^(13)C-尿素同位素丰度的检测方法

Analytical Method for Isotope Abundance of ^(13)C-urea

为更好地控制13C-尿素试剂中13C的有效含量,研究了用亚硝酸氧化法和高温灼烧法将13C-尿素样品转化为气体同位素质谱检测用样品气的方法与条件。结果显示,亚硝酸钠法用2 mg13C-尿素样品,高温灼烧法用1 mg13C-尿素样品,转化得到的13CO2气体即可满足质谱计检测。实验探索了亚硝酸钠试剂的使用量,制备样品气的反应温度与反应时间的确定、氧化铜试剂的处理效果等条件,完成了高丰度13C-尿素的检测,确定了检测数据的计算与表述,得到了标准偏差小于±0.07%的理想检测结果。

In order to better control the effective content of ^13C- in ^13C-urea reagent, the technique and the conditions for converting ^13C-urea sample into the sample gas used in gas isotopic mass spectrometry detection by means of nitrite oxidation method and high temperature burning method were investigated. The results showed that the ^13CO2 gas obtained from nitrite oxidation method with 2 mg ^13C-urea samples and that from high temperature burning method with 1 mg^13C-urea samples can satisfy the demand of the mass spectrometer detection. The sodium nitrite reagent dosage, the reaction temperature and the reaction time of the sample gas preparation, as well as the treatment effect of copper oxide reagent etc. were sought experimentally. The high abundance ^13C-urea testing was completed, the calculation and expression of the detection data were also determined, and the standard deviation were less than ±.07%.