Particulate capillary precolumns with double-end polymer monolithic frits for on-line peptide trapping and preconcentration

In this work, a novel kind of particulate capillary precolumns with double-end polymer monolithic frits has been developed. Firstly, the polymer monolithic frit at one end was prepared via photo-initiated polymerization of a mixture of lauryl methacrylate and ethyleneglycol dimethacrylate with 1-propanol and 1,4-butanediol as porogens and 2,2-dimethoxy-2-phenylacetophenone as a photo-initiator in UV transparent coating capillary (100 μm i.d.). Subsequently, C18 particles (5 μm, 100 Å) were packed into the capillary, and sealed with the polymer monolithic frit at another end. To prevent the reaction of monomers and C18 particles, the packed C18 particles were masked during UV exposure. The loading capacity of such a precolumn was determined to be about 9 μg by frontal analysis with a synthetic peptide APGDRIYVHPF as a model sample. Furthermore, two parallel precolumns were incorporated into a two-dimensional nano-liquid chromatography (2D nano-LC) system with dual capillary trap columns for peptide trapping and concentration. Compared to 2D nano-LC system with a single trap column, such two dimensional separations could be operated simultaneously to improve the analysis throughput. All these results demonstrated that such capillary precolumns with double frits would be promising for high-throughput proteome analysis.

Graphical abstract2D-nano-SCX-dual capillary trap columns-RPLC–MS/MS platform constructed with double-end polymer monolithic frits capillary precolumns.Figure optionsDownload full-size imageDownload as PowerPoint slide