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.

The invention relates to the detection of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). In a particular aspect, the invention relates to methods for detecting DHA and EPA by mass spectrometry and kits for carrying out such methods.

In an embodiment of the present ambient ionization experiment, the abundance of background chemicals relative to ions of interest is decreased by pulsing the carrier gas used to generate the excited species directed at the sample. The excited species are stepwise directed at the sample reducing the overall abundance of background chemicals introduced into the ionizing region. In an embodiment of the present ambient ionization experiment, the combination of stepping the sample in front of the excited species and pulsing the carrier gas used to generate the excited species increases the sensitivity of detection.

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.

The invention generally relates to systems and methods for conducting reactions and screening for reaction products.

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.

Disclosed is a device to generate ions from a deposited sample, comprising: A chamber which is arranged and designed to keep the deposited sample in a conditioned environment comprising a dopant gas, A desorption device which is arranged and designed to desorb the deposited sample in the chamber using an energy burst, An ionization device which, for the purpose of ionization, is arranged and designed to irradiate the desorbed sample in the chamber using coherent electromagnetic waves or expose it to an electric discharge, a plasma, or light of an arc discharge lamp with broadband emission spectrum, which are chosen such that the dopant gas is receptive to them, and An extraction device which is arranged and designed to extract ions from the desorbed sample and transfer them into an analyzer. Disclosed is also a method which is preferably conducted on such a device.

The invention generally relates to systems and methods for conducting reactions and screening for reaction products.

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.

This disclosure presents inventions for ionization, for example, for use in mass spectrometer devices and methods. In an embodiment, a device is provided for introduction of pulses of a first carrier gas into an ionization chamber and introduction of a second carrier gas into the ionization chamber. Electrodes in the chamber ionize the carrier gas and direct the ionized gas toward a sample for analysis. The second carrier gas can either assist in washing out the first carrier gas or may become ionized along with the first carrier gas to improve ionization of an analyte. In an embodiment, a method for producing ionized carrier gasses is provided.