Construction of Modified Screen-Printed and Carbon Paste Electrodes for Electrochemical Determination of Antihistaminic Diphenhydramine Hydrochloride in Pure and Pharmaceutical Preparations

摘要

The construction and performance characteristics of diphenhydramine hydrochloride (DPH) modifiedscreen printed (SPE) and carbon paste (CPE) electrodes with DPH-tetrapheylborate ion pair (DPH- TPB) (MSPE and MCPE) and with sodium tetraphenyl borate ion pairing agent (NaTPB) (in situ)(ISPE and ICPE) using tricrysylphosphate (TCP) as plasticizer are described. These electrodes exhibit-1 -6 -1 suitable response to DPH in the concentration range of 1x10 to 1x10 mol L with lower detection-7 -7 -7 -7 -1 limit of 9.65x10 , 9.68x10 , 9.78x10 and 9.76x10 mol L and response time of about 5, 6, 10 and-1 11s with Nernstian slope values of 56.200.65, 59.140.90, 55.861.12 and 60.031.32 mV decadefor MSPE, ISPE, MCPE and ICPE, respectively. The fabricated electrodes were used over a period of2 months under pH range of 2.5-8.0, 3.0-9.0, 2.5-7.0 and 3.0-8.0 for MSPE, ISPE, MCPE and ICPE,respectively. The analytical performance of the SPEs and CPEs compared with respect to selectivitycoefficients for DPH relative to a numbers of potential interfering substances were investigated. Themethod was applied for determination of DPH in pharmaceutical preparations with a percentagerecovery of 98.75-99.27, 98.95-99.66, 98.91-99.65 and 97.83-99.17% and and R.S.D = 0.54, 0.29, 0.26and 0.56 for MSPE, ISPE, MCPE and ICPE, respectively. The results are compared with the officialmethod.