Wouters Sam, De Vos Jelle, Dores-Sousa José Luís, Wouters Bert, Desmet Gert, Eeltink Sebastiaan
Vrije Universiteit Brussel (VUB), Department of Chemical Engineering, Brussels, Belgium.
Vrije Universiteit Brussel (VUB), Department of Chemical Engineering, Brussels, Belgium.
J Chromatogr A. 2017 Nov 10;1523:224-233. doi: 10.1016/j.chroma.2017.05.063. Epub 2017 Jun 1.
The present paper discusses practical aspects of prototyping of microfluidic chips using cyclic olefin copolymer as substrate and the application in high-performance liquid chromatography. The developed chips feature a 60mm long straight separation channel with circular cross section (500μm i.d.) that was created using a micromilling robot. To irreversibly seal the top and bottom chip substrates, a solvent-vapor-assisted bonding approach was optimized, allowing to approximate the ideal circular channel geometry. Four different approaches to establish the micro-to-macro interface were pursued. The average burst pressure of the microfluidic chips in combination with an encasing holder was established at 38MPa and the maximum burst pressure was 47MPa, which is believed to be the highest ever report for these polymer-based microfluidic chips. Porous polymer monolithic frits were synthesized in-situ via UV-initiated polymerization and their locations were spatially controlled by the application of a photomask. Next, high-pressure slurry packing was performed to introduce 3μm silica reversed-phase particles as the stationary phase in the separation channel. Finally, the application of the chip technology is demonstrated for the separation of alkyl phenones in gradient mode yielding baseline peak widths of 6s by applying a steep gradient of 1.8min at a flow rate of 10μL/min.
本文讨论了以环烯烃共聚物为基底制作微流控芯片原型的实际问题及其在高效液相色谱中的应用。所开发的芯片具有一条60毫米长的直形分离通道，其横截面为圆形（内径500微米），该通道是使用微铣机器人制作的。为了不可逆地密封芯片的顶部和底部基底，对溶剂蒸汽辅助键合方法进行了优化，从而使通道几何形状接近理想圆形。研究了四种建立微-宏界面的不同方法。微流控芯片与封装支架组合后的平均破裂压力为38兆帕，最大破裂压力为47兆帕，据信这是这些基于聚合物的微流控芯片有史以来报道的最高值。通过紫外线引发聚合原位合成了多孔聚合物整体烧结体，并通过应用光掩模对其位置进行空间控制。接下来，进行高压浆料填充，以在分离通道中引入3微米的硅胶反相颗粒作为固定相。最后，展示了该芯片技术在梯度模式下分离烷基苯酮的应用，通过在10微升/分钟的流速下施加1.8分钟的陡峭梯度，得到了6秒的基线峰宽。
