纤维素提取方法.ppt

纤维素提取方法简介 How could we extract cellulose from tree ring- step by step Peili FU (付培立) March 14th 2014 references Wieloch T, Helle G, Heinrich I, et al. A novel device for batch-wise isolation of α-cellulose from small-amount wholewood samples[J]. Dendrochronologia, 2011, 29(2): 115-117. Laumer W, Andreu L, Helle G, et al. A novel approach for the homogenization of cellulose to use micro‐amounts for stable isotope analyses[J]. Rapid Communications in Mass Spectrometry, 2009, 23(13): 1934-1940. 主要步骤 Main procedures Cross dating and Sample cutting; Extraction Homogenization Freeze drying Weighing and measured with mass spectrometry. 样品的切取和称量 Cutting and weighing 样品大小： 厚度 thickness 0.5-0.8 mm; sample size 500μm 样品量 sample amount： ＞2 mg Samples needed for mass spectrometry: one measurement of: C13 0.5mg；O18 0.3 mg； (production~ 30%) 提取 extraction NaOH 5% solution 溶液, 60℃, 2h, 2 times次; （近沸腾热的去离子水，洗3次, washed 3 times with boiled de-ioned water） NaClO2 7% solution 溶液, 60 ℃, 8h, 6 times（醋酸溶液 acetic acid, 调节pH至 4-5）; （近沸腾热的去离子水，洗3次, washed 3 times with de-ioned boiled water ） NaOH 17% solution 溶液, 室温(room temperature), 2h, 2 times次 （1% HCl 溶液洗1次，近沸腾热的去离子水，洗3次 测pH, washed with 1% HCl, then washed 3 times with de-ioned boiled water ） 判断是否提取完全( completely extracted?) 草酸溶液:每100ml NaClO2 加草酸溶液 0.5~1ml草酸 acetic acid solutions: 0.5ml~1ml/ 100ml NaClO2 7% 纤维素转移 cellulose transfer Eppi管清洗(高压气体、去离子水）、加入1ml去离子水； 纤维素转移 镊子 去离子水等 冰箱4 ℃冷藏 纤维素的同质化 homogenization 样品冷藏 store in refrigerator (+4℃） 方法：超声波；ultrasonic 设置：cycle 0.5， amplitude 6-7； 继续时间 duration 30s （13C 2*15s 18O 30s 因不同物种而有所差异）； 判断 呈牛奶状(milky)，或者纤维素均一(or homogenized 盖上带孔的盖子，至于冰箱中冷冻 (为低温真空干燥作准备) stored in refrigerator -10℃ 真空低温干燥 (freeze dry) 关闭排气阀、排水阀， 检查油泵中油量多少。打开机器和油泵预热30分钟（warm up）； 将样品放入，一般一次可放入3个eppi板（288个样品左右），主干燥程序，48h； 真空度 atm 降至 1.030mbar (main drying process) 调节程序至干燥后程序，24h；(after dry process) 真空 1.030mbar 降至 0.003~0.005mbar 调节至待机程序 小心打开排气阀，使压力升至1atm 然后取出样品，打开排水阀，关闭机器和泵 纤维素称