A novel concept for ion spatial peak compression is described, and discussed primarily in the context of ion mobility spectrometry (IMS). Using theoretical and numerical methods, the effects of using non-constant (e.g., linearly varying) electric fields on ion distributions (e.g., an ion mobility peak) is evaluated both in the physical and temporal domains. The application of a linearly decreasing electric field in conjunction with conventional drift field arrangements is shown to lead to a reduction in IMS physical peak width. When multiple ion packets (i.e., peaks) in a selected mobility window are simultaneously subjected to such fields, there is ion packet compression (i.e., a reduction in peak widths for all species). This peak compression occurs with only a modest reduction of resolution, which can be quickly recovered as ions drift in a constant field after the compression event. Compression also yields a significant increase in peak intensities. Ion mobility peak compression can be particularly useful for mitigating diffusion-driven peak broadening over very long path length separations (e.g., in cyclic multi-pass arrangements), and for achieving higher S/N and IMS resolution over a selected mobility range.
Abstract Peak compression and deformation effects were studied in a reversed phase ion-pair adsorption chromatographic system, comprising silanized (C18) silica as solid phase and an acidic mobile phase. An indirect detection technique was used, protriptyline (a secondary hydrophobic amine) being the probe, and substituted benzamides the analytes. 相似文献
