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.

An interface for receiving ions in a carrier gas from an atmospheric pressure ion source at a spectrometer that is configured to analyse the received ions at a lower pressure includes an interface vacuum chamber having a downstream aperture; a support assembly defining an axial bore arranged to allow a removable capillary tube to extend therethrough; ions being received from the atmospheric pressure ion source through the capillary tube and directed towards the downstream aperture; and a jet disruptor, positioned downstream from the axial bore and configured to disrupt gas flow between the axial bore and the downstream aperture only when the capillary tube is not fully inserted through the axial bore.

A mass spectrometer includes an ionization assembly including an ionization chamber and at least one ion lens. The removable ionization assembly has a primary axis defined by the direction of an ion beam exiting the ionization assembly, and the ionization chamber and the at least one ion lens arranged along the primary axis. The mass spectrometer further includes an electron source aligned along the primary axis of the ionization assembly and a magnet assembly including a magnet. The electron source configured to provide an electron beam parallel to the primary axis. The magnet assembly movable between a first position in which the magnet is positioned to allow removal of the ion source and a second position in which the magnet is aligned with the electron source.

The invention relates to the detection of non-metabolized vitamin D. In a particular aspect, the invention relates to methods for detecting underivatized non-metabolized vitamin D by mass spectrometry.

A method of ionizing a sample is disclosed that comprises heating a sample so that analyte is released from the sample, producing charged particles such as charged droplets downstream of the sample, and using the charged particles to ionize at least some of the analyte released from the sample so as to produce analyte ions.

The present invention relates to a reaction chamber (12) for an IMR-MS apparatus or a PTR-MS apparatus, comprising an essentially gaslight outer housing (14), comprising at least two ion lenses (16) with essentially constant orifice dimensions and/or at least two ion lenses (17) with different orifice dimensions arranged around the reaction region (20), and at least one at least partly gaslight sealing (19), characterized in that the ion lenses (16,17) are placed inside the essentially gaslight outer housing (14), wherein between at least two adjacent ion lenses (16,17) an at least partly gaslight sealing (19) is mounted, wherein the room between at least other two ion lenses (16, 17) is such to allow a gas flow through said room from the reaction region (20) into the outer space (21). The present invention further relates to a method to operate an apparatus according to the invention.

This disclosure provides quantitative, rapid, and reliable LC-MS/MS methods for analyzing panels of pesticides and mycotoxins in various samples, including very hydrophobic and chlorinated compounds normally analyzed on a GC-MS/MS system. The methods can be carried out using a single instrument and can detect and quantify levels of the pesticides and mycotoxins that are well below action limits specified by U.S. states (e.g., California) and other countries (e.g., Canada) for these compounds in cannabis products.

Described herein are monitoring systems and methods, including for airborne molecular contamination (AMC), that combine a sampler, such as an impinger or sorbent tube with a real time analyzer, such as an ion mobility spectrometer (IMS) or optical particle counter. The system may allow for selective sampling in which the sampler is only exposed to the target fluid during periods in which the real time analyzer detects analytes, such as molecular contamination or particles, meeting particular criteria such the composition and/or concentration of analytes. The invention also includes impinger systems having a sampler reservoir comprising an anion leaching resistant material characterized by low anion leach rates in the presence of deionized water.

The invention relates to the detection of non-metabolized vitamin D. In a particular aspect, the invention relates to methods for detecting underivatized non-metabolized vitamin D by mass spectrometry.

A spray area in which a large number of droplets of a liquid sample sprayed from a spray nozzle (3) is separated from the tip of a needle electrode (14) for corona discharge by a sufficiently large distance, with a grid electrode (15) facing the needle electrode (14) placed in between. Ring electrodes (16) for creating an electric field which drives primary ions that should react with the sample and generate sample-derived ions are provided within an ion chamber (10) between the grid electrode (15) and the spray area. Primary ions generated by corona discharge within the space between the needle electrode (14) and the grid electrode (15) pass through the opening of the grid electrode (15), reach the spray area under the effect of the electric field, and ionize sample components. Since the droplets are prevented from adhering to the needle electrode (14), the corona discharge is maintained in a stable state. The resultant primary ions are efficiently transported and used for the ionization of the sample. Therefore, no spike noise due to an unstable corona discharge occurs, so that a high-quality spectrum can be obtained.