Similar to the binary mixtures, it is possible to relate the response factor of one isomer 𝑘𝑘 𝑖𝑖 to a 'reference' isomer 𝑘𝑘 0 : p i0 = k i /k 0 . The reference isomer can be any one of the isomers in the mixture. To obtain the relative response factor values we need to construct the calibration curves for binary mixtures, containing one of the presented isomers "i" and the selected reference isomer "0". The IM spectra for the binary mixtures and the multicomponent mixture should be measured in a single set of experiments. Thus, for multicomponent mixtures the relative response factors 𝑝𝑝 𝑖𝑖0 cannot be derived from the curves shown in Figure unless the binary calibration curve is generated at the same time with the same external conditions. Once the relative response factor 𝑝𝑝 𝑖𝑖0 is obtained, the molar fraction can be calculated. This can be achieved by rewriting Eq. 2 as Eq. 3 since ∑ 𝜒𝜒 𝑖𝑖 = 1 𝑛𝑛 𝑖𝑖=1