KROMOTROP 2R LİGANDI KULLANILARAK KARE DALGA VOLTAMETRİSİ ile SULARDA BOR TAYİNİ

Bu çalışmada, borun eser miktarlarının kare dalga voltametrisi (SWV) ile tayini için bir yöntem geliştirilmiştir. Bu metot asılı duran civa damlası elektroduna, borik asit–kromotrop 2R kompleksinin adsorbe olmasına dayanır. Adsorbe olmuş bor kompleksine ait indirgenme pikinin akımı, kare dalga voltametrisi kullanılarak ölçülmüştür. Kompleks oluşum süresi yaklaşık olarak 50 dakikadır. Ortamda olabilecek girişim etkilerini elimine etmek amacıyla ortama etilendiamintetraasetik asit (EDTA) ilave edilmiştir. Liganda ait pik potansiyeli bu voltametrik metot kullanılarak (Ag / AgCl / KCl (doy.) referans elektroduna karşı) gözlenmiş ve çeşitli parametrelerin (ligand ve destek elektrolit konsantrasyonları vb.) etkisi incelenmiştir. Daha sonra bu pik analitik amaçlı olarak değerlendirilmiştir. Geliştirilen metodun çalışma aralığı kaynak sularında eser miktarda bor tayini için 1,0 × 10-8 M - 1,0 × 10-5 M olarak belirlenmiştir.

Anahtar Kelimeler:

Bor, Asılı duran Civa Damlası Elektrodu, Kare Dalga Voltametrisi, Kromotrop 2R

DETERMINATION of BORON in WATER with CHROMOTROPE 2R by SQUARE WAVE VOLTAMMETRY

In this paper an alternative method investigated to determine boron using boric acid-Chromotrpe 2R complex in water by Square Wave Voltammetry. Chromotrope 2R was used as the ligand for boron; the optimum conditions of the method were found to be: 1.0 M AcOH / 0.5 M NH4OAc buffer as supporting electrode; 1.0 × 10-4 M Chromotrope 2R as standard solution; solution pH is at about 4.4 ± 0.2, and 100 mV/s sweep rate. The linear range of the determination of trace boron in natural water is 1.0 × 10-8 M - 1.0 × 10-5 M. The complex formation is completed approximately 50 minutes. The possible interferences could be eliminated by adding EDTA to the solution media. The method was applied to the determination of boron as boric acid in natural water samples.

Keywords:

Boron, Hanging Mercury Dropped Electrode, Square Wave Voltammetry, Chromotrope 2R,

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[1] W. Jin, K. Jiao, H. Metzner. On the adsorption voltammetry of the Boron-Beryllon III system: Part II. Mechanism of the electrochemical reduction of Beryllon III and its complex with B(III) in acetate buffer. Electroanalysis 5 (1993), 445 - 453.
[2] W. Jin, K. Jiao, H. Metzner. On the adsorption voltammetry of the Boron- Beryllon(III)* system: Part I. Determination of boron in plants and soils. Electroanalysis 5 (1993), 437 - 443.
[3] W. Jin, L. Xiao, Y. Wan. Investigations on adsorption potentiometry: Part IX. Determination of ultratrace boron by derivative adsorption chronopotentiometry. Anal. Chim. Acta 280 (1993), 69 - 74.
[4] S. Motomizu, M. Oshima, Z. Jun. Anal. Chim. Acta, 251 (1991), 269 - 274.
[5] H.F. Mark, Jr. J.J. McKetta, D.F. Othmer. Encyclopedia of Chemical Technology, 2nd ed. ; J. Wiley & Sons Inc. ; New York, ; Vol. 3, (1968), pp. 602 - 737, and Vol., pp. 86-87.
[6] G.S. Spicer and J.D.H. Strickland. The determination of microgram and submicrogram amounts of boron absorptiometric determination using curcumin. Anal. Chim. Acta 18 (1958), 231 - 239.
[7] R. Kunin and A.F. Preuss. Characterization of boron-specific ion exchange resin. I & EC Prod. Res. Dev. 3 (1964), 304 - 306.
[8] Sah R.N. and P.H. Brown. Boron determination-A review of analytical methods. Microchem. J. 56 (1997) 285-304.
[9] Doménech-Carbó A., S. Sánchez-Ramos, D.J. Yusá-Marco, M. Moya-Moreno, J.V. Gimeno-Adelantado, F. Bosch-Reig. Electrochemical determination of boron in minerals and ceramic materials. Anal. Chim. Acta 501 (2004) 103-111.
[10] Achterberg E.P. and C. Braungardt. Stripping voltammetry for the determination of trace metal speciation and in-situ measurements of trace metal distributions in marine waters. Anal. Chim. Acta 400 (1999) 381- 397.
[11] Thunus L. Voltammetric determination of boron in plasma using Beryllon(III) as a ligand. Anal. Chim. Acta 318 (1996), 303 - 308.
[12] ISO 8466–1, Water quality–Calibration and evalution of analytical methods and estimation of performans characteristics, Part 1: Statistical evalution of the lineer calibration function. 1990.
[13] ISO/DIS 8466–1. Water quality–Calibration and evalution of analytical methods and estimation of performans characteristics, Part 3:Method of Standard Addition.1990.