On-line microplasma decomposition of gaseous phase interference for solid sampling mercury analysis in aquatic food...

Area of Science:

• Analytical Chemistry
• Environmental Science

Background:

• Gaseous phase interference complicates mercury determination in solid samples.
• Traditional methods often require extensive sample pre-treatment and can be time-consuming.

Purpose of the Study:

• To develop a novel solid sampling mercury analyzer utilizing dielectric barrier discharge (DBD).
• To enable sensitive and rapid mercury determination in aquatic food samples with reduced interference.

Main Methods:

• A coaxial DBD reactor was integrated into a mercury analyzer, replacing conventional catalytic pyrolysis furnaces.
• The system included an electrothermal vaporizer (ETV), DBD reactor, gold-coil Hg trap, and atomic fluorescence spectrometer (AFS).
• On-line decomposition of solid food samples (up to 12 mg) was performed at ambient temperature.

Main Results:

• The method achieved a detection limit (LOD) of 0.5 μg/kg for mercury.
• Relative standard deviations (RSDs) were within 5% for standards and 10% for real samples.
• Analysis time was reduced to under 5 minutes with low power consumption (40 W).

Conclusions:

• The DBD-based analyzer offers a sensitive, precise, and rapid method for mercury determination in aquatic food.
• This approach is greener, safer, and more efficient than traditional methods, obviating chemical reagents.
• The DBD apparatus shows potential for miniaturization and portability in mercury analysis instrumentation.