Determination Trace Amounts of Magnesium (II) by a Potentiometric Sensor Based on Quetiapine as an Ionophore

In this research, a coated graphite electrode based on quetiapine as a neutral ion carrier was constructed for determination of Mg2+. The designed sensor demonstrates an ideal Nernstian slope (30.2 mV. Decade-1) over a wide concentration range (1×10-7- 1×10-2 M). The detection limit of the proposed sensor was 8×10-8 Mol L-1. The selectivity of the sensor was evaluated over 24 different cations by matched potential method and no serious interference was observed from them. The designed electrode could also be used in partially non aqueous mediums up to the presence of 20% of organic solvents without any tangible change in Nernstian slope and linearity domain. The response time and life span of the proposed electrode were 5s and 3 months respectively. The potential response of the sensor was independent from pH in the pH range of 3.0-8.0. At the end, the applicability of the designed sensor as an indicator electrode in potentiometric titration of Mg2+ with EDTA and determination of magnesium in some pharmaceutical products as real samples was also evaluated.