Prediction of gas chromatographic peak width in capillary columns at different temperatures, carrier gas flows, column lengths, inside diameters and carbon numbers

Width factor ( w f ), relative band broadening ( b r ) and retention factor are linearly correlated as ln  w f = ln  b r + ln  k [ Chromatographia (2002) 56 , 99–103]. The k and b r are thermodynamic and kinetic energy parameters, and expanded to cover volumetric flow of carrier gas, temperature, phase ratio (β) and carbon number ( z ). For columns of the same stationary phase and β value but of different lengths, width at base ( w b ) can be predicted with the same numerical values of the constants. The average absolute differences between predicted and experimental w b for BP‐1 columns of 30, 20 and 10 m are 1.27%, 1.21% and 1.37%, respectively. In predicting w b of n ‐alkanes eluted from columns of the same stationary phase but of different ID, only the differences of ln β are required for adjustment of one of the numerical values. The average absolute differences between w b (cal) and w b (exp) values for columns of 0.53, 0.32, 0.22 and 0.15 mm ID are 2.06, 3.67, 3.82 and 3.47%, respectively.