The invention generally relates to high-throughput label-free enzymatic bioassays using desorption electrospray ionization-mass spectrometry (DESI-MS).

The present disclosure describes an improved sample preparation technique, swab, swab holder and solvent for the removal of trace chemical materials from swabs and delivery of the trace materials into a mass spectrometer (MS) or an ion mobility spectrometer (IMS). The devices and techniques aid the delivery of the analyte into the instrument inlet and concurrently serves as an ionization source. The technique includes the steps of positioning or shaping the swab so that a pointed analyte release area is directed toward the inlet of the MS or IMS, adding a solvent to the swab and charging the swab to create an ionized analyte spray (Taylor Cone spray) into the inlet of the detection instrument. Solvent may include a chemical for depressing the ionization of residual solvent or enhancing the ionization of the desired analyte and this chemical may serve as an internal standard or benchmark.

A method of mass spectrometry is disclosed comprising focusing electromagnetic radiation into a region of a liquid sample 3 below a surface of the liquid sample so as to generate one or more bubbles 4. The one or more bubbles 4 rise to the surface of the liquid whereupon one or more droplets of liquid 6 are emitted from the surface of the liquid sample. The method further comprises directing the one or more emitted droplets 6 towards an inlet of a mass spectrometer 8.

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.

To acquire a mass spectrum for a wide mass range, a normal analysis execution controlling unit controls components to repeatedly perform measurement while changing setting m/z by a predetermined m/z at a time, and a mass spectrum summarizing processing unit summarizes data pieces each obtained by each time of measurement to generate the mass spectrum. Radio-frequency voltage applied to an ion guide and the like is changed based on the setting m/z. The radio-frequency voltage for the setting m/z is determined using a table in which a relationship between a position on an axis between upper and lower limits of the mass range and the radio-frequency voltage is substantially the same regardless of the mass range.

A system and method are provided for loading a sample into an analytical instrument using acoustic droplet ejection (“ADE”) in combination with a continuous flow sampling probe. An acoustic droplet ejector is used to eject small droplets of a fluid sample containing an analyte into the sampling tip of a continuous flow sampling probe, where the acoustically ejected droplet combines with a continuous, circulating flow stream of solvent within the flow probe. Fluid circulation within the probe transports the sample through a sample transport capillary to an outlet that directs the analyte away from the probe to an analytical instrument, e.g., a device that detects the presence, concentration quantity, and/or identity of the analyte. When the analytical instrument is a mass spectrometer or other type of device requiring the analyte to be in ionized form, the exiting droplets pass through an ionization region, e.g., an electrospray ion source, prior to entering the mass spectrometer or other analytical instrument. The method employs active flow control and enables real-time kinetic measurements.

An ambient ionisation source unit (10) is provided comprising: a housing (12) containing a first device (14) for generating analyte material from a surface of a sample to be analysed and a sampling inlet (16) for receiving analyte material liberated from the surface of the sample. The position(s) of the first device and/or sampling inlet is (are) fixed relative to the housing. Thus, the first device and the sampling inlet are integrated into a single unit that can be installed onto the front-end of an ion analysis instrument with minimal or reduced user interaction.

The invention relates to the generation of desolvated ions by electrospraying to be investigated analytically, e.g. according to the charge-related mass m/z and/or ion mobility. The cloud of highly charged. droplets drawn from the spray capillary by a high voltage is usually focused and stabilized by a beam of nebulizing gas surrounding the cloud of tiny droplets. For a fast drying of the droplets, an additional desolvation gas is usually heated to a temperature of up to several hundred degrees centigrade and blown into the cloud of droplets. The invention particularly relates to the heating of the gas which is instrumental in the generation of desolvated ions as part of the electrospraying process without any mechanical or electrical contact between the heating power supply and the heater itself, but rather by heating the heater for the gas using electromagnetic induction.

Methods and devices for pretreatment of a conducting sampling substrate which enable an electrostatic charge to be used to transfer analyte molecules onto a sampling substrate, where the analyte molecules are in powder or particulate form. In an embodiment of the present invention, the electrostatic charge can be used to transfer powder samples containing nitrogenous bases, nucleosides, food additives, and prescription drugs such as acetaminophen, oxycodone, and dextromethorphan. In an embodiment of the present invention, a powder sample is transferred to a pre-treated sampling substrate using an electrostatic charge. The spatial distribution of the powder on the original surface is retained on the pre-treated sampling substrate using the electrostatic charge transfer. The electrostatic charge transfer can be used to transfer powder samples present on a surface or in the chambers of 96, 384 and 1536 well plate formats to either pins or mesh and analyzed with ambient desorption ionization.

Disclosed herein are methods and systems for ionizing organic compounds by exposing head space vapors to corona discharge. The methods and systems are suitable for high throughput screening of samples, including biofluids. The methods and systems are suitable for rapid evaluation of chemical reactions, permitting discovery of novel organic reaction pathways.