wiley and sons p 124 possibly due to the ammonolysis of the acetyl groups in hemicellulose see e g o 39 connor j j 1972 tappi 55 353 ftir atr spectroscopy had been a severely limited technique in the past due to the unavailability of hard crystals which were chemically inert and optically transparent in the visible and most of the mid ir region however with the introduction of atr cells utilizing diamond and silicon based crystals this technique has made rapid strides in the past few years the solid biomass samples can now be pressed onto the atr crystal at high pressures allowing a more uniform penetration by the evanescent radiation and a higher degree of spectral reproducibility no grinding is necessary for solid samples facilitating ease and speed in sample preparation more importantly with the improved spectral data collection and reproducibility associated with the present day ftir atr technique it is now possible to develop a better quality database for biomass compositional analysis see e g tucker m p nguyen q a eddy f p kadam k l gedvilas l m webb j d 2001 fourier transform infrared quantitative analysis of sugars and lignin in pretreated softwood solid residues appl biochem biotechnol 91 93 51 61 the atr procedure rapidly identifies the chemical changes upon pretreatment approximately 6 8 and 13 15 by mass based on dry biomass of the untreated and afex treated corn stover respectively were lost in the washing step a small fraction of the washed material was biomass fines lt 0 1 while the remainder of the extract was possibly ligno phenolic fragments proteins sugars xylooligosaccharides etc the weight loss of the biomass samples was taken into account for the hydrolysis calculations these results are found to be consistent with previously reported water wash.