Evaluating Lignin Chemistry of Coastal Wetland Plants and Soil Organic Matter Using Cuo Oxidation and Py-GC/MS Methods.

Lignin is a primary component of plant cell wall structure and is the most abundant organic substance, next to cellulose, on earth. The degradation and transformation of lignin in soil provides the information that is fundamental to the understanding of soil organic matter degradation pathway in a specific ecosystem. The aim of this study was to evaluate lignin chemistry of wetland plants and soil organic matter using Cuo oxidation and Py-GC/MS methods. Dominant wetland plants and soil core samples from different coastal wetland ecosystems were collected and sectioned. The Py-GC/MS analysis of samples was performed with and without tetramethylammonium hydroxide (TMAH) and compared with CuO oxidation method. Ratios of different lignin monomers were calculated and evaluated. In general, results showed close relations between plant source lignin chemistry and soil organic matter molecular composition.  The Py-GC/MS results were consistent with those obtained using the CuO oxidation method.