Effects of surface-active substances in square-wave voltammetry and potentiometric stripping analysis of amalgam-forming metal ions

1994 ◽  
Vol 349 (8-9) ◽  
pp. 633-638 ◽  
Author(s):  
Sebojka Komorsky-Lovrić ◽  
Marko Branica
2003 ◽  
Vol 15 (18) ◽  
pp. 1465-1475 ◽  
Author(s):  
A. Doménech-Carbó ◽  
M. T. Doménech-Carbó ◽  
L. Osete-Cortina ◽  
J. V. Gimeno-Adelantado ◽  
S. Sánchez-Ramos ◽  
...  

Author(s):  
İsmail Murat Palabıyık ◽  
Aysegul Dogan ◽  
İncilay Süslü

Background: Hypertension is one of the most important health problems in the world and irbesartan and amlodipine are used in combination in various dosages for the treatment of high blood pressure. Objective: The aim of this study is to develop a fast, easy, sensitive, accurate, and precise square-wave voltammetry method for simultaneous determination of irbesartan and amlodipine besylate from pharmaceutical formulations at a hanging mercury drop electrode. Methods: In the applied method, since both active substances gave a peak at different potentials, no interference occurred between them. In optimization studies Britton-Robinson buffer of pH 8.0 was chosen, in which the most appropriate peak shape and maximum peak current were observed. At the same time, as a result of instrumental parameter optimization to obtain reproducible results, 6 mV for scan increment, 30 mV for pulse amplitude, and 50 Hz for frequency were found suitable. Results: As a result of the calibration studies of the optimized method, linear working ranges were determined as 1.00-13.08 µg mL-1 for irbesartan and 5.83-16.51 µg mL-1 for amlodipine besylate. Limit of detection and limit of quantitation values were respectively calculated as 0.63 and 1.00 µg mL-1 for irbesartan and 0.50 and 1.98 µg mL-1 for amlodipine besylate. The results of precision values (RSD) ranged from 0.67% to 2.31% for irbesartan and 0.65% to 1.49% for amlodipine besylate. Accuracy values were calculated as -0.15% to 1.63% for irbesartan and -0.07% to 3.78% for amlodipine besylate. The results obtained from the recovery studies ranged from 101.05% to 102.78% and from 98.88% to 102.20% for amlodipine besylate and irbesartan, respectively. Conclusion: After the validation studies of the developed method were carried out, it was successfully applied to pharmaceutical formulations containing these active substances.


2019 ◽  
Vol 17 (1) ◽  
pp. 722-727 ◽  
Author(s):  
Veton Haziri ◽  
Avni Berisha ◽  
Fetah I. Podvorica

AbstractThe electrochemical grafting of the “in-situ” prepared diazopyridinium salt have permitted the attachment of pyridine moieties onto platinum and glassy carbon surfaces. The modification of the electrode surfaces is observed by a redox probe. The ability of the film for the complexation of copper (II) ions is demonstrated by square wave voltammetry. After 45 min accumulation of copper (II) ions onto the grafted electrode surfaces, the electrode signal obtained by square wave voltammetry measurement served to discriminate the adsorbed heavy metal ions. Such measurements showed that the grafted pyridine has the ability to display complexing behavior toward some heavy metal ions. DFT calculations support a strong binding of the pyridine moieties onto the Pt surface. The most favorable complexation mode of copper (II) ions as suggested from DFT is the bidentate complex. This strategy is vital in constructing a wide range of different electrochemical sensors.


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