Sensitive Adsorptive Stripping Voltammetric Determination of Xanthine and its Derivatives

Raqi Shubietah's picture
Journal Title, Volume, Page: 
Electroanalysis Electroanalysis Volume 7, Issue 10, pages 975–979, October 1995
Year of Publication: 
1995
Authors: 
Raqi M. Shubietah
Department of Pharmacy, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine
Current Affiliation: 
Department of Pharmacy, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine
Ali Z. Abu Zuhri
Chemistry Department, An- Najah National University, Nablus, Palestine
Arnold G. Fogg
Chemistry Department, Loughborough University of Technology, Loughborough, Leicestershire LE11 3TU, UK
Preferred Abstract (Original): 

Sensitive cathodic stripping voltammetric procedures for trace determination of xanthine (I), 7-methylxanthine (II) and 1,7-dimethylxanthine (III) are reported. The methods are based on the accumulation of the copper(I) complexes of the compounds on the hanging mercury drop electrode. The adsorptive stripping response was evaluated with respect to accumulation time, potential, concentration, pH and other variables. Linear calibration graphs were obtained over the range from 2.0 × 10−8 to 2.0 × 10−9 M; the limits of detection, with accumulation times of 4 min for I and III, and of 6 min for II, were calculated to be 5.0 × l0−10 1.0 × 10−9 and 5 × 10−10 M, respectively. Possible interferences by other purine derivatives were examined. The simultaneous determination of 1.7-dimethylxanthine (paraxanthine) and theophylline is possible by the proposed method.