tailieunhanh - Hydrolysis of polysaccharides with 77% sulfuric acid for quantitative saccharification

Classical standard hydrolysis of polysaccharides with 72% sulfuric acid was modified in 2 manners. In order to avoid treatment in an autoclave at 120 °C under pressure, wood or pulp material was first swollen in cold 77% acid followed by hydrolysis steps in diluted acid solutions. | Turk J Agric For 27 (2003) 361-365 © TÜB‹TAK Hydrolysis of Polysaccharides with 77% Sulfuric Acid for Quantitative Saccharification Günefl UÇAR*, Mualla BALABAN ‹stanbul University, Faculty of Forestry, Department of Wood Chemistry, Bahçeköy, ‹stanbul - TURKEY Received: Abstract: Classical standard hydrolysis of polysaccharides with 72% sulfuric acid was modified in 2 manners. In order to avoid treatment in an autoclave at 120 °C under pressure, wood or pulp material was first swollen in cold 77% acid followed by hydrolysis steps in diluted acid solutions. Further, the neutralization of the hydrolyzate with dilute barium hydroxide was carried out in heated mother liquor ensuring a crystalline precipitate of barium sulfate. Digestion enables the separation of clear aliquots by decantation in large amounts for analysis by HPLC. The modified procedure allows hydrolyses of polysaccharides with low losses as indicated by correction factors between and for 5 sugars, . glucose, xylose, mannose, galactose and arabinose. Key Words: quantitative saccharification, acid hydrolysis, polysaccharides, wood, pulp, HPLC Kantitatif Sakkarafikasyon Amac›yla Polisakkaritlerin % 77’lik Sülfürik Asit ile Hidrolizi Özet: Polisakkaritlerin % 72’lik sülfürik asitle klasik hidrolizi 2 aç›dan de¤ifltirilmifltir. Otoklavda bas›nç alt›nda 120 °C deki ifllem yerine odun veya selüloz örne¤i ilk önce so¤ukta % 77’lik asit ile muamele edilmifl ard›ndan hidrolize, seyreltik asit koflullarda devam edilmifltir. Daha sonra hidrolizat seyreltik barium hidroksit ile nötralize edilerek, oluflan barium sülfat›n ana çözeltiden iyi bir flekilde çökmesi sa¤lanm›flt›r. Böylece berrak ana çözeltiden dekantasyonla belli bir miktar nötral çözelti al›narak HPLC de analiz edilmifltir. Modifiye hidroliz yöntemiyle odun polisakkaritlerinin çok küçük kay›plarla hidrolizi mümkün hale gelmekte ve ilgili düzeltme faktörleri hidroliz ürünü befl fleker, glukoz, ksiloz, mannoz, galaktoz ve .