- Turkish Journal of Chemistry
- Vol: 27 Issue: 4
- Voltammetric and Flow Injection Amperometric Determination of Cysteine at a Glassy Carbon Electrode ...
Voltammetric and Flow Injection Amperometric Determination of Cysteine at a Glassy Carbon Electrode in the Presence of Copper(II) Ions
Authors : Zekerya Dursun, Ilyas Şahbaz, F. Nil Ertaş, Gürel Nişli
Pages : 513-520
View : 8 | Download : 4
Publication Date : 9999-12-31
Article Type : Makaleler
Abstract :The voltammetric behaviour of cysteine was investigated in the presence of Cu(II) ions at a rotating glassy carbon electrode (RGCE). Two reduction peaks related to the successive reduction of the cysteine complexes of Cu(II) and Cu(I) ions were observed at --0.30 and --0.60 V vs. SCE respectively. These peaks were increased upon the addition of cysteine into a pH 9.20 borate buffer solution containing 0.1 M KNO3 and 1.0 x 10-5 M Cu(II) ions. The calibration curve was linear in the concentration range of 5.0 x 10-10- 2.0 x 10-8 M for cysteine by utilising the peak current at --0.6 V vs. SCE. In the flow technique, 50 m L portions of off-line prepared mixtures of 1.0 x 10-5 M Cu(II) and varying concentrations of cysteine were injected into the carrier solution of pH 9.20 borate buffer containing 0.1 M KNO3 flowing through 25 cm transmission tubing (i.d. 0.75 mm) at a rate of 1.5 mL/min. The signals were monitored at -- 0.60 V vs. SCE. The calibration graph was found to be linear in the concentration range 1.0 x 10-9 -- 1.0 x 10-7 M with a relative standard deviation of 1.0% (n = 5) for 5.0 x 10-8 M cysteine. The detection limit was calculated as 5 x 10-10 M for S/N = 3 ratio.Keywords : Turk. J. Chem., 27, (2003), 513-520. Full text: pdf Other articles published in the same issue: Turk. J. Chem., vol.27, iss.4.