TY - JOUR
T1 - Method development for the determination of mercury(II) by sequential injection/anodic stripping voltammetry using an in situ gold-film screen-printed carbon electrode
AU - Punrat, Eakkasit
AU - Chuanuwatanakul, Suchada
AU - Kaneta, Takashi
AU - Motomizu, Shoji
AU - Chailapakul, Orawon
N1 - Funding Information:
The authors are grateful for the financial support from Thailand Research Fund and Chulalongkorn University through the Royal Golden Jubilee Ph.D. Program ( PHD/0320/2551 ) to Eakkasit Punrat and Orawon Chailapakul; and the Thai Government Stimulus Package 2 ( TKK2555 ) under the Project for Establishment of Comprehensive Center for Innovative Food, Health Products and Agriculture (PERFECTA). The project has been carried out under the auspices of Chulalongkorn University and the CHE Centre of Excellence on Biodiversity (BDC) for the Second Century Beginning of Chulalongkorn University (2014–2017). We greatly appreciate Dr. Robert Butcher for his help in editing the manuscript under the service of the Publication Counseling Unit of the Faculty of Science, Chulalongkorn University.
PY - 2014/8/1
Y1 - 2014/8/1
N2 - A computer-controlled system, included a sequential injection system and an electrochemical detector, was developed for the determination of mercury(II) ion (Hg2+) concentrations. The screen-printed carbon electrode (SPCE), a well-known low-cost electrode, was modified by overlaying in situ with a gold film (Au-SPCE). Square wave anodic stripping voltammetry (SWASV) using the Au-SPCE was performed with a two-step deposition potential of an initial -0.5 V vs Ag/AgCl for the preparation of the gold film and then a deposition potential of +0.2 V vs Ag/AgCl for the preconcentration of mercury. An on-line medium exchange method was included in the injection step to reduce the effect of chloride ions, whilst a solid phase extraction cartridge was used to remove interference for copper(II) ions. The flow pattern of the sequentially injected solutions with the synchronized two-step deposition potentials did not significantly affect the detection of Hg2+. Square wave parameters of a 4 mV step potential, 150 Hz frequency and 30 mV amplitude gave an optimal Hg2+ detection sensitivity with a limit of detection of 0.22 μg L-1 (sample volume of 0.9 mL) without any significant interference effect. This method was successfully applied to determine Hg2+ concentrations in real water samples, including in the chloride-rich samples of sea water and table salt, with very good accuracy (recovery in the range of 96.0-101%).
AB - A computer-controlled system, included a sequential injection system and an electrochemical detector, was developed for the determination of mercury(II) ion (Hg2+) concentrations. The screen-printed carbon electrode (SPCE), a well-known low-cost electrode, was modified by overlaying in situ with a gold film (Au-SPCE). Square wave anodic stripping voltammetry (SWASV) using the Au-SPCE was performed with a two-step deposition potential of an initial -0.5 V vs Ag/AgCl for the preparation of the gold film and then a deposition potential of +0.2 V vs Ag/AgCl for the preconcentration of mercury. An on-line medium exchange method was included in the injection step to reduce the effect of chloride ions, whilst a solid phase extraction cartridge was used to remove interference for copper(II) ions. The flow pattern of the sequentially injected solutions with the synchronized two-step deposition potentials did not significantly affect the detection of Hg2+. Square wave parameters of a 4 mV step potential, 150 Hz frequency and 30 mV amplitude gave an optimal Hg2+ detection sensitivity with a limit of detection of 0.22 μg L-1 (sample volume of 0.9 mL) without any significant interference effect. This method was successfully applied to determine Hg2+ concentrations in real water samples, including in the chloride-rich samples of sea water and table salt, with very good accuracy (recovery in the range of 96.0-101%).
KW - Mercury determination
KW - On-line medium exchange
KW - Screen-printed carbon electrode
KW - Sequential injection analysis
KW - Square-wave anodic stripping voltammetry
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U2 - 10.1016/j.jelechem.2014.05.026
DO - 10.1016/j.jelechem.2014.05.026
M3 - Article
AN - SCOPUS:84903635196
SN - 0368-1874
VL - 727
SP - 78
EP - 83
JO - Journal of Electroanalytical Chemistry
JF - Journal of Electroanalytical Chemistry
ER -