scholarly journals Determination of Total Germanium in Chinese Herbal Remedies by Square-Wave Catalytic Adsorptive Cathodic Stripping Voltammetry at an Improved Bismuth Film Electrode

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Shangwei Zhong ◽  
Jiali Su ◽  
Liang Chen ◽  
Jiefeng Tong ◽  
Wenfang Jia ◽  
...  

A catalytic adsorptive cathodic stripping voltammetric method on an improved bismuth film electrode (BiFE) for the determination of trace germanium in the presence of pyrogallol has been investigated. A well-defined and sensitive stripping peak of Ge(IV)-pyrogallol complex was observed at −0.79 V (versus SCE) in a 0.1 M acetate buffer solution (pH 4.8) at a deposition potential of −0.34 V. The reduction current is catalytically enhanced by adding KBrO3. The experimental variables and potential interference were studied. Compared with the BiFE plated in the solution prepared based on HAc-NaAc without trisodium citrate, the improved BiFE electrodeposited in the solution of HAc-NaAc containing trisodium citrate displayed a better electroanalytical performance for the determination of germanium(IV). Under the optimized conditions, the detection limit of Ge(IV) was 60 ng L−1, and the relative standard deviation (RSD) was 3.73% at 5 μg L−1level (n=9). This method was successfully applied to determine the total germanium in several Chinese herbal remedies.

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Karen C. Bedin ◽  
Edson Y. Mitsuyasu ◽  
Amanda Ronix ◽  
André L. Cazetta ◽  
Osvaldo Pezoti ◽  
...  

The present work reports the development and application of bismuth-film electrode (BiFE), obtained by in situ method on the pencil-lead graphite surface, for simultaneous Cd(II) and Pb(II) determination at trace levels, as alternative to replace the mercury-film electrodes. Experimental factors, deposition time (td), deposition potential (Ed), and Bi(III) concentration (CBi), were investigated by applying a 23 factorial design using 0.10 mol/L acetate buffer solution (pH 4.5) as supporting electrolyte. The analysis conditions of the differential pulse technique were td = 250 s, Ed = -1.40 V, and CBi = 250 mg L−1. The validation of the method employing BiFE was accomplished by determination of merit figures. The detection limits were of 11.0 μg L−1 for Cd(II) and 11.5 μg L−1 for Pb(II), confirming that proposed method is attractive and suitable for heavy metals determination. Additionally, the BiFE developed was successfully applied for the Cd(II) and Pb(II) determination in wastewater sample of battery industry.


Author(s):  
Hao Zhang ◽  
Jun Cui ◽  
Yuxin Zeng ◽  
Yu Zhang ◽  
Yuansheng Pei

Abstract A sensitive, selective, and stable sensor for the simultaneous determination of Cd2+ and Pb2+ in aqueous solution has been developed based on the carbon dots (CDs) and Nafion-modified bismuth film glassy carbon electrode (GCE). High graphitized CDs prepared by the sulfuric acid-assisted hydrothermal synthesis were directly electrodeposited on the GCE surface by cyclic voltammetry. Compared with the conventional bismuth film electrodes, CDs greatly improved the electrochemical activity of the bismuth film electrode for the detection of Cd2+ and Pb2+. After decorating CDs, the surface impedance of the GCE was decreased from 10.9 kΩ to 4.84 kΩ. Meanwhile, the corresponding response currents of the Bi/GCE were increased over 7.4 and 2.4 times for Cd2+ and Pb2+ with a wide linear range of 0.05-0.50 mg/L, respectively. High sensitivity was obtained with the detection limits of 3.1 μg L-1 (Cd2+) and 2.3 μg L-1 (Pb2+). Moreover, good stability was obtained for the simultaneous determination of Cd2+ and Pb2+ in the practical underground water with the relative standard deviations less than 10%. The results indicated that the CDs-modified bismuth film electrode could potentially be applied to detect the heavy metal ion concentrations in practical environment.


Talanta ◽  
2004 ◽  
Vol 63 (4) ◽  
pp. 849-855 ◽  
Author(s):  
Emily A. Hutton ◽  
Johannes T. van Elteren ◽  
Božidar Ogorevc ◽  
Malcolm R. Smyth

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