Novel samarium(III) selective membrane sensor based on glipizid

We found that N-[2-[4-[[[(cyclohexyl amino)carbonyl]amino]sulfonyl]phenyl]ethyl]-5-methyl pyrazine carboxamide (glipizid) can be used as an excellent ionophore to make a novel samarium-selective membrane sensor. The electrode based on glipizid, containing sodium teraphenyl borate as lipophilic salt and benzyl acetate as a plasticiser, gave the best performance. The electrode exhibits a good Nernstian response towards Sm3+ions in the range of 1.0×10−1 to 1.0×10−6 M with a slope of 19.8 mV per decade. It shows a high selectivity for Sm(III) in comparison with alkali, alkaline earth, heavy metal and transition metal ions. The electrode response and selectivity remained almost unchanged for at least 2 months. The electrode was successfully applied as an indicator electrode in potentiometric titration of Sm(III) ions with EDTA.