计算机模拟咖啡因在反相液相色谱固定相上的保留行为

Computation of the retention behavior of caffeine in reversed-phase liquid chro-matography

运用前沿分析法测定了咖啡因在反相液相色谱固定相上的吸附等温线,并对单位点和多位点Langmuir吸附等温式式运用Origin软件进行了非线性拟合。通过平衡扩散模型运用数值方法从理论上计算出可能的洗脱色谱峰,并与实验值进行了比较。结果表明多位点吸附模型更符合实际情况。从理论上探讨了固定相上残余硅醇基等对溶质色谱峰可能造成的影响。

The adsorption of caffeine onto C18 bonded silica was measured by staircase frontal analysis, isotherm data were fitted to Langmuir isotherms that assumed one or two types of adsorption site on the stationary phase. With equilibrium-disperse model the elution peak curves were calculated and compared to experimental ones. Results showed that the theoretical curves calculated by using the model assuming two types of adsorption site on the stationary phase were closer to experimental data.