| Objective: To address the limitations of existing studies predominantly focused on single food matrices and the inefficiency of traditional pre-treatment methods for total mercury determination, this study aimed to establish a high-efficiency and accurate analytical method for total mercury content in foods, systematically validate its applicability to complex matrices, and fulfill the regulatory requirements for food safety monitoring.Methods: A direct mercury analysis method was developed based on catalytic pyrolysis-gold amalgamation atomic absorption spectroscopy. By stepwise optimization of pyrolysis temperatures (150°C/550°C for low-concentration ranges and 200°C/650°C for high-concentration ranges) and carrier gas flow rates (150–200 mL/min), plant-derived samples (e.g., rice, jujube), animal-derived samples (e.g., snakehead, fish meal), and 14 types of food samples were analyzed. The method"s detection limit, accuracy, stability, and spike recovery were evaluated to assess its performance and matrix applicability.Results: The method established dual linear calibration curves of 0–10 ng and 25–200 ng, with correlation coefficients of 0.9993 and 0.9998, respectively. The limit of detection (LOD) and limit of quantification (LOQ) were 0.0002 mg/kg and 0.0005 mg/kg, respectively. Spike recoveries ranged from 90% to 116%, with relative standard deviations (RSD) ≤5%. The method was systematically validated for complex matrices, including plant-derived, animal-derived, and processed foods, with all results complying with the GB 2762–2022 National Food Safety Standard: Limits of Contaminants in Foods.Conclusion: The proposed method eliminates the need for chemical digestion in sample pretreatment, significantly shortens the analytical time, and prevents mercury volatilization losses. It overcomes the limitations of single-matrix analysis and achieves rapid total mercury detection in diverse complex food matrices, thereby providing an efficient and reliable technical solution for food safety risk monitoring and regulatory compliance. |
