两种轻烃分析方法(“PTV切割反吹”和“顶空”)的对比研究

Contrastive Study of Two Methods("Programmed Temperature Vaporization with Back Flushing" and "Head Space")for Light Hydrocarbon Analysis

建立了“程序升温蒸发进样器 (PTV)切割反吹”和“顶空”两种有关原油中轻烃的分析方法 ,色谱柱的使用寿命长、分析周期短 ,原油中 <C9的较轻组分的分离度能达到美国材料试验学会 (ASTM)D5 13 4 98所要求的标准 ,并有良好的重复性。此外 ,还报道了采自我国 6个油区的 10个油样用两种分析方法所得 19个地化参数的相对误差范围约为± ( 1%～ 2 5 % ) ,并对引起误差的原因进行了探讨。指出用这两种方法所获得的数据是不能合在一起作地化研究的 ,将原油直接注入汽化室所得的分析数据较可靠 。

Light hydrocarbon analytical method of 'PTV with Back Flushing' presented here is characterized as follows: a) with 'PTV' inlets temperature programmed; b) with gas line system of 'Back Flushing'; c) with direct injection of oil samples After oil sample injection, 'Back Flushing' is on when light hydrocarbon components enter into analytical chromatographic column At the same time, the temperature of inlet increases The high temperature and 'Back Flushing' blow the heavy components in the oil samples out of the analytical system Besides, the analytical method of 'Head Space' was established Both 'PTV with Back Flushing' and 'Head Space' have the advantages of long column life and short analysis time The resolution for lighter components <C 9 meets the criterion of ASTM D5134 98, with the good repeatability Ten oil samples from 6 oil areas were analysed by using the two methods The relative deviations between the two analytical results represented by 19 geochemistry parameters were about ±(1% 25%) The reasons for the deviation are discussed It is pointed out that in geochemistry study it is not acceptable to combine the data obtained from two analytical methods The analytical results obtained by injecting crude oil directly into injector are more reliable The results obtained in 'Head Space'analytical method should be calibrated when used in geochemistry study