Nano-molar level detection of calcium folinate and methotrexate using a cationic surfactant and multivariate optimization: A simple tool for simultaneous and sensitive analysis

Abstract

This study is the first report for simultaneous determination of calcium folinate (CF) and methotrexate (MTX) in nano-molar level using a simple modified carbon paste electrode (CPE) by cationic surfactants. N-dodecylpyridinium chloride (DPC) as a cationic surfactant has not yet been used successfully as a mod-ifier in any simultaneous electrochemical measurements. Initially, the performance of DPC for modifica-tion of the electrode surface is compared with a well-known cationic surfactant. Then, after revealing the superiority of DPC, it is used as a modifier. Under the optimum conditions, using multivariate optimiza-tion, the oxidation peak current of CF in the presence of 10.0mM MTX is linear in the concentration range of 0.1–10.0mM with a detection limit of 17.5 nM. Under similar conditions, the oxidation peak current of MTX in the presence of 10.0mM CF is linear in the concentration range of 0.05–10.0mM with a detection limit of 9.3 nM.