本文描述了一个描述水样传质的模型。基于模型预测，评估了SPME-GC/MS在配水系统水质在线监测和控制中的适用性。主要问题是收集有关流体力学、热力学和动力学影响的一些信息，以便将SPME的适用性扩展到管内取样。该模型基于物理传质方程，描述了分析物从本体溶液到纤维表面的转移、分析物在纤维聚合物涂层中的扩散以及分析物在纤维涂层和水相之间的平衡因子K。纤维上分析物的最终浓度c2f被描述为雷诺数Re（水动力条件）、扩散系数d1（水中分析物）和d2（纤维涂层中分析物）、K、萃取时间t、分析物在本体溶液c1中的浓度和纤维几何形状的函数。 为了验证理论预测并确定萃取过程的速率决定步骤，在闭环管道试验台中，在受控流体动力学条件下进行了实验。计算表明，只有平衡因子相似的物质才能同时测定，以获得大小相似的检测器信号。

This paper describes a model for the description of the mass transfer from the aqueous sample. Based on the model predictions the applicability of SPME-GC/MS for on-line monitoring and control of water quality in the distribution system is evaluated. The main issue is to gather some information on the influence of hydrodynamics, thermodynamics and kinetics in order to extend SPME's applicability to on-pipe sampling. The model is based on physical mass transfer equations describing the transfer of analytes from the bulk solution to the surface of the fiber, the diffusion of the analyte in the polymer coating of the fiber and the equilibrium factor K of the analyte between the fiber coating and the water phase. The final concentration c2f of the analyte on the fiber is described as a function of the Reynolds number Re (hydrodynamic conditions), the diffusion coefficients d1 (analyte in water) and d2 (analyte in fiber coating), K, the extraction time t, the concentration of the analyte in the bulk solution c1 and the fiber geometry. The experiments were carried out under controlled hydrodynamic conditions in a closed-loop pipe rig in order to verify the theoretical predictions and to determine the rate determining step of the extraction process. The calculations suggest that only substances with similar equilibrium factors should be determined at the same time in order to obtain detector signals of similar size.