Comprehensive two-dimensional gas chromatography and chemometrics for the high-speed quantitative analysis of aromatic isomers in a jet fuel using the standard addition method and an objective retention time alignment algorithm

A high-speed quantitative analysis of aromatic isomers in a jet fuel sample is performed using comprehensive two-dimensional gas chromatography (GC x GC) and chemometrics. A GC x GC separation time of 2.8 min is achieved for three aromatic isomers in jet fuel, which is 5 times faster than a referenc e method in which a single-column separation resolves two of the three isom ers of interest, The high-speed GC x GC separation is more than 10 times fa ster than a recent GC x GC separation that fully resolves the three compone nts of interest in gasoline. The high-speed GC x GC analysis of jet fuel is accomplished through short GC columns, high gas velocities, and partial ch romatographic peak resolution followed by chemometric resolution of overlap ped peaks, The standard addition method and an objective retention time ali gnment algorithm are used to correct for retention time variations prior to the chemometric data analysis. The standard addition method corrects for c hemical matrix effects that cause analytes in complex samples to have peak shapes, widths, and retention times that differ considerably from those of calibration standards in pure solvents. The retention time alignment algori thm corrects for the relatively small retention time variations caused by f luctuating instrumental parameters such as now rate and temperature. The us e of data point interpolation in the retention time alignment algorithm res ults in a more accurate retention time correction then previously achieved. The generalized rank annihilation method (GRAM) is the chemometric techniq ue used to resolve the overlapped GC x GC peaks. The correction of retentio n time variations allows for successful GRAM;I signal deconvolution, Using the retention time alignment algorithm, GRAM quantification accuracy and pr ecision are improved by a factor of 4. The methodology used in this paper s hould be applicable to other comprehensive separation methods, such as two- dimensional liquid chromatography, Liquid chromatography coupled with capil lary electro-phoresis, and Liquid chromatography coupled with gas chromatog raphy.