M. Shamsipur et al., Strontium-selective membrane electrodes based on some recently synthesizedbenzo-substituted macrocyclic diamides, ANALYT CHEM, 71(21), 1999, pp. 4938-4943
Eight different recently synthesized macrocyclic diamides were studied to c
haracterize their abilities as strontium ion carriers in PVC membrane elect
rodes. The electrode based on 1,13-diaza-2,3;11,12-dibenzo-4,7,10-trioriacy
clopentadecane-14,15-dione exhibits a Nernstian response for Sr2+ ions over
a wide concentration range (1.0 x 10(-1)-3.2 x 10(-5) M) with a limit of d
etection of 8.0 x 10(-6) M (0.7 ppm). The response time of the sensor is si
milar to 10 s, and the membrane can be used for more than three months with
out observing any deviation. The electrode revealed comparatively good sele
ctivities with respect to many alkali, alkaline earth, and transition metal
ions. It was used as an indicator electrode in potentiometric titration of
carbonate ions with a strontium ion solution.