摘要
采用Delta V Advantage质谱仪与Gas Bench Ⅱ在线制样装置，分别用12mL和3．7mL的样品瓶，对不同质量（5～50eg）的碳酸盐标准样品（IAEA-CO-1）进行碳氧同位素组成测定。测试结果表明，当取样量小于40μg，且用12mL样品瓶进行酸化测试时，δ^13C和r^18O测量结果的内部标准偏差一半以上大于0．1‰，不能满足测试要求。当改用3．7mL样品瓶，样品取样量在15～50μg时，δ^13C的内部标准偏差为0．01‰～0．07‰，δ^18O的内部标准偏差为0．01‰～0．08‰，满足测试要求。所以，当样品量较少时，Gas BenchⅡ在线制样装置可以通过改用3．7mL样品瓶，实现对低至15μg微量碳酸盐样品的碳氧同位素精确测最。同时，碳酸盐样品的质量与峰面积具有很好的线性关系（R^2〉0．9932），表明该方法也可用于样品中碳酸盐含量的测定。
An analytical method for measuring carbon and oxygen isotopic compositions of trace amount carbonate （〉15μg） was established by Delta V Advantage isotope Ratio MS coupled with GasBench Ⅱ. Different trace amount （5-50μg） carbonate standard samples （IAEA-CO-1） were measured by GasBench Ⅱ with 12 mL and 3.7 mL vials. When the weight of samples was less than 40μg and it was acidified in 12 mL vials, most standard deviations of the δ^13C and δ^18O were more than 0.1‰, which couldn＇t satisfied high-precision measurements. When the weight of samples was grea ter than 15 μg and it was acidified in 3.7 mL vials, standard deviations for the δ^13C and δ^18O were 0. 01‰-0. 07‰ and 0.01‰-0. 08‰ respectively, which satisfied high-precision measurements. Therefore, small 3.7 mL vials were used to increase the concentration of carbon dioxide in headspace, carbonate samples even less as 15μg can be analyzed routinely by a GasBench Ⅱ continuous-flow IRMS. Meanwhile, the linear relationship between sample＇s weight and peak＇s area was strong （R^2〉0. 993 2） and it can be used to determine the carbon content of carbonate samples.
出处
《同位素》
CAS
2015年第1期41-47,共7页
Journal of Isotopes
基金
国家青年基金"河口地区硫酸盐还原过程随盐度梯度的变化规律及其控制因素"(41006072)
