摘要
提供了一种可批量处理、消耗低廉的测定土壤水溶性有机碳同位素的新方法。该方法通过多水土质量比法提取土壤水溶性有机碳,得到含土壤水溶性有机碳的溶液,经磷酸酸化至pH小于2,将所得的溶液通过冷冻干燥进行浓缩,浓缩后的物质加高纯水复溶、在银舟中多次干燥富集后通过元素分析仪-稳定同位素比率质谱仪(EA-IRMS)进行δ~(13)C值测定。本方法中对多水土质量比法提取土壤水溶性有机碳的水土比例、振荡时间等参数进行了优化,将冷冻干燥的浓缩方式用于土壤可溶性有机碳同位素测定的前处理。通过土壤样品的平行测定对比,δ~(13)C的标准差小于0. 1‰,表明该方法重现性好,样品测试精密度高。
By means of a simple extraction with ultrapure water of air-dry soil samples,dissolved organic carbon was extracted. The inorganic carbon in extract was removed by adjusting the pH to less than 2 with H_3PO_4. The acidified extract was concentrated by vacuum freezing drying method. And the concentrate was re-dissolved in small amount of ultrapure water. Then the solution was dried in silver capsule for several times to accumulate enough dry mass,which can be determined by elemental analyser-stable isotope ratio mass spectrometry for δ~(13)C. The ratio( m/V) of soil to water and equilibrium time of extraction were optimized. It was noteworthy that the vacuum freezing drying method was used for the pretreatment of dissolved organic carbon in soil. The established method was applied to the analysis of δ~(13)C in soil samples. The standard deviation of six parallel determination results was 0. 1‰. This showed that the established method was accurate and reliable.
引文
[1] LG H,Zhou G S,Zhou L,Jia Q Y. J. Meteor. Environ.,2006,(2):51吕国红,周广胜,周莉,贾庆宇.气象与环境学报,2006,(2):51
[2] Zhang J S,Tao S,Cao J. Chin. J. Soil Sci.,2000,31(4):174张甲珅,陶澍,曹军.土壤通报,2000,31(4):174
[3] Liu M,Yu W T,Jiang Z S,Zhao X. Chin. J. Soil Sci.,2007,38(4):758柳敏,宇万太,姜子绍,赵鑫.土壤通报,2007,38(4):758
[4] Zhou J M,Dai J Y,Pan G X. J. Agro-Environ. Sci.,2003,22(6):731周江敏,代静玉,潘根兴.农业环境科学学报,2003,22(6):731
[5] Zhou Y,Xu X G,Ruan H H,Wang J S,Fang Y H,Wu Y Y,Xu Z K. J. Nanjing For. Univ.(Nat. Sci. Ed.).,2009,33(4):48周焱,徐宪根,阮宏华,汪家社,方燕鸿,吴焰玉,徐自坤.南京林业大学学报(自然科学版),2009,33(4):48
[6] Ding T T,Wang B Q,He R Q,Zhang Y. Res. Soil Water Conserv.,2014,21(6):72丁婷婷,王百群,何瑞清,张燕.水土保持研究,2014,21(6):72
[7] Yang X Y,Fan R Y,Wang E H,Xia X Y,Chen X W,Lu Q Q,Kong L W,Zhu H. J. Beijing For. Univ.,2013,35(5):68杨小燕,范瑞英,王恩姮,夏祥友,陈祥伟,卢倩倩,孔令伟,朱浩.北京林业大学学报,2013,35(5):68
[8] Zhou Y Z,Guo H M,Lu H. Geosci.,2015,29(2):252周殷竹,郭华明,逯海.现代地质,2015,29(2):252
[9] Lang S Q,Bernasconi S M,Früh-Green G L. Rapid Commun. Mass Sp.,2012,26(1):9
[10] Wei X G,Shen C D,Sun Y M,Yi W X. Sci. Geogr. Sin.,2003,23(4):471魏秀国,沈承德,孙彦敏,易惟熙.地理科学,2003,23(4):471
[11] Tu C L,Liu C Q,Lu X H,Yuan J,Lang Y C. Environ. Earth Sci.,2010,63(4):723
[12] Zhang Y P,Zhou A G,Zhou J W,Liu C F,Cai H S,Xu W,Liu Y D,Fang J J. Hydrogeol.&Eng. Geol.,2013,40(3):12张彦鹏,周爱国,周建伟,刘存富,蔡鹤生,徐文,刘运德,方晶晶.水文地质工程地质,2013,40(3):12
[13] H. Gandhi,T. N. Wiegner,P. H. Ostrom,L. A. Kaplan,N. E. Ostrom. Rapid Commun. Mass Sp.,2004,18(8):903
[14] L. A. Kaplan,T. N. Wiegner,J. D. Newbold,P. H. Ostrom,H. Gandhi. Freshwater Biol.,2008,53(5):855
[15] Polissar P. J.,Fulton J. M.,Junium C. K.,Turich C. C.,Freeman K. H. Anal. Chem.,2009,81(2):755
[16] Moran J. J.,Newburn M. K.,Alexander M. L.,Sams R. L.,Kelly J. F.,Kreuzer H. W. Rapid Commun. Mass Sp.,2011,25(9):1282
[17] Troyer I. D.,Bouillon S.,Barker S.,Perry C.,Coorevits K.,Merckx R. Rapid Commun. Mass Sp.,2010,24(3):365
[18] Jones D. L.,Willett V. B. Soil Biol. Biochem.,2006,38(5):991
[19] Wang Q K,Wang S L,Feng Z W,Huang Y. Acta Ecol. Sin.,2005,25(3):513王清奎,汪思龙,冯宗炜,黄宇.生态学报,2005,25(3):513
[20] Geng Z C,Dai W. Soil Science. Beijing:Science Press,2011:38耿增超,戴伟.土壤学.北京:科学出版社,2011:38