Desalination, Vol.271, No.1-3, 157-162, 2011
Potentiometric Cu2+-selective electrode with subnanomolar detection limit
A PVC membrane Cu2+ ion-selective electrode has been constructed using a new compound ethyl 1,2,3,4-tetrahydro-4-(4-methoxyphenyl)-6-methyl-2-oxopyrimidine-5-carbox ylate (ETMOC) as a neutral ionophore. The electrode works properly. It responds to Cu2+ ion with a sensitivity of 29.5 +/- 0.2 mV/decade over the range of 1.0 x 10(-9) to 5.0 x 10(-1) M at pH 3.0-8.0. The limit of detection was 4.5 x 10(-10) M. It has a response time of <6 s and can be used for at least 3 months without any divergence in potentials. The proposed electrode shows fairly good discrimination of Cu2+ ion from several cations. The effect of organic solvents on electrode response shows that this electrode can be used in methanol and ethanol media until 15% (v/v) concentration without interference. This sensor was used to determination of Cu2+ concentration in Tea leaves, Milk powder and Drinking water samples. (C) 2010 Elsevier B.V. All rights reserved.