Determination of Mn۲+ in Pharmaceutical Supplements by a Novel Coated Graphite Electrode Based on Zolpidem as a Neutral Ion Carrier

Manganese plays a key role in the health of human beings therefore, its determination is very important in medical fields. In this regards, a novel coated graphite electrode was constructed for determination of manganese (II) by using zolpidem as an ionophore, for the first time. The best performance was obtained of the membrane composition of PVC (۳۲%), Potassium tetrakis (۴-chlorophenyl) borate (۳%) as ionic additive, zolpidem (۱۰%) as ionophore and Dioctyl phthalate (۵۵%) as Plasticizer. The linear working range of the potentiometric sensor was from ۱×۱۰-۷ to ۱×۱۰-۲ Mol L-۱. The electrode shows an exquisite Nernstian slope value of ۲۹.۷ mV.Decade-۱ and its limit of detection was ۹×۱۰-۸ Mol L-۱. The potential response of the membrane sensor was also evaluated in non aqueous mediums and it was found out that the electrode can also be used in systems that are entailed of ۱۵% of ethanol and acetone organic solvents. The selectivity subject was also inspected by matched potential method over ۲۰ different cations and the electrode demonstrates an eminent selectivity toward Mn۲+ over all of the studied cations. In the end, the applicability of the electrode in the determination of Mn۲+ in dietary supplements as real samples was investigated.

Keywords:

manganese , Zolpidem , Ion selective electrode , Potentiometry , Quality control of supplements