found to be identical. (C) 2000 Elsevier Science B.V. All rights reserved .