A liquid junction assembly for providing a flow connection between two tubular conduits. The assembly includes respective bodies configured to define elongated passages of respective first and second cross sections to receive and locate the respective tubular conduits, a plate with at least one hole therethrough of a third cross section smaller than the first and second cross sections, and a seat for the plate, defined in a face of one or both of the bodies. The bodies and the plate are assembled with the plate in the seat and the elongated passages and the hole aligned along a common axis.

The present invention relates to a system and method for carbohydrate analysis in a flow chemistry manner. The present invention at least features continuous reactions of glycan hydrolysis in combination with saccharide labeling which is helpful to improve the existing approaches in glycan structural analysis.

A system for sampling a sample material includes a probe which can have an outer probe housing with an open end. A liquid supply conduit within the housing has an outlet positioned to deliver liquid to the open end of the housing. The liquid supply conduit can be connectable to a liquid supply for delivering liquid at a first volumetric flow rate to the open end of the housing. A liquid exhaust conduit within the housing is provided for removing liquid from the open end of the housing. A liquid exhaust system can be provided for removing liquid from the liquid exhaust conduit at a second volumetric flow rate. A droplet dispenser can dispense drops of a sample or a sample-containing solvent into the open end of the housing. A sensor and a processor can be provided to monitor and maintain a liquid dome present at the open end.

Using ion mobility separation to improve a duty cycle of a mass spectrometer is described. In one aspect, a mass spectrometer can use an ion-mobility spectrometer to allow for more multiply-charged ions to transmit through than singly-charged ions. This results in a mass analyzer to perform a mass analysis with more multiply-charged ions.

As a technique for separating odorous compounds by using a supercritical fluid chromatograph, a method for separating an odorous compound is provided which includes a process of carrying a sample containing an odorous compound into a column filled with a packing material made of a polymer having an unsaturated hydrocarbon structure, by a flow of a mobile phase which is a supercritical fluid of a predetermined substance.

A method and corresponding apparatus are disclosed for analysis of a peptide-containing sample. The sample is prepared by adding isotopically-labeled peptides corresponding to endogenous peptides of interest, and the prepared sample is analyzed by liquid chromatography-mass spectrometry (LCMS). Detection in a high-resolution, accurate mass (HRAM) MS1 spectrum of a precursor ion matching an isotopically-labeled peptide triggers acquisition of an MS/MS spectrum (preferably acquired in an ion trap or other fast mass analyzer) to determine if a product ion is present matching a characteristic product ion (e.g., the y.sub.1 ion) of the isotopically-labeled peptide. If the characteristic product ion is present, then a HRAM MS/MS spectrum is acquired for detection and quantitation of the corresponding endogenous peptide.

Compositions and methods for identifying free thiols in protein are provided. An exemplary method labeling peptides with a tag to identify free thiols and a tag to identify native disulfide bonds and analyzing the tags using targeted MS.sup.2. In one embodiment, the method provides complete coverage of all 32 cysteine residues in an IgG molecule. In other embodiments the method covers the 16 cysteine residues on the heavy and light chains in an IgG molecule. In another embodiment, the method covers the 5 cysteine residues on each light chain of an IgG molecule. In another embodiment, the method covers the 11 cysteine residues on each heavy chain of an IgG molecule.

Provided herein are systems that include: a mass spectrometry device configured to (i) generate a peak representing a drug in an extracted DBS sample from a pregnant subject after a treatment for multiple sclerosis to the pregnant subject has been administered and (ii) generate a peak representing an internal standard; a computer-readable memory including computer-executable instructions; and one or more processors communicatively coupled to the mass spectrometry device and configured to execute the computer-executable instructions, wherein when the one or more processors are executing the computer-executable instructions, the one or more processors are configured to carry out operations including: determining a peak area ratio of the drug in the extracted DBS sample to the internal standard; and identifying the administered treatment as being below an internal standard threshold when the peak area ratio of the drug in the extracted DB S sample to the internal standard is less than 1. Also provided herein are dried blood spot cards, and kits that include a dried blood spot card pre-treated with at least one internal standard.

The present disclosure relates to compounds useful for the detection or modulation of target nucleic acids, including DNA and RNA. The present disclosure further relates to methods for treatment of trinucleotide repeat disorders, which can include administration of oligonucleotide analogues that can bind pathogenic nucleotide repeats in DNA or RNA.

One mode of a chromatograph mass spectrometer according to the present invention includes: a measurement unit (1) that includes a chromatograph unit (1A) and a mass spectrometry unit (1B) capable of performing MS/MS analysis, and collects chromatograph mass spectrometry data having three dimensions of time, m/z, and a signal intensity by repeatedly performing the MS/MS analysis by data independent analysis in the mass spectrometry unit on a sample containing a compound separated by the chromatograph unit; a component detection unit (42) that detects a compound and a component corresponding to a partial structure of the compound by obtaining MS/MS spectra of a bar graph presentation based on chromatograph mass spectrometry data over a predetermined m/z range for a target sample, estimating precursor ion peaks in each of the MS/MS spectra, and selecting peaks based on a predetermined standard regarding an m/z direction in each of the MS/MS spectra and a predetermined standard regarding a time direction for peaks that can be considered to be identical or an identical group on the MS/MS spectra; a narrowing unit (43, 44) that narrows down components to be analyzed by performing screening using prior information on the detected component; and a composition estimation unit (45) that, by using m/z information corresponding to a narrowed down component, estimate a composition or a chemical formula of the component.