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对于卟啉碳同位素的测定 ,传统方法 (用HPLC分离出单个卟啉化合物 ,然后燃烧成CO2 进行碳同位素的测定 )需要的样品量大 (几mg)、耗时长 ,限制了其在化学、地球科学中的应用。该文作者建立的方法是通过对卟啉化合物进行衍生化反应 ,以增强卟啉的挥发性 ,使其适用于气相色谱 同位素比值质谱 (GC IRMS)技术。对衍生化反应的整个过程进行了同位素测定 ,证实最终的衍生化硅卟啉与初始的自由基卟啉化合物碳同位素的差值在分析误差范围之内 ,无明显的同位素分馏。混合卟啉标样同位素的对比研究显示 ,在整个衍生化过程中各单体卟啉间无同位素交换分馏现象 ,可应用于卟啉碳同位素的分析。该技术的优点在于需要的样品量小 (几 μg)、时间短 ,平均偏差小。
For the determination of porphyrin carbon isotopes, the traditional method (separation of individual porphyrins by HPLC and subsequent combustion to carbon dioxide for carbon isotope determination) requires a large sample size (a few mg) and takes a long time, limiting its use in chemistry, Application in science. The author of the paper established the method by derivatization of porphyrin to enhance the volatility of porphyrin and make it suitable for gas chromatography-mass spectrometry (GC-IRMS). The whole process of derivatisation was measured by isotope. It was confirmed that the difference between the final carbon derivatized silicoporphyrin and the carbon isotope of the free radical porphyrin compound was within the analysis error range, and no obvious isotopic fractionation was found. The comparative study of mixed porphyrin standard isotopes shows that there is no isotopic exchange fractionation between the porphyrins of all monomers during the whole derivatisation process and can be applied to the analysis of carbon isotopes of porphyrin. The advantage of this technique is the small sample size (a few micrograms) required, the short time, and the small average deviation.