纖維素提取方法

纖維素提取方法簡(jiǎn)介Howcouldweextractcellulosefromtreering-stepbystepPeiliFU(付培立)March14th2014referencesWielochT,HelleG,HeinrichI,etal.Anoveldeviceforbatch-wiseisolationofα-cellulosefromsmall-amountwholewoodsamples[J].Dendrochronologia,2011,29(2):115-117.LaumerW,AndreuL,HelleG,etal.Anovelapproachforthehomogenizationofcellulosetousemicro‐amountsforstableisotopeanalyses[J].RapidCommunicationsinMassSpectrometry,2009,23(13):1934-1940.主要步驟MainproceduresCrossdatingandSamplecutting;ExtractionHomogenizationFreezedryingWeighingandmeasuredwithmassspectrometry.樣品的切取和稱(chēng)量

Cuttingandweighing

樣品大?。汉穸萾hickness0.5-0.8mm;samplesize>500μm樣品量sampleamount：＞2mg

Samplesneededformassspectrometry:

onemeasurementof:C130.5mg；O180.3mg；

(production~30%)提取extractionNaOH5%solution溶液,60℃,2h,2times次;

（近沸騰熱的去離子水，洗3次,washed3timeswithboiledde-ionedwater）NaClO27%solution溶液,60℃,8h,6times（醋酸溶液aceticacid,調(diào)節(jié)pH至4-5）;

（近沸騰熱的去離子水，洗3次,washed3timeswithde-ionedboiledwater）NaOH17%solution溶液,室溫(roomtemperature),2h,2times次

（1%HCl溶液洗1次，近沸騰熱的去離子水，洗3次測(cè)pH,washedwith1%HCl,thenwashed3timeswithde-ionedboiledwater）判斷是否提取完全(completelyextracted?)草酸溶液:每100mlNaClO2加草酸溶液0.5~1ml草酸

aceticacidsolutions:0.5ml~1ml/100mlNaClO27%纖維素轉(zhuǎn)移cellulosetransferEppi管清洗(高壓氣體、去離子水）、加入1ml去離子水；纖維素轉(zhuǎn)移鑷子去離子水等冰箱4℃冷藏纖維素的同質(zhì)化homogenization樣品冷藏storeinrefrigerator(+4℃）方法：超聲波；ultrasonic設(shè)置：cycle0.5，amplitude6-7；繼續(xù)時(shí)間duration30s（13C2*15s18O30s

因不同物種而有所差異）；判斷呈牛奶狀(milky)，或者纖維素均一(orhomogenized蓋上帶孔的蓋子，至于冰箱中冷凍(為低溫真空干燥作準(zhǔn)備)storedinrefrigerator-10℃真空低溫干燥(freezedry)關(guān)閉排氣閥、排水閥，檢查油泵中油量多少。打開(kāi)機(jī)器和油泵預(yù)熱30分鐘（warmup）；將樣品放入，一般一次可放入3個(gè)eppi板（288個(gè)樣品左右），主干燥程序，48h；真空度atm降至1.030mbar(maindryingprocess)調(diào)節(jié)程序至干燥后程序，24h；(afterdryprocess)

真空1.030mbar降至0.003~0.005mbar調(diào)節(jié)至待機(jī)程序小心打開(kāi)排氣閥，使壓力升至1atm然后取出樣品，打開(kāi)排水閥，關(guān)閉機(jī)器和泵纖維素稱(chēng)量weighofcellulose使用半微量天平（與稱(chēng)量木材使用同一天平）精度0.01mg同位素測(cè)定premeasurement需要量theamountofcelluloseneeded:

18O300μg，13C500μg

銀（18O,Silvercapsule）或者鈦（13C,Titaniumcapsule）膠囊裹??；再次干燥：高溫、真空將所有的水除去removeallthewaterinsamples;測(cè)定：質(zhì)譜儀spectrometryDrybefroeanalysiswithmassspectrometrySamplesformassspectrometry:O18silvercapsule;C13Titaniumcapsule廢液處理ThewasteNaClO27%注意溶液有氣體產(chǎn)生,廢液應(yīng)敞口至于通風(fēng)櫥一段時(shí)間,然后再擰緊Gaswillemitfromthewaste