Sharpening the Focus on Earth's Carbon Cycle: Advanced Technique Decodes Dissolved Organic Matter

Dissolved organic matter (DOM) plays essential roles in aquatic ecosystems—from offering UV protection to participating in carbon cycling—yet its complex molecular nature has long posed challenges for detailed analysis. This study presents an optimized analytical method that improves DOM characterization for various ecosystems, enabling more precise environmental monitoring and reliable comparisons across laboratories.

A research team led by Prof. WANG Faming (South China Botanical Garden, CAS), in collaboration with the China National Analytical Center (Guangzhou), the Guangzhou Institute of Geochemistry (CAS), East China Normal University, and Harvard University, optimized Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to improve signal quality and ensure better reproducibility across laboratories. Published in Limnology and Oceanography: Methods, the study provides practical guidance for extracting more detailed molecular data—even from widely available instruments with lower magnetic field strengths (7T, 9.4T, and 12T).

By analyzing samples from multiple ecosystems, the team developed protocols to fine-tune resolution and enhance DOM fingerprinting. “You don’t have to upgrade the instrument to ultra-high magnetic fields, which can incur costs (e.g., 7T to 15T-FT-ICR MS) reaching tens of millions of RMB,” said Prof. GAN Shuchai, the study’s first author. “This approach is designed to work effectively with widely available instruments, offering a practical alternative.”

This study also introduced standardized coefficient-of-variation ranges that allow consistent comparison of dissolved organic matter (DOM) across different laboratories. Even when using instruments of varying resolution, the optimized method improves detection of ecologically significant molecules and increases reproducibility among labs.

By providing a unified analytical framework, this work supports greater data sharing and reliability in DOM studies. It also establishes a foundation for high-resolution “environmental omics” research, enabling more accurate tracking of carbon flow in aquatic ecosystems. https://doi.org/10.1002/lom3.10696

Fig . Diagram (Enlargement of ~0.2 m/z segments) showing the influence of parameter settings on the characteristics of dissolved organic matter (DOM) "fingerprints". (Image by WANG et al.)