9503257 HATCHER Although dissolved organic carbon (DOM) in the oceans plays a major role in the global biogeochemical cycling of carbon, we know little of its known composition and origin. Terrestrial contribution to the DOM has traditionally been estimated from analytically determined amounts of lignin-derived materials produced from oxidative degradation by CuO. Recently, a new thermal degradative technique has emerged as a powerful tool to examine the chemical components of lignin. This proposed study seeks to develop and evaluate this technique for the characterization of lignin in DOM from marine and riverine systems. Aside from showing greater specificity for lignin-derived material, the method (thermolysis/gas) chromatography with teramethyl ammonium hydroxide) is easily implemented in most modern laboratories, in contrast to the traditional CuO oxidation. Similar lignin phenol parameters are obtained and the technique is believed to recover the lignin signature from samples which have been extensively degraded, unlike the CuO method. If this method is tested to compare well with the CuO procedure, it would provide a rapid and more easily applied method of evaluating the terrestrial composition of marine and riverine DOM.
