Optimization of the Determination of Methylmercury in Solid Matrix Samples

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Toxicology

Background:

• Accurate quantification of methylmercury (MeHg) is essential for understanding its environmental fate and toxicological risks.
• Existing methods for MeHg analysis in solid matrices can be limited in sensitivity and recovery.

Purpose of the Study:

• To develop and optimize a robust method for quantifying MeHg in solid environmental samples.
• To improve the accuracy and sensitivity of MeHg detection in sediments, soils, and sedimentary rocks.

Main Methods:

• Development of an alkaline digestion pretreatment method.
• Utilized manual purge trap coupled with gas chromatography-cold atomic fluorescence spectrometry (GC-CVAFS).
• Optimized digestion solution loading volume for enhanced detection limits.

Main Results:

• Alkaline digestion provided higher MeHg recoveries compared to acid extraction.
• Manual purge trap/GC analysis improved MeHg detection sensitivity.
• Achieved a limit of detection (LOD) of 0.0263 ng·g⁻¹ and a limit of quantification (LOQ) of 0.0876 ng·g⁻¹.
• Demonstrated relative standard deviations below 10%.

Conclusions:

• The optimized alkaline digestion-manual purge trap/GC-CVAFS method is suitable for accurate MeHg quantification in solid samples.
• This method is particularly effective for samples from environments with low mercury contamination.
• The enhanced sensitivity facilitates the study of MeHg formation, behavior, and risk assessment.