氯仿“A”分析新方法及C_7以上正构烷烃地化指标

提出一种解决轻烃损失的测定氯仿“Ａ”的新方法。采用正己烷冷抽提，气相色谱外标计量抽提物（Ａ１），残样再用氯仿进行二次冷抽提，得到氯仿抽提物（Ａ２）。（Ａ１＋Ａ２）即为样品中包括轻烃组分的氯仿“Ａ”量。讨论了上述冷抽提物中正构烷烃地化指标的计算方法。将实际样品的测定结果与常规方法作了对比，表明轻烃组分对某些地化指标有较大影响。

NEW METHOD FOR DETERMINATION OF CHLOROFORM“A”AND THE GEOCHEMISTRY INDICATOR OF>nC_7NORMAL PARAFFIN HYDROCARBONS

A new method has been developed for the determination of chloroform“A”in rocks,by which the loss of light hydrocarbons can be avoided.The rock sample is extracted by nheptane at room temperature and the extractive solution is analysed by GC and the quantity of the extractive is determined, which is A_1.The remains are then extracted with chloroform,the quantity of the extractum is A2.A1+ A2 is equal to the chloroform“A”of the rock sample,which contains the quantity of light components.The calculation method of geochemistry indcators of normal paraffin hydrocarbons has been discussed and the results of the method is compared with those by normal method,which indicates that the light components could affect strongly some geochemistry indicators of sample.