Prediction of gas chromatographic peak width in capillary columns at different temperatures, carrier gas flows, column lengths, inside diameters and carbon numbers.
Width factor (wf), relative band broadening (br) and retention factor are linearly correlated as ln wf = Inbr + ln k [Chromatographia (2002) 56, 99 -103]. The k and br are thermodynamic and kinetic energy parameters, and expanded to cover volumetric flow of carrier gas, temperature, phase ratio (beta) and carbon number (z). For columns of the same stationary phase and beta value but of different lengths, width at base (wb) can be predicted with the same numerical values of the constants. The average absolute differences between predicted and experimental wb for BP-1 columns of 30, 20 and 10 m are 1.27%, 1.21% and 1.37%, respectively. In predicting Wb of n-alkanes eluted from columns of the same stationary phase but of different ID, only the differences of ln beta are required for adjustment of one of the numerical values. The average absolute differences between Wb(cal) and Wb(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.
Biochemical Technology Division, School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok, Thailand. kanit.kri@kmutt.ac.th
Kanit
K
Krisnangkura
Varaporn
V
Pongtonkulpanich
D002849:Chromatography, Gas / Q000295:instrumentation / Q000379:methods*; D008956:Models, Chemical; D013696:Temperature; D013816:Thermodynamics