An open tubular (OT) sample preparation/separation platform was developed. A multi-channel polymer layer open tubular (mPLOT) solid phase extraction (SPE) column was prepared by wall-coating the 126 channels (8 μm inner diameter (ID) each) of a crystal fiber capillary with an organic polymer, namely poly(styrene-co-octadecene-co-divinylbenzene) (PS-OD-DVB). The mPLOT SPE was coupled on-line with a 10 μm × 2 m poly(styrene-co-divinylbenzene) (PS-DVB) OT liquid chromatography column with nanospray mass spectrometry (OTLC–MS). Compared to using monolithic/particle-packed SPEs, mPLOT-SPE-OTLC allowed both fast loading and sufficient refocusing on the OT analytical column of small model compounds (sulfonamides ≈ 300 Da). Using automatic filtration/filter back-flushing (AFFL) plumbing, the mPLOT SPE column gave a constant and low back-pressure ≈35 bar at 0.5 μL/min. Surprisingly large sample volumes (10 μL) were possible to be injected using a 12 cm mPLOT.

开发了开放式管状（OT）样品制备/分离平台。通过用有机聚合物即聚（苯乙烯-十八碳烯-二乙烯基苯）（PS-OD-DVB）。mPLOT SPE与10μm×2 m的聚（苯乙烯-共二乙烯基苯）（PS-DVB）OT液相色谱柱通过纳米喷雾质谱（OTLC-MS）在线耦合。与使用整体/颗粒填充的SPE相比，mPLOT-SPE-OTLC可以快速加载并在小模型化合物（磺酰胺≈300 Da）的OT分析柱上进行充分的聚焦。使用自动过滤/过滤器反冲洗（AFFL）管道，mPLOT SPE色谱柱在0.5μL/ min时提供恒定且低的背压≈35 bar。出乎意料的是，使用12 cm mPLOT可以进样大体积样品（10μL）。