摘要:
An electrospray ion source apparatus comprises: a plurality of emitter capillaries, each comprising an internal bore for transporting a portion of a liquid sample from a source, an electrode portion for providing a first applied electric potential and an emitter tip for emitting a cloud of charged particles generated from the liquid sample portion; a counter electrode for providing a second applied electric potential different from the first applied electric potential; and at least one shield electrode disposed at least partially between the counter electrode and the emitter tip of at least one of the emitter capillaries for providing a third applied electric potential intermediate to the first and second applied electric potentials, wherein the at least one shield electrode is configured such that provision of the third applied electric potential to the at least one shield electrode minimizes electric field interference effects between the plurality of emitter capillaries.
摘要:
A system for preventing backflow as part of an ion source arrangement is introduced. Such a system incorporates a novel continuous flow guide within a source, such as an API ion source. In the spray direction, the cross-sectional area that defines the first portion of the internal volume initially decreases in a convergent-like manner and thereafter increases in a divergent-like manner towards the exit opening of the source housing. Such a flow guide has been designed as an integral part of an ion source housing to provide for an optimal unidirectional flow past a sampling orifice of a mass spectrometer inlet. Accordingly, the novel design of the present invention prevents recirculation and thus minimizes carryover, chemical noise, and source turbulence and as an added benefit, enables a user to easily clean such a system during maintenance.
摘要:
An ion transfer tube for a mass spectrometer comprises a core member and a first jacket tube member at least partially enclosing the core member and providing one or more channels therethrough. A method of forming an ion transfer tube, comprises: providing a first jacket tube member having a length and an internal bore, the internal bore passing along the length and defining an interior surface of circular cross section; removing at least one portion of the first jacket tube member adjacent to the interior surface so as to form at least one groove, channel, slot, recess or embayment of or in the interior surface; and providing a core member within the bore of the jacket tube member such that remnant portions of the interior surface of circular cross section mate against portions of an exterior surface of the core member.
摘要:
An ion transfer tube for a mass spectrometer comprises a tube member having an inlet end and an outlet end; and at least one bore extending through the tube member from the inlet end to the outlet end, the at least one bore having a non-circular cross section. A method of forming an ion transfer tube comprises the steps of providing a tube member having a length and an internal bore, the internal bore having a wall of circular cross section; and etching or eroding portions of the tube member adjacent to the wall so as to form an enlarged bore having a non-circular cross section.
摘要:
An ion transport apparatus for a mass- or ion-mobility-spectrometer comprises: (a) a plurality of strip electrodes in a series on a fiat substrate; (b) an ion outlet aperture in the substrate disposed adjacent to a first one of the plurality of strip electrodes; (c) a cage electrode at least partially enclosing the plurality of strip electrodes and the ion outlet aperture; (d) a radio frequency (RF) voltage generator operable to supply an RF phase difference between each pair of adjacent electrodes; and (e) at least one DC voltage source operable to supply first and second DC voltages to the cage electrode and an extraction electrode and to supply respective DC bias voltages to each of the plurality of electrodes, wherein electrode strip widths of a series of the plurality of electrodes progressively increase away from the first one of the plurality of electrodes.
摘要:
An electrospray ion source for a mass spectrometer for generating ions of an analyte from a sample comprising the analyte dissolved in a liquid solvent comprises: an electrode receiving the sample and comprising at least a first plurality of protrusions protruding from a base, each protrusion of the at least a first plurality of protrusions having a respective tip; and a voltage source, wherein, in operation of the electrospray ion source, the sample is caused to move, in the presence of a gas or air, from the base to each protrusion tip along a respective protrusion exterior so as to form a respective stream of charged particles emitted towards an ion inlet aperture of the mass spectrometer under application of voltage applied to the electrode from the voltage source.
摘要:
An ion transfer tube having an ion inlet and an ion outlet comprises: a first tube member comprising an electrically resistive material and having a first end comprising the ion inlet and a second end; a first electrode electrically coupled to the first tube member; a second tube member having a first end in leak-tight contact with the second end of the first tube member and a second end comprising the ion outlet; a second electrode electrically coupled to either the first tube member or the second tube member; and a heater thermally coupled to at least one of the tube members, wherein, in operation, an electrical potential difference applied between the electrodes produces an electric field within the first tube member that urges charged particles through the first tube member into the second tube member and the heater supplies heat to the charged particles within the ion transfer tube.
摘要:
An apparatus and method for introducing ions into a vacuum chamber of a mass spectrometer includes producing ions in an ionization chamber of an ion source. The ions are sampled into an intermediate pressure chamber via a first ion transfer tube. In particular, the pressure within the intermediate pressure chamber is maintained at a value that exceeds a maximum pressure for being sampled into the vacuum chamber of the mass spectrometer. Some of the ions are sampled from the intermediate pressure chamber via at least a second ion transfer tube, the at least a second ion transfer tube having an outlet end that is in communication with a low-pressure chamber. In particular, the pressure within the low-pressure chamber is maintained at a value that is less than a maximum pressure for being sampled into the vacuum chamber of the mass spectrometer. Some of the ions are sampled from the low-pressure chamber into the vacuum chamber of the mass spectrometer.
摘要:
An electrospray ion source comprises a source of analyte-bearing liquid; a source of sheath gas; a plurality of liquid conduits, each configured so as to receive a portion of the analyte-bearing liquid; at least one electrode associated with the plurality of liquid conduits for producing electrospray emission of charged droplets from an outlet of each of the liquid conduits; a power supply electrically coupled to the at least one electrode for maintaining the at least one electrodes at an electrical potential; and either one or a plurality of sheath gas conduits, each sheath gas conduit comprising an inlet configured to receive sheath gas and an outlet configured to emit a sheath gas flow that circumferentially surrounds, in at least two dimensions, a portion of the emitted charged droplets.