稳定性同位素技术课件.ppt

稳定性同位素技术,浪性同位名生感究中的应黄建辉中国科学院植物研究所2004-11-6,什么是同位素?HOHDODOHDO或者D21O,Isot olMass(protons+neutrons)=12StableIsotope:13CMass=13Stablea5Isotope:14CMassUnstable,half-life5,730 yearso neutrono eleectron,SOMETIMES THE EXTRA NEUTRON MAKESA DIFFERENCE.ITS HARDER TO PUSH THEHEAVY MOLECULES UP AN ENERGY HILL7 MADE(MADE/THEAVY GOINGENERGYCM.Fogel and B.Fry,Woods Hole Stable Isotope Workshop,1986,LInenSoup ralioNatural abundanceNatural abundanceHvdrogenH=y呢of stable isotopesCarbyNNOx gSphursOph 3ph34Hobson 1999 Oecologia,mass 46 For Co2,threecollectors areand 4d Several masses are collectedIn the flight tube the magnet causes the ions to be deflected,with a radusof thHeavier ions are deflected lessexample,for CO2,mass 46 has the lar gest radus of deflection,mass 44has the smallest,and mass 45 is intermediate.Charge also affects thedius of deflection,but.for the most part-Lhms is held constant becausethe lon Source strips only i electron from most moleculeFigure 1.Dispersion patt en in the flight tube of a mass sp ectr ometer for the three most common massesfcO2,mase44(12c,100.16Cthe ion source,each molecule is stripped of 1 electron,becaming a positively charged ion when it entersche flight tubeColoradoStableiSotopeLab,Nau,Url:jan.uccnauedu/-bah/cpsil.html,IRMS:isotope ratio mass spectrometer200,常用稳定性同位素种类2H(D)同位素13C同位素15N同位素180同位素,8”符号8X=Rm/kmd)-11x1000X代表3C,15N,34S,R为重轻同位素比例,Cn2C,15N/434S/2S83C=13C/2C samlx100013C/12C standard物质中的同位素含量0.011时,81C1,否则1同位素的标准物质C,Pee Dee Belemnite(PDB),C/2C=0.01 12372N,大气15N/4N=0.0036765,分差COz(air)t Co2(leaf)-Carboxylation(Ps)sourCe稳定性同位素比例的变化羧化作用快:813C=-7=-4813C=-11慢:813C=-7=-29813C=-35例如:陆地C3植物,8C=-28大气=-7.4,=-20.4实际上,=-21,C3植物813C=-28对陆生的动物来说,C分差通常比较小,=01ATMOSPHERE0Soil Organic Matter-26M352CO2-15Tropical C-Total DissolvedDOM-23LAKEOCEAN,6、最大的骄傲于最大的自卑都表示心灵的最软弱无力。斯宾诺莎7、自知之明是最难得的知识。西班牙8、勇气通往天堂，怯懦通往地狱。塞内加9、有时候读书是一种巧妙地避开思考的方法。赫尔普斯10、阅读一切好书如同和过去最杰出的人谈话。笛卡儿,Thank you,拯畏怖汾关炉烹霉躲渠早膘岸缅兰辆坐蔬光膊列板哮瞥疹傻俘源拯割宜跟三叉神经痛-治疗三叉神经痛-治疗,