A first spray unit (201) sprays a first sample into a first space (20) while charging the first sample. A second spray unit (202) sprays a second sample into the first space (20) or a second space (21) communicating with the first space (20) while charging the second sample. A determination unit (62) determines whether or not the second sample is sprayed from the second spray unit (202). A gas supply unit (74) supplies gas into the first space (20). A control unit (63) controls supply of the gas from the gas supply unit (74). In a case where the determination unit (62) determines that the second sample is sprayed from the second spray unit (202), the control unit (63) starts the supply of the gas from the gas supply unit (74) into the first space (20).

A single type quadrupole mass spectrometer equipped with an ion source by the ESI method, which is a small device including a vacuum pump having a relatively small evacuation speed. The internal diameter of a desolvation tube for introducing ions from an ionization chamber into a first intermediate vacuum chamber is set to 0.4 mm φ, which is large for a small mass spectrometer. The evacuation speed of a rotary pump is determined so that the product of the cross-sectional opening area of the desolvation tube and the pressure in the first intermediate vacuum chamber falls within a range of 15 to 40 mm.sup.2.Math.Pa. This can ensure high detection sensitivity and reduce clogging of the desolvation tube due to droplets. Since the pressure in the first intermediate vacuum chamber does not need to be increased more than necessary, a small rotary pump having a small evacuation speed can be used.

In one aspect, an ion source for use in a mass spectrometry system is disclosed, which comprises a housing, a first and a second ion probe coupled to said housing, and a first and a second emitter configured for coupling, respectively, to said first and second ion probes. The first ion probe is configured for receiving a sample at a flow rate in nanoflow regime and the second ion probe is configured for receiving a sample at a flow rate above the nanoflow regime. Each of the ion probes includes a discharge end (herein also referred to as the discharge tip) for ionizing at least one constituent of the received sample. In some embodiment, each ion probe receives the sample from a liquid chromatography (LC) column. Further, the ion probes can be interchangeably disposed within the housing.

The invention generally relates to systems and methods for on-line reaction monitoring. In certain embodiments, the invention provides systems that include a reaction vessel having an outlet, a quantitation unit coupled to the outlet and configured to introduce internal standard and solvent into reaction solution flowed from the reaction vessel, one or more ion generating devices that receive flow from the quantitation unit, and a mass spectrometer. In certain embodiments, the invention provides systems for multiple reaction monitoring that include a plurality of reaction vessels, a plurality of ion generating devices, a plurality of channels, each channel coupling a reaction vessel to an ion generating device, an actuator coupled to the plurality of ion generating devices to thereby allow movement of the plurality of ion generating devices, and a mass spectrometer.

Provided is an ionization method for ionizing a sample 21 adhered to a tip of a probe 11 that is electrically conductive, by applying an ionization voltage to the probe 11 to electrically charge the sample 21. The ionization method includes: subjecting the probe 11 to treatment to make a surface of the probe 11 homogenous; causing adhesion of the sample 21 to the tip of the probe 11; and ionizing the sample 21 by applying the ionization voltage to the probe 11 to electrically charge the sample 21. The treatment for making the surface of the probe 11 homogenous can be implemented by, for example, causing corona discharge at the probe 11.

Provided herein is a method for analyzing a molecular interaction. In some embodiments the method may comprise: capturing an analyte on a probe that comprises a binding agent, inserting the probe into the interior capillary of an electrospray emitter, releasing the analyte from the probe while it is in the emitter using an elution liquid, nebulizing the analyte by electrospray; and analyzing the nebulized analyte by mass spectrometry.

Methods and systems for multi-beam, parallel-beam, deterministic, or super mass spectrometry that include an ion source that produces ions, and two or more ion trapping devices or mass spectrometers, each having an independent sampling inlet. The two or more ion trapping devices or mass spectrometers receive the ions from the ion source via the sampling inlet of each of the ion trapping devices or mass spectrometers such that each sampling inlet provides an ion beam to each corresponding ion trapping device or mass spectrometer.

Exemplary embodiments may deploy a valve that introduces a sample of a calibrant coaxially with flow exiting a source of a mobile phase flow, such as a liquid chromatography (LC) column, on a path to an ion source for the mass spectrometer (MS). The valve may be positioned remotely on a branch that has a junction with the path leading form the source of the mobile phase flow to the ion source. Alternatively, the valve may be positioned in line on the flow path from the source of the mobile phase flow to the ion source of the MS. A novel five port valve design may be employed. With this valve design, a first position of the valve allows a sample loop for the calibrant to be filled. In a second position, the calibrant is added coaxially to the flow from the source of the mobile phase to the MS. In a third position of the valve, diversion of or infusion to a post-source flow is enabled.

Systems and methods for atmospheric pressure chemical ionization are provided herein. In various aspects, the APCI apparatus, systems, and methods can provide an asymmetric sample spray into a vaporization chamber asymmetrically (e.g., off axis from the longitudinal axis of the vaporization chamber) so as to increase the interaction of the molecules in the sample spray with the vaporization chamber's sidewalls (and expose more of the molecules to the heat generated thereby), which can thereby result in improved consistency and/or efficiency of ion formation, and/or increased sensitivity relative to conventional APCI techniques.

Mass spectrometer based analytical systems and methods in which a feedback control system can be utilized to control the flow of liquid within a sampling probe to adjust and/or maintain the surface profile (e.g., shape) of the liquid-air interface within an open sampling port of the sampling probe. The feedback control systems can automatically monitor and/or detect the surface profile of the liquid-air interface and adjust the flow rate of the sampling liquid to ensure that experimental conditions remain consistent at the time of sample introduction during serial samplings. These can provide stable and reproducible analyte flows of consistent dilution to the ion source, increasing reproducibility and/or accuracy of data generated by MS analysis. Can be used with a change in the desired set point according to the particular experimental workflow (e.g., automated adjustment between an interface corresponding to a sampling set point and a cleaning set point).