Ion-selective membrane sensors for the determination of tinidazole and clarithromycin in bulk powder and pharmaceutical formulation

The construction and electrochemical response characteristics of three selective electrodes were investigated using precipitation based technique with phosphotungstate and phosphomolybdate; respectively upon using polyvinyl chloride (pvc) matrix and dioctyl phthalate (dop) as a plasticizer. the resultant membrane sensors were tinidazole phosphotungestate (tnd-pta) electrode (sensors 1), tinidazole phosphomolybdate (tndpma) electrode (sensors 2) and clarithromycin phosphotungestate (clr-pta) electrode (sensors 3). linear responses of tnd and clr within the concentration ranges of 10−6to 10−2mol/l for sensors 1, 2 and 3 were observed. nernstian slopes of 58.3, 57.1 and 58.8 mv/decade were observed over the ph range of 3-7 for sensors 1and 2 and over range of 3-8 for sensor 3, respectively. the selectivity coefficients of the developed sensors indicated excellent selectivity for tnd and clr. the proposed sensors displayed useful analytical characteristics for the determination of tnd and clr in bulk powder and pharmaceutical formulation (helicure® tablets).