Comparison of Atomic Fluorescence Spectrometry and Cold Atomic Absorption Spectrometry for Total Mercury Determination in Soil

Overview

Qin et al. (2025) conduct a comparative evaluation of two standard methods for total mercury (tHg) determination in soil: atomic fluorescence spectrometry (AFS, a method widely used in China and Asia-Pacific) and cold atomic absorption spectrometry (CAAS), also referred to as cold vapor AAS (CV-AAS). The paper provides LOD and LOQ data for both methods and evaluates agreement, precision, and applicability.

Key numbers

AFS LOD: 0.0006 mg/kg (0.6 µg/kg, or 0.6 ppb) in soil.

CAAS LOD: 0.06 µg/kg (reported as 0.06 µg/kg) — approximately 0.06 ppb in soil.

Note: These LODs apply to soil matrices, not food matrices directly. Food matrix LODs would differ due to different digestion procedures and matrix interferences.

Methods (brief)

Comparative method validation study: AFS vs. CAAS for tHg in soil. Both methods use microwave or acid digestion followed by reduction of Hg2+ to Hg0 and detection by cold vapor (CAAS) or fluorescence (AFS). CC BY license. Soil matrix; not directly food-matrix LODs but relevant to understanding method performance for environmental samples associated with food chain contamination.

Implications

Testing: AFS and CAAS are the two dominant methods for mercury (Hg) determination in environmental and agricultural matrices in Asia (particularly China). Understanding the comparative performance of these methods is relevant to interpreting the large body of Chinese literature on mercury in food and agriculture. AFS LOD of 0.6 µg/kg in soil indicates high sensitivity; analogous food matrix methods (using thermal decomposition amalgamation AAS, TDA-AAS) typically achieve even lower LODs. Relevant background for the wiki’s testing method pages.

Related evidence

• Mercury analytical methods

Update history

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