自动石墨合成系统(AGE-3)制样方法  

Sample preparation method of automatic graphite synthesis system(AGE-3)

作　　者：何建华[1] 曹辉辉 王宗礼[1] HE Jianhua;CAO Huihui;WANG Zongli(MOE Key Laboratory of Western China’s Environmental Systems,College of Earth and Environmental Sciences,Lanzhou University,Lanzhou 730000,China)

机构地区：[1]兰州大学资源环境学院,西部环境教育部重点实验室,甘肃兰州730000

出　　处：《实验技术与管理》2021年第7期55-58,共4页Experimental Technology and Management

基　　金：兰州大学西部环境教育部重点实验室开放基金;兰州大学中央高校基本科研业务费专项资金(lzujbky-2020-kb01)。

摘　　要：基于石墨靶的加速器质谱分析是目前获得高精度^(14)C年代的最佳手段,石墨的品质直接影响年代结果的可靠性。自动石墨合成系统能够高效且精确地合成石墨,对于开展地球科学、考古学、环境科学等相关领域的研究提供技术保障。该文采用自动石墨合成系统针对不同测年材料开展了石墨制备方法研究。确定了不同材料的样品量范围;厘清了样品制备的序列,在实验过程中应遵循从老到新的年代顺序和氧化程度难易的原则;获取了不同质量样品的石墨合成效率。结果表明:反应效率随初始碳量的增加而增大,当初始碳质量大于400μg时,反应效率优于90%,同位素分馏效应微弱。国际标准物质和本底测试结果表明:标准的测试值和参考值在误差范围内一致性很好;本底的^(14)C值为0.32 pMC,^(14)C年代大于46 ka BP,仪器性能良好。Accelerator mass spectrometry based on graphite target is the best method to obtain high precision^(14)C aging,and the quality of graphite directly affects the reliability of dating results.Automatic graphite synthesis system can synthesize graphite efficiently and accurately,which provides technical support for the research of earth science,archaeology,environmental science and other related fields.In this paper,the automatic graphite synthesis system was used to study the preparation methods of graphite for different dating materials.The sample size range of different materials is determined,and the sequence of sample preparation is clarified.In the process of experiment,the principle of chronological order from the old to the new and the difficulty of oxidation degree are followed,and the graphite synthesis efficiency of different quality samples is obtained.The results show that the reaction efficiency grows with the increase of initial carbon content.When the initial carbon content is more than 400μg,the reaction efficiency is better than 90%,and the isotope fractionation effect is weak.The international reference materials and background test results show that that the standard test values and reference values are consistent within the error range,the^(14)C value of the background is 0.32 pMC,and the^(14)C aging is more than 46 ka BP.

关 键 词：自动石墨合成系统 制样方法 ^(14)C测年 

分 类 号：G482[文化科学—教育学]