US EPA

3228020 

Journal Article 

Polyaniline/graphene quantum dot-modified screen-printed carbon electrode for the rapid determination of Cr(VI) using stopped-flow analysis coupled with voltammetric technique 

Punrat, E; Maksuk, C; Chuanuwatanakul, S; Wonsawat, W; Chailapakul, O 

2016 

1 

Talanta
ISSN: 0039-9140
EISSN: 1873-3573 

150 

198-205 

English 

26838400 

10.1016/j.talanta.2015.12.016 

WOS:000370770500027 

http://://WOS:000370770500027
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Polyaniline/graphene quantum dots (PANI/GQDs) were used to modify a screen-printed carbon electrode (SPCE) in a flow-based system. A method for rapidly determining the Cr(VI) concentrations by using stopped-flow analysis has been developed using an Auto-Pret system coupled with linear-sweep voltammetry using the PANI/GQD-modified SPCE. The GQDs, synthesized in a botton-up manner from citric acid, were mixed with aniline monomer in an optimized ratio. The mixture was injected into an electrochemical flow cell in which electro-polymerization of the aniline monomer occurred. Under conditions optimized for determining Cr(VI), wide linearity was obtained in the range of 0.1-10 mg L(-1), with a detection limit of 0.097 mg L(-1). For a sample volume of 0.5 m L, the modified SPCE can be used continuously with a sample-throughput of more than 90 samples per hour. In addition, this proposed method was successfully applied to mineral water samples with acceptable accuracy, and the quantitative agreement was accomplished in deteriorated Cr-plating solutions with a standard traditional method for Cr(VI) detection. 

article; Chromium(VI); Polyaniline; Graphene quantum dot; Stopped-flow analysis; Voltammetry; aniline; carbon electrodes; chromium; citric acid; detection limit; electrochemistry; graphene; mineral water; quantum dots