作　　者： ; ; ; ; ; ; ;

机构地区： 中国科学院广州地球化学研究所有机地球化学国家重点实验室

出　　处： 《分析化学》 2006年第6期773-777,共5页

摘　　要： 利用单体化合物稳定同位素（CSIA）技术研究了甲醛合次硫酸氢钠（HMSNa）与半胱胺衍生化过程的同位素效应,探讨了半胱胺衍生化法测定大气甲醛碳同位素的可行性.为了评价实验的稳定性与精确度以及衍生化过程的同位素效应,本实验采用不同同位素组成的HMSNa在酸性条件下分解,分解后的甲醛在碱性条件下与不同摩尔比的半胱胺反应,研究了该衍生化过程的反应条件和同位素效应.研究结果表明,HMSNa在pH值为1～2,60 ℃条件下分解,分解后的甲醛在PH值为8～9的条件下与摩尔比1： 20到1： 30半胱胺反应,该衍生化条件较为理想且该过程不存在同位素分馏;实验重现性好,测定精度高;可以用于大气甲醛同位素组成分析. The isotope effects of HOCH2SO3Na （HMSNa） derivatization and cysteamine were preliminary studied by compound-specific isotope analysis （CSIA）. The feasibility for the determination of isotopic composition of atmospheric formaldehyde was discussed. In order to evaluate the reproducibility, the accuracy and the carbon isotope effects during derivatization procedures, the optimum derivatizative conditions of the procedures were studied. Three HMSNa with different δ^13C values were used to study the isotope effects of the procedures. The HMSNa was decomposed under the acid condition and the formaldehyde decomposed was derivated by cysteamine in the basic solution. The results showed that the reaction conditions were fairly good and no carbon isotopic fractionation occurred when the HMSNa was decomposed and derivated with pH 1 -2 and 8 - 9, respectively in the solution of the mole ratio with 1 ： 20 to 1： 30 for the formaldehyde to cysteamine. The accuracy and precision of the method are of the same quality as the reproducibility of the measurements. The error analysis also showed that the deviation of the analysis could be ignored, and the method could be used to determine the δ^13C values of atmospheric formaldehyde.

关 键 词： 甲醛 亚硫酸氢钠 半胱胺 噻唑烷 同位素

领　　域： [轻工技术与工程] [轻工技术与工程] [天文地球] [天文地球]