Gas chromatography (GC) is a frequently applied separation technique. Nevertheless, a suitable operational setup for reaching separation may require extensive time and resources. Mathematical models have been used to predict chromatographic parameters and to propose the analysis conditions; however, the use of empirical correlations has limited application and may be inaccurate. This work proposed a precise physical-based mathematical model using mechanistic equations to describe GC under constant pressure and constant flow, aiming to predict holdup time and the full separation process in a CFD software. A bidimensional model was validated by the description of the mobile phase flow and compounds elution, allowing to predict the chromatographic parameters in both GC operating modes. The observed errors were less than 5% for all predicted parametric values, which is around the input parameter uncertainty. The 2D approach allowed a relatively quick computational time to describe with high accuracy the evaluated parameters, concentration profile, and an operational setup for separating the compounds.

气相色谱（GC）是一种经常使用的分离技术。然而，用于实现分离的合适的操作设置可能需要大量的时间和资源。数学模型已用于预测色谱参数并提出分析条件。然而，经验相关的使用限制了应用并且可能是不准确的。这项工作提出了一个精确的基于物理的数学模型，该模型使用力学方程式描述了恒压恒流下的气相色谱，目的是在CFD软件中预测滞留时间和全分离过程。通过描述流动相流动和化合物洗脱，验证了二维模型，从而可以预测两种GC操作模式下的色谱参数。对于所有预测的参数值，观察到的误差均小于5％，该误差在输入参数不确定性附近。2D方法允许相对快速的计算时间来高精度地描述评估的参数，浓度曲线和用于分离化合物的操作设置。