Lead(II)-Selective Membrane Electrodes Based on 4,7,13,16-Tetrathenoyl-1,10-dioxa-4,7,13,16-tetraazacyclooctadecane
✍ Scribed by Xinhao Yang; Naresh Kumar; D. Brynn Hibbert; Peter W. Alexander
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 97 KB
- Volume
- 10
- Category
- Article
- ISSN
- 1040-0397
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✦ Synopsis
Lead(II)-selective PVC membrane electrodes based on 4,7,13,7,13, as ionophore were prepared. The optimum composition of the membrane was 30 wt% poly(vinyl chloride), 67 wt% 2-nitrophenyl octyl ether plasticizer, 3 wt% ionophore with added lipophilic salt potassium tetrakis( p-chlorophenyl)borate at 50 mol% with respect to the ionophore concentration. The electrodes exhibited near theoretical Nernstian slopes (31.9 Ϯ 0.4 mV/per decade) in the activity range log 10 [a(Pb 2þ )] = ¹5.3 to log 10 [a(Pb 2þ )] = ¹3.0 and with a detection limit log 10 [a(Pb 2þ )] = ¹5.7. Compared to the previously reported disubstituted, diazacrown 7,16dithenoyl-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane the electrodes based on TTOTC showed much better selectivity particularly towards alkali and alkaline metal ions. However, mercury and silver remain the major interferences. The electrodes were used in potentiometric titrations of Pb 2þ and the determination of Pb 2þ in synthetic soil samples.