关于毛细管气相色谱与质谱或保留值配合定性问题

Problems Related to the Gas Chromatographic Qualitative Analysis Using Mass Spectrometry and Retention Value Measurement

利用色谱－质谱和色谱－保留指数两种不同的定性方法，针对随机挑选的精油进行分析，利用所得结果再次强调指出色谱定性中众所周知但又未受到足够重视的一条原则，即仅靠一种方法很难对色谱峰准确定性，只有两种不同方法配合使用才能提高定性结果的可靠程度。即使质谱和保留值定性结果吻合，也只能认为获得初步的定性结果；为了确证定性结果，用标样核对有时仍属必要。

This paper stressed the importance of combining two or more methods for the compound identification in ogranic analysis. Although it is well-known that identification solely by a single method such as mass spectrometrometry is not sufficiently reliable, it is still not uncommon today to find such research articles published in both domestic and foreign chromatographic literatures. In this paper, the main components of nineteen essential oils have been analyzed by both capillary GC-MS and a live retention value database compiled by Guan[7], and the results were used to show that identification by a single method is not trustworthy enough, whereas the combination of them can considerably improve the reliability of identification. The advantages and limitations of the two methods were compared. The GC-MS identification is sensitive, and informative, yet it can not differentiate some isomers, which are widely met in organic analysis. On the other hand, identification by the live retention index database is simple, rapid, inexpensive and capable of differentiation between various isomers, nonetheless, the volume of the database is too small to be of practical use,especially for analyzing essential oils. It is advisable to make full use of both techniques for identification.The agreement of results between them can usually give tentative identification, which deserves further verification with authentic samples to obtain completely affirmative identification.