São Carlos Institute of Chemistry, University of São Paulo, São Carlos 13566-590, Brazil.
Molecules. 2023 Jun 29;28(13):5103. doi: 10.3390/molecules28135103.
This work presents a study on the application of wall open tubular column (WCOT) in liquid chromatography coupled with tandem mass spectrometry. Each process step reports the column preparation method in detail, subdivided into column pretreatment, silanization, stationary phase coating, and immobilization. Then, an evaluation of the parameters that can affect the efficiency of these columns was made. Atrazine, clomazone, and metolachlor were used as probes during this step. Factors such as stationary phase composition, length, internal diameter, stationary phase mass employed, and injection volume were investigated. In addition, with the help of Knox and Poppe graphs, the columns' performance was evaluated to determine the optimal flow rate and the speed-efficiency relationship, respectively. Based on the results, the best configurations for the WCOT column application to the LC system were defined: length-8 m; inner diameter-25 μm; mass of OV-210-2.5% /; and, injection volume-100 nL. Finally, the optimized WCOT column developed in this work was coupled with a commercially-packed trapping column in the nano liquid chromatography system (nanoLC). In this configuration, more significant results were obtained regarding separation resolution, with Rs = 5.9 achieved for the most retained pair of analytes (clomazone and metolachlor).
本工作研究了壁开口管柱（WCOT）在液相色谱-串联质谱中的应用。每个过程步骤都详细报告了柱的制备方法，分为柱预处理、硅烷化、固定相涂层和固定化。然后，对可能影响这些柱效率的参数进行了评估。在此步骤中，莠去津、氯甲草和甲草胺被用作探针。研究了固定相组成、长度、内径、固定相质量、进样量等因素。此外，借助 Knox 和 Poppe 图谱，分别评估了柱的性能，以确定最佳流速和速度-效率关系。基于结果，确定了 WCOT 柱在 LC 系统中应用的最佳配置：长度-8 m；内径-25 μm；OV-210 质量分数-2.5%/；进样量-100 nL。最后，在纳米液相色谱系统（nanoLC）中，将本工作中开发的优化 WCOT 柱与市售捕集柱相耦合。在这种配置下，在分离分辨率方面获得了更显著的结果，最保留的一对分析物（氯甲草和甲草胺）的 Rs 值达到了 5.9。
