Enantioselective assay of S(+)-ibuprofen using enantioselective, potentiometric membrane electrodes based on maltodextrins

Three enantioselective, potentiometric membrane electrodes (EPMEs) based on maltodextrins with different values of dextrose equivalence(DE) (maltodextrin I: DE 4.0–7.0; maltodextrin II: DE 13.0–17.0; maltodextrin III: DE 16.5–19.5) were proposed for the assay of S-ibuprofen. The linear concentration ranges for the proposed EPMEs were 10−10 to 10−3, 10−8 to 10−3 and 10−10 to 10−3 mol l−1 for electrodes based on maltodextrin I, II and III, respectively. The slopes of the electrodes were 59.0, 58.4 and 55.6 mV/decade of concentration for maltodextrin I, II and III based EPMEs, respectively, with detection limits of 5.5 × 10−11, 8.0 × 10−9 and 4.1 × 10−12 mol l−1 for the electrodes based on maltodextrin I, II and III, respectively. A high reliability was obtained when the electrodes were used for the assay of S-ibuprofen raw material and its pharmaceutical formulations Myprodol capsules and Nurofen tablets. The surfaces of the electrodes are stable and easily renewable by polishing on alumina paper.