Monday, April 30, 2012
Napoleon Ballroom C-D, 3rd fl (Sheraton New Orleans)
Previous studies have shown that AFEXTM generates a plethora of reaction products during the deconstruction and removal of lignin from biomass (Chundawat et al., 2011, Biores Technol, 101, 8429-8438), including ferulic acid, p-coumaric acid, feruloyl amide, and coumaroyl amide. These products can have adverse effects on the enzymatic digestion of biomass and subsequent microbial conversion of the resulting sugars. In order to understand the chemistry that results in the formation of these compounds, kinetic studies of reactions involving ammonia and model esters resembling Lignin Carbohydrate Complexes (LCC) were carried out. GC-MS and LC-MS methods currently exist to analyze various pretreatment reaction products (Humpula et al., 2011, J Chrom B, 879, 1018-1022; Chundawat et al., 2011). However, due to difficulties on quantifying ammonia concentration during reaction and to minimize sample preparation, inline sampling and simultaneous analysis of reaction products was optimized using GC-TCD. In this method, a sample is taken directly from the ongoing reaction and kept at a constant temperature and pressure before being injected onto a gas chromatography column which separates the component compounds, including ammonia. Therefore, the liquid sample thermodynamic properties and compound composition remains identical to the contents of the reaction cell at each given time point minimizing analytical error.