质谱检测用同位素^(15)N标记样品的处理方法

Treatment Methods of Isotope ^(15)N Labeled Sample for Mass Spectrometry

采用质谱法分析稳定同位素15N标记化合物的15N丰度,进样形式为氮气时,具有记忆效应小、不发生同位素分馏的优点,因此,待测样品处理方法非常关键。选用具有代表性的15N无机标记化合物和15N有机标记化合物进行了次溴酸盐氧化还原法、半微量的消化-氧化还原联用法和微量的高温燃烧法等样品处理方法的条件试验,消除了样品转化处理过程中的同位素分馏效应和记忆效应的影响,样品的检测结果准确度和精确度令人满意,误差小于±0.05%。研究得到了具有可行性的样品转化条件和操作方法。采用数理统计方法对得到的质谱检测数据进行检验,获得了满意的结果。

Mass spectrometry was developed to determine the enrichment of stable isotope ^15N labeled compounds in which the treatment of samples are crucial. Nitrogen as sample forms has the advantages of smaller memory effect and no isotope fraetionation. Typical ^15N inorganic and organic compounds were chosen for the research of sam pie treatment by the methods of hypobromite redox reaction, semi-micro digestion redox reaction and microscale high temperature combustion method. Isotope fraetionation and memory effects occurred in conversion of samples were eliminated and the accuracy and precision of the results were satisfying. In the research feasible sample conversion condi tions and operation procedure were obtained. Mass spectrometry data were tested by mathematical statistics with satisfactory result.