Chromium(III) determination without sample treatment by batch and flow injection potentiometry

Area of Science:

• Analytical Chemistry
• Environmental Science
• Materials Science

Background:

• Direct detection of chromium(III) is challenging due to complex sample matrices.
• Existing methods often require tedious sample preparation steps like oxidation/reduction or preconcentration.
• There is a need for a simplified and efficient analytical device for chromium(III) determination.

Purpose of the Study:

• To design and evaluate a new, easy device for direct detection of chromium(III).
• To develop a potentiometric sensor with a solid-state membrane based on a carbon paste matrix.
• To optimize and validate the sensor's performance in both batch and flow analysis modes.

Main Methods:

• Fabrication of a carbon paste matrix-based potentiometric sensor.
• Modification of the sensor membrane with di(2-hydroxyphenylimino)ethane.
• Optimization of analytical parameters for potentiometric response in static and on-line analysis.
• Testing the sensor with a sediment Certified Reference Material and environmental/industrial samples.

Main Results:

• The developed sensor achieved optimal detection limits of 1.4 x 10(-7)M (static) and 5.4 x 10(-7)M (on-line).
• High selectivity for chromium(III) was demonstrated in both batch and flow analysis modes.
• Successful determination of chromium(III) in real samples, including sediment, soil extracts, and electroplating wastewater, was achieved.

Conclusions:

• The novel potentiometric sensor provides a direct, efficient, and selective method for chromium(III) detection.
• The device eliminates the need for prior oxidation/reduction or preconcentration steps, simplifying analysis.
• This technology is applicable for the reliable determination of chromium(III) in diverse environmental and industrial matrices.