The previously proposed approach for controlling the inertness of gas chromatographic (GC) systems was based on the determination of peak area ratios for polar and non-polar constituents of test-solutions ( S rel = S polar/ S non-polar) for the series of samples obtained by the consequent dilutions (for the 10-times dilutions the number of samples was five). This approach was modified with the purpose of increasing the reliability of evaluating the minimal quantities of analytes ( m lim), for which one can neglect the insufficient inertness of GC systems. In addition to that, the simplification of experimental operations and minimizing the number of parallel determinations as well as more rational algorithm of data processing was achieved. The essence of the modified approach was the approximation of S rel = f (p m ) data sets with the 3rd degree polynomials, following by comparing these data with the averaged S rel (with standard deviations) values for the most reproducible S rel values of three test-solutions with the highest concentrations of test-compounds. It was shown that the limits of the inertness for the WCOT-column (with the standard non-polar polydimethylsiloxane stationary phase) were from the fractions of nanogram to several nanograms of polar analytes in the chromatographic zone. The results for the test-samples contained some polar constituents (e.g., benzyl alcohol) which lead to suggesting that the integral manifestations of the insufficient inertness could be caused not only by the influence of chromatographic systems, but also by the sorption of polar analytes on the surfaces of vials used for the dilution of test-samples. The differences in m lim values for the same polar components at the same analytical conditions, when the dilutions were carried out in the glass or polypropylene vials, were revealed.