Recebido em 23/7/08; aceito em 25/2/09; publicado na web em 3/7/09 VALIDATION OF METHODOLOGY FOR THE CHEMICAL CHARACTERIZATION OF SUGAR CANE BAGASSE. In this work, a methodology for the characterization of sugar cane bagasse was validated. Bagasse pre-treated with steam in a 5000 L reactor at a pressure of 15.3 kgf/cm 2 , during 7 min, was used to test the methodology. The methodology consisted of the hydrolysis of the material with H 2 SO 4 at 72% v/v, for the quantification of carbohydrates, organic acid, furfural and hydroxymethylfurfural by HPLC; insoluble lignin and ash by gravimetry; and soluble lignin by spectrophotometry. Linearity, repeatability, reproducibility and accuracy of the results obtained in two Research Laboratories were determined, and were considered to be suitable for the validation of the methodology.

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The frequency and severity of infections caused by respiratory syncytial virus (RSV) were assessed in children <2 years of age seen at the emergency department. The frequency of RSV detection in the clinical virology laboratory during the past 3 years was also analyzed retrospectively. RSV was found in 21.6% (188/869) of the samples collected from children seen at the emergency department and was found to be more frequent during the autumn, being less frequent or negligible by midwinter. RSV subgroups A and B co-circulated within the same time period in children seen at the emergency department, with varying predominance of either subgroup. There was no significant association of RSV subgroup with disease severity, but only a trend for RSV subgroup B being more frequent in children with risk factors for severe disease.

Five pilot-scale steam explosion pretreatments of sugarcane bagasse followed by alkaline delignification were explored. The solubilised lignin was precipitated with 98% sulphuric acid. Most of the pentosan (82.6%), and the acetyl group fractions were solubilised during pretreatment, while 90.2% of cellulose and 87.0% lignin were recovered in the solid fraction. Approximately 91% of the lignin and 72.5% of the pentosans contained in the steam-exploded solids were solubilised by delignification, resulting in a pulp with almost 90% of cellulose. The acidification of the black liquors allowed recovery of 48.3% of the lignin contained in the raw material. Around 14% of lignin, 22% of cellulose and 26% of pentosans were lost during the process. In order to increase material recovery, major changes, such as introduction of efficient condensers and the reduction in the number of washing steps, should be done in the process setup.

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