Open AccessElectrochemical Behaviour of Gold Thin Film Glassy Carbon Electrode for Determination of Chromium(VI)
Author(s) -
Nevila Broli,
Loreta Vallja,
Majlinda Vasjari,
Alma Shehu,
Sonila Duka
Publication year - 2021
Publication title -
asian journal of chemistry/asian journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.145
H-Index - 34
eISSN - 0975-427X
pISSN - 0970-7077
DOI - 10.14233/ajchem.2021.23121
Subject(s) - chemistry , chromium , analytical chemistry (journal) , detection limit , calibration curve , supporting electrolyte , anodic stripping voltammetry , electrochemistry , stripping (fiber) , glassy carbon , electrode , electrolyte , cyclic voltammetry , materials science , chromatography , organic chemistry , composite material
A modified glassy carbon electrode (Aufilm/GCE) using a gold film was constructed for determinationof chromium(VI) in real water samples. A GCE was immersed in HAuCl4 solution (10-3 M) and thethin layer of gold was electrodeposited for 10 min at −0.4 V (vs. Ag/AgCl). Compared with only GCE,a strong affinity between chromium and gold species was observed with an increase in Cr(VI) signal.The type of supporting electrolytes, electrodeposition time, scan rate, pH, modulation time and themodulation amplitude were optimized through differential pulse-anodic stripping voltammetry(DP-ASV). A calibration graph acquired using the accumulation time of 120 s with a sensitivity of 1.3× 10-2 μA/μgL-1 was linear in the range of 10-120 μg L-1. A low detection limit of 5.5 μg/L Cr(VI) anda strong correlation coefficient R2 = 0.9971 were obtained under the optimal experimental conditions.Signals were reproducible and exhibited a relative standard deviation of ±4.5%. A modified sensorwas employed to determine the Cr(VI) content in the sewage water samples.