Method and apparatus for chromatography-high field asymmetric waveform ion mobility spectrometry

A method for analysis of compounds in a chromatographic eluent, including the steps of:

• providing a high field asymmetric ion mobility filter system with an internal flow path, enabling attachment of the output of a chromatograph system to said flow path, said flow path opening into the input part of a said high field asymmetric ion mobility filter system, said system further including, an ion filter part for filtering ions, and an output part, said flow path connecting said parts,
• supporting said parts with a support structure, said ion filter part including at least a pair of filter electrodes, said filter electrodes being on said support structure,
• providing said support structure with an electrode support in said ion filter part adjacent to said filter electrodes for support of said filter electrodes in said ion filter part, said filter electrodes being separated and forming an analytical gap in said ion filter part, said flow path extending through said analytical gap,
• defining said analytical gap as well as the sides of said flow path in said ion filter part by cooperation of said support structure, said filter electrode support and said filter electrodes,
• providing a compensated asymmetric filter field within said analytical gap between said electrodes,
• separating at least one analyte chromatographically from a chemical mixture and eluting said separated analyte into said flow path, said analyte forming a chromatographic peak that is associated with a chromatographic residence time, said peak having a peak duration of some time period,
• providing a flow of ions to said ion filter part in said flow path within said time period, including the step of ionizing at least a portion of said separated at least one analyte and forming at least one ion species, further including flowing said at least one ion species into said flow of ions within said time period,
• providing said compensated asymmetric filter field transverse to said flow path in said ion filter part within said time period,
• filtering said flow of ions within said time period and selecting said at least one ion species out of said flow of ions, said selection being made according to aspects of ion mobility characteristics of said at least one ion species in said transverse field within said time period, and
• passing said selected at least one ion species to said output part within said time period for characterization of said at least one analyte according to mobility characteristics of said selected at least one ion species in said transverse field within said time period.

Apparatus for fast characterization of a chromatographic sample, comprising:

• an input part, an ion filter part for filtering ions in an electric filter field, an output part, and a flow path connecting said parts,
• said parts being supported by a support structure defined by cooperating substrates,
• said ion filter part including at least a pair of plate-type filter electrodes on said substrates in said ion filter part and forming conductive electrode surfaces, said substrates forming other supporting surfaces in said ion filter part that support said electrodes in said ion filter part, said electrodes separated from each other and defining an analytical gap in said ion filter part, said filter field being generated across said flow path in said gap,
• said filter electrodes providing a compensated asymmetric RF filter field within said gap, wherein surfaces of said gap in said ion filter part are cooperatively defined by said electrodes and said support structure,
• said input part for receiving a chromatographic eluent, said eluent including at least one analyte, said input part for delivering a flow of ions to said flow path, said flow of ions including at least one ion species associated with said analyte, said ion filter part filtering said flow of ions in said compensated asymmetric RF filter field in said gap,
• wherein said analyte is represented by a chromatographic peak flowing at a selected flow rate, said peak having a peak duration in said ion filter part, and
• wherein said ion filter part passes said selected at least one ion species to said output part within said peak duration for characterizing said at least one ion species within said peak duration according to aspects of ion mobility in the filter field.