岩矿测试2017，Vol.36Issue(4)：327-339,13.DOI:10.15898/j.cnki.11-2131/td.201611190174
高灵敏度元素分析仪-连续流同位素质谱法对硅酸盐岩中碳及碳同位素组成的精确测定
Precise Measurement of Carbon Concentration and Isotopic Ratios in Silicate Rocks by a High Sensitivity Elemental Analyzer Coupled with a Continuous Flow Isotope Mass Spectrometry
摘要
Abstract
The precise and accurate analyses of minor carbon in silicate rocks can provide valuable insights into the origin of fluid and formation processes.The Elemental Analyzer-Isotope Ratio Mass Spectrometry (EA-IRMS) is a quick analytical method using small quantities of sample.In this study, EA-IRMS is applied to analyze carbon isotopic composition of trace carbon in silicate rock.Based on a series of tests, the key analytical parameters are confirmed.The normalization procedure and reference materials selection are as follows.① Selection of standard materials with a wide carbon isotope composition range and reasonable carbon isotope distribution.Preparation of the mixtures of reference materials and super quality quartz power.② A calibration curve was established using the measured values and certified values of the three reference materials similar to the samples.The measurement of natural samples is normalized to achieve an accurate determination of trace carbon content as low as 600 μg/g in silicate rocks and carbon isotopic composition.National standard material GBW04416 is used as an unknown sample to test the linear equations regressed with different contents.When the carbon content is no lower than 600 μg/g, the standard deviations are 0.02‰, 0.04‰, 0.05‰,-0.07‰, 0.11‰, respectively.For the mixture of MERCK and USGS24, the determined carbon isotopic composition and carbon content are comparable with the true value within analytic uncertainty.Therefore, the high precision and accuracy of carbon isotopic composition can be obtained for carbon content no less than 600 μg/g in 30 mg silicate rock.The carbon content of the sample was established based on the linear curve established by the peak area (peak intensity) of the standard mixture of different carbon contents and the corresponding content.Analytic uncertainty of carbon content of the sample is within 10%.关键词
元素分析仪/碳含量/碳同位素比值/硅酸盐岩Key words
elemental analyzer/carbon concentration/carbon isotope ratio/silicate rocks分类
化学化工引用本文复制引用
查向平,龚冰,郑永飞..高灵敏度元素分析仪-连续流同位素质谱法对硅酸盐岩中碳及碳同位素组成的精确测定[J].岩矿测试,2017,36(4):327-339,13.基金项目
中央高校基本科研业务费专项资金资助(WK3410000007) （WK3410000007）
