Application Of Nonlinear Plate Theory In Predicting Retention Times Of Gas Chromatography With Curate Capillary Column

At present, the research on the prediction of retention time in gas chromatography can be mainly classified into three aspects, including the prediction model on the retention index, on the structure–retention relationships and on the chromatographic retention values equation. All of these studies were under the condition of using the same length capillary gas chromatographic column. When the length of the column became significantly shorter, the retention time values of the sample will also obviously decrease compared with the values in long column under the same separation condition. In order to find the best programmed-temperature conditions, people should re-measure retention times of samples at different constant temperatures, and re-predict retention times of samples in programmed-temperature condition with new data. However, it is a time-consuming work, and is difficult to be applied in routine analysis; In this paper, we studied intrinsic thermodynamics relationship between the long and short column on the prediction of retention time based on the nonlinear plate theory; and predicted retention times of the samples in the curate column with the constant temperature data of components in the original length column under different programmed-temperature conditions; we also discussed the relationships between the column length, flow rate and temperature. On the other hand, this study was also used to predict retention times of samples in the curate column under programmed-temperature and -flow rate condition with the above mathematical model. From the results of prediction on retention times under the programmed–temperature and–flow condition, we known that the non-linear plate theory can be used to predict retention times in any different length chromatographic separation column and separation modes, and the method is simple, vivid, easy to be understood, and is valuable.