Electroanalytical performance of Cd(Ⅱ) selective sensor based on PVC membranes of 5,5'-(5,5'-(benzo[c][l,2,51thiadiazole-4,7-diyl)bis(thiophene-5,2-diyl))bis(N1,N1,N3,N3-tetr aphenylbenzene-1, 3-diamine)

摘要

The construction and performance characteristics of polymeric membrane electrodes based on neutral ionophore 5,5'-(5,5'-(benzo[c][1,2,5]thiadiazole-4, 7-diyl)bis(thiophene-5,2-diyl))bis-(N1,N1 ,N3,N3-tetraphenylbenzene-1,3-diamine) (L) for quantification of cadmium ions, are described. Effect of plastisizers dibutylpthalate (DBP), tri-n-butylphosphate (TBP), dioctylpthalate (DOP), o-nitrophenyloctyl ether (o-NPOE), 1-chloronaphthalene (CN) and ionic additives sodium tetraphenylborate (NaTPB), potassium tetrakis p-(chlorophenyl) borate (KTpClPB) was studied. Best performance was obtained with the membrane having a composition L:PVC: DBP: NaTPB ≡ 2: 37: 59:2 (w/w; mg). The membrane electrode exhibits Nernstian response in the concentration range 6.3 × 10~(-8) to 1.0×lO~(-1)molL~(-1) with detection limit 3.6 × 10~(-8)molL~(-1) and is not affected by H~+ ions over a wide pH range 3.0-10.0. The electrode possess a fast response time of 10s and shelf life period of 3 months. The analytical utility of the proposed electrode has demonstrated by its application in the determination of cadmium in water, medicinal plants and soil samples. It could also be used successfully as an indicator electrode in the potentiometric titration of Cd~(2+) with EDTA (ethylenediaminetetraacetic acid).