Low-level mercury determination with thiamine by fluorescence optosensing

Area of Science:

• Analytical Chemistry
• Environmental Science
• Chemical Sensing

Background:

• Mercury(II) (Hg(II)) is a toxic heavy metal pollutant in aquatic environments.
• Accurate and sensitive detection methods for Hg(II) are crucial for environmental monitoring.
• Existing methods may face challenges with specificity and complex sample matrices.

Purpose of the Study:

• To develop a sensitive fluorescence optosensing method for Hg(II) determination in water samples.
• To optimize the sensing parameters for enhanced performance.
• To evaluate the method's specificity and applicability to real-world water samples.

Main Methods:

• Utilized a flow injection technique with a non-ionic-exchanger solid support.
• Immobilized thiochrome, formed by thiamine oxidation with Hg(II), in a flow cell.
• Optimized experimental parameters including carrier pH, thiamine concentration, and flow rate.

Main Results:

• Achieved a detection limit of 3 ng/ml for Hg(II) with a 4-ml sample injection.
• Demonstrated high specificity for Hg(II) in the presence of common interfering ions like Mg(II) and Ca(II).
• Showed a low relative standard deviation of ±3.0% for replicate analyses.

Conclusions:

• The developed fluorescence optosensor provides a sensitive and selective method for Hg(II) detection.
• The method is robust and suitable for analyzing Hg(II) in diverse water samples, including mineral, tap, and sea water.
• This approach offers a valuable tool for environmental water quality assessment.