Selective Detection of Magnesium ions(II) using a new modified carbon paste Electrode

Abstract

In this work, we adopt preparation a new carbon paste electrode for Magnesium ions based on a (7% complex: EDTA (2,2',2'',2'''-(ethane-1,2-diyldinitrilo)tetraacetic acid ) as electroactive material ( 45.5% Plasticizers (Paraffin Oil), 45.5% Graphite Powder,2% MgO) , This electrode revealed a good selectivity for ions in a wide linear dynamic range  of ( 1.0 ˣ 10^-5 – 1.0 ˣ 10^-2 ) M . The electrode exhibit a Nernstain response of (27.85) mv per decade of Magnesium ions , the detection limit was ( 1ˣ 10 ^–5 ) M . The response time was about (25-30) s and the electrode can be used for 3 months at least. The applicable pH range was obtained (5 –9). By using Matched Potential Methods ( MPM ),The Proposed electrode show a very good selectivity towards Mg²⁺ ion in presence of some Transition , heavy metal ions with the correlation coefficient ( 0.996) ,SD : 6.83×10⁻⁵ , RSD : 3.99%, It was found that there were no significant differences between the two methods and the method used is characterized by accuracy and precision.