Prediction Of Retention Times In Temperature Programmed Tandem-column GC

In this study, we developed a simple and effective method for fast and accurateprediction of retention times in temperature programmed tandem-column GC basedon isothermal data of individual columns and calibrated hold-up times of thetandem-column GC. Isothermal data of two individual columns with differentpolarities were used to determine retention equations in this method. The introductionof calibrated hold-up time of front and back columns not only simplified theprediction process of retention time but also avoided the tedious measurements ofcolumn parameters in tandem-column TPGC. The calibrated hold-up times can beobtained by two separate approaches.In order to test if this method is valid, a prediction based on literature data wascompleted. The predicted retention times were in excellent agreement withexperimentally determined values. Compared to the model described in the literature,this method is more simple and accurate.In addition, we used experiments to illustrate the prediction process of retentiontimes in tandem-column TPGC. Calibrated hold-up time was obtained by predictingtwo calibrating compounds in tandem-column TPGC single-ramping runs to test ifthey are eligible to predict retention times in such system. When all the relative errorbetween the predicted retention times and experimental values is within±4.00%, thecalibrated hold-up times of front and back columns at each constant temperature wereobtained, respectively.Using retention equations and relationships between calibrated hold-up times andtemperatures, the retention times of analytes were predicted on single-ramping andmulti-ramping runs in tandem-column TPGC. A good agreement between thepredicted and experimental values was obtained: the relative error was less than±6.00%for every tested analyte on tandem-column TPGC, and the average absoluteerror of AP1and AP2for single-ramping and multi-ramping was below2.50%and2.60%, respectively. Our method remains robust and efficient even when thedimensions of the columns in the tandem-column TPGC are changeable.