直链单烯烃保留指数与分子结构关系的研究

The Study of Relation of the Retention Indices of n Alkenes with Their Molecular Structure

根据同系直链单烯烃保留指数与同碳数正构烷烃保留指数差值与分子碳数间关系曲线拟合，提出预测同系直链单烯烃保留指数的准确公式。在ＳＱ，ＰＦＥ，ＰＥＧ－４０００上，利用所提出的公式对检验集中化合物保留指数预测值与实测值差的标准偏差在±０．９ｉ．ｕ．～±１．５ｉ．ｕ．之间。并且研究发现，同碳数、同几何构型直链单烯烃各位置异构体分子中双键位置与化合物保留指数具有指数关系。首次提出依据分子中双键位置预测其保留指数的准确公式。公式适合各种不同极性固定相。Ｃ１５～Ｃ１８直链单烯烃各位置异构体在ＨＣ，ＡＬ和ＣＷ－２０Ｍ固定相上预测值与实测差值的标准偏差在±０．９ｉ．ｕ．～±１．２ｉ．ｕ．之间。解决了从低碳数直链单烯烃保留指数预测高碳数直链单烯烃各异构体保留指数及其出峰顺序问题。

When the difference values between the retention indices of homologous series of n alkenes and that of n alkanes with the same carbon number were plotted with the number of carbon atoms in the molecule, it can be seen that the curve is nearly an exponential curve. We proposed an accurate formula to predict the retention indices of homologous series of n alkenes. The retention indices of a total of 99 C12 C16 n alkenes on capillary columns with stationary phase of Squalane, PFE and PEG 4000 were calculated. The standard deviations of the retention indices were ±09 ±15 index units. When the retention indices of n alkenes with the same carbon numbers and the same geometric structure were plotted with the positions of the double bond in the molecule, it can be seen that the curve is also approximately an exponential curve. Therefore, we put forward an exact formula to predict the retention indices of the n alkenes. The universality of the formula is demonstrated by predicting a total of 178 retention indices of C15 C18 n alkenes on capillary columns with stationary phases of C87 hydrocarbon, Apiezonl L, CW 20M. The standard deviations of retention indices were ±09 ±12 index units.