Simple and rapid analytical method for the determination of methylmercury in fish and shellfish using solid-phase extraction and gas chromatography–mass spectrometry

Abstract

Herein, we devise a method to detect methylmercury (MeHg) in fish and shellfish food samples using solid-phase extraction. We draw from the principles of the “QuEChERS” method, eliminating the need for hazardous organic solvents and employing general-purpose gas chromatography–mass spectrometry (GC–MS) equipment. The use of acetonitrile during extraction prevents emulsion formation, which could otherwise disrupt MeHg recovery. Additionally, the introduction of sulfuric acid solution during extraction dissolves sample lipids. The purification process involves solid-phase extraction instead of liquid–liquid extraction, ensuring rapid and straightforward analysis. The MeHg recovery, analyzed using reference samples and MeHg-loaded blank samples, is 86.1 %–98.3 %, and the limit of quantification is 0.02 mg/kg. The calibration curves for phenyl-derivatized MeHg exhibit exceptional linearity at 1–50 ng/mL. The intra- and inter-assay coefficients of variation validate the repeatability and intermediate precision of our method. This analytical approach is simple, and it offers high precision and accuracy, making it valuable for quantifying MeHg in fish and shellfish food samples.