A sequential injection cold-vapor atomic absorption method for the determination of total mercury

Area of Science:

• Analytical Chemistry
• Environmental Chemistry

Background:

• Mercury contamination poses significant environmental and health risks.
• Accurate determination of mercury is crucial for monitoring and remediation efforts.
• Existing methods for mercury analysis can be complex or require specialized equipment.

Purpose of the Study:

• To develop a simplified sequential injection (SI) method for mercury determination.
• To evaluate the performance of the SI method using cold vapor atomic absorption spectrophotometry (CV-AAS).
• To compare the developed SI method with other existing SI techniques for mercury analysis.

Main Methods:

• A sequential injection system was designed, comprising a single pump, a valve, a gas-liquid separator, and a CV-AAS instrument with a quartz cell.
• Optimal conditions for mercury determination were established.
• The method was applied to the analysis of mercury in water and fish samples.
• Figures of merit, including linear calibration range, detection limit, and precision, were assessed.

Main Results:

• The developed SI method demonstrated a linear calibration range of 1.0 to 20 µg L⁻¹.
• A low detection limit of 0.46 µg L⁻¹ was achieved.
• High precision was observed, with a relative standard deviation (RSD) of 0.90% at 8 µg L⁻¹.
• The method achieved a sampling rate of one injection per 80 seconds, excluding sample pretreatment.

Conclusions:

• The presented sequential injection method offers a simple and efficient approach for mercury determination via cold vapor atomic absorption spectrophotometry.
• The method's performance, characterized by its low detection limit and high precision, makes it suitable for analyzing mercury in environmental samples.
• This SI technique provides a viable alternative to more complex flow injection methods for mercury analysis.