A preferred method for identifying analytes of samples by utilizing chemometric analysis for interpreting chromatographic data obtained under locked conditions includes the steps of: (1) providing a locking GC system which includes a column operated at a column head pressure; (2) adjusting the column head pressure of the locking GC system so that a column void time of the column in the locking GC system, when a known analyte is eluted therethrough, is matched with the column void time of the column in a reference GC system, when the known analyte is eluted therethrough; (3) analyzing the sample with the locking GC system so that chromatographic data corresponding to the sample is compiled, and; (4) performing chemometric analysis on the chromatographic data.