Simultaneous determination of trace Sn(II) and Sn(IV) using differential pulse polarography and application

Authors : Ülkü ÜNAL and Güler SOMER

Pages : 73-85

Doi:10.3906/sag-1207-72

View : 17 | Download : 11

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :A new method was established for the simultaneous determination of Sninsert ignore into journalissuearticles values(II); and Sninsert ignore into journalissuearticles values(IV); using differential pulse polarography insert ignore into journalissuearticles values(DPP);. Among several electrolytes, 0.1 M NaOH in the presence of 0.1 M KNO3 was found to be the most suitable one. In this medium, Sninsert ignore into journalissuearticles values(II); had 2 peaks, at -0.74 and -1.17 V, which were sharp and very sensitive. Sninsert ignore into journalissuearticles values(IV);, on the other hand, had a very small peak at -0.92 V when its concentration was higher than 4.0 \times 10-4 M. Thus, it was decided to determine Sninsert ignore into journalissuearticles values(IV); after reduction into Sninsert ignore into journalissuearticles values(II);. In the presence of both Sninsert ignore into journalissuearticles values(II); and Sninsert ignore into journalissuearticles values(IV);, Sninsert ignore into journalissuearticles values(II); was first determined from the peak at -1.17 V, and then Sninsert ignore into journalissuearticles values(IV); was determined after its reduction with NaBH4 into Sninsert ignore into journalissuearticles values(II);. The detection limit was 5.5 \times 10-7 M and 8.2 \times 10-7 M for Sninsert ignore into journalissuearticles values(II); and Sninsert ignore into journalissuearticles values(IV);, respectively. The interference effect of the most common ions, Feinsert ignore into journalissuearticles values(III);, Cuinsert ignore into journalissuearticles values(II);, Pbinsert ignore into journalissuearticles values(II);, Cdinsert ignore into journalissuearticles values(II);, and Zninsert ignore into journalissuearticles values(II);, was investigated. Only copper and iron had an interfering effect during the speciation procedures, since they oxidized Sninsert ignore into journalissuearticles values(II);, which was formed after reduction of Sninsert ignore into journalissuearticles values(IV); for its determination. This effect of Cuinsert ignore into journalissuearticles values(II); and Feinsert ignore into journalissuearticles values(III); ions could be eliminated by the reducing agent NaBH4, which was used for the reduction of Sninsert ignore into journalissuearticles values(IV);. Since Pbinsert ignore into journalissuearticles values(II); and Cdinsert ignore into journalissuearticles values(II); peaks overlap with the first peak of Sninsert ignore into journalissuearticles values(II); at -0.74V, Sninsert ignore into journalissuearticles values(II); was determined using the second peak, at -1.17 V. In a synthetic sample containing Sninsert ignore into journalissuearticles values(II);, Sninsert ignore into journalissuearticles values(IV);, and all common ions, the total content of tin insert ignore into journalissuearticles values(2.0 \times 10-5 M); was found to be insert ignore into journalissuearticles values(2.07 \pm 0.38); \times 10-5 M insert ignore into journalissuearticles values(90% CI, N = 3);. This method was applied for the determination of tin in canned tomato sauce.
Keywords : Speciation, tin, differential pulse polarography, interference elimination, canned tomato sauce