Quantification of Hexavalent Chromium in Surface Water Samples by a Selective Electrochemical Method

Area of Science:

• Analytical Chemistry
• Electrochemistry
• Environmental Science

Background:

• Hexavalent chromium (CrVI) is a toxic environmental pollutant.
• Accurate detection methods for CrVI are crucial for water quality assessment.

Purpose of the Study:

• To develop a robust, selective, and sensitive voltammetric method for CrVI detection.
• To utilize a chemically modified carbon paste electrode for enhanced CrVI analysis.

Main Methods:

• A carbon paste electrode was modified with graphite powder and diphenylcarbazone.
• Voltammetric parameters including electrolyte type, pH, and accumulation conditions were optimized.
• The method's performance was evaluated for linearity, reproducibility, and detection limits.

Main Results:

• The method showed a linear response for CrVI concentrations from 0.20 to 2.60 µmol/L.
• High reproducibility was achieved with relative standard deviations (RSDs) below 2.0%.
• The limit of detection (LOD) and limit of quantification (LOQ) were determined to be 0.052 and 0.174 µmol/L, respectively.

Conclusions:

• The developed voltammetric method is effective for sensitive and selective CrVI determination.
• The modified electrode demonstrated good stability without significant passivation.
• The method was successfully applied to analyze CrVI in real surface water samples.