A method of performing mass spectrometry includes accumulating, over an accumulation time, ions produced from components eluting from a chromatography column and transferring the accumulated ions to a mass analyzer. During an acquisition, a mass spectrum of detected ions derived from the transferred ions is acquired. An elution profile is obtained from a series of acquired mass spectra including the acquired mass spectrum and a plurality of previously-acquired mass spectra. The elution profile includes a plurality of detection points representing intensity of the detected ions as a function of time. A current signal state of the elution profile is classified based on a subset of detection points included in the plurality of detection points. The accumulation time for a next acquisition of a mass spectrum is set based on the classified current signal state of the elution profile.

The present disclosure provides an improved method for accurately measuring the amino acid sequence of a therapeutic protein, in particular, an antibody, to insure the homogeneity of the protein such that it is suitable for administering to a human subject for treating a disease or disorder. The methods employ analytical physical chemistry techniques, in particular, a guided electron-transfer dissociation (ETD) and mass spectrometry (MS) approach for robust sequence coverage of the molecule with high accuracy and speed of use.

Provided is a method for simultaneously detecting Vitamin K1 and Vitamin K2 in traces of blood. The method includes: constructing a two-dimensional liquid chromatography-tandem mass spectrometer, establishing an analytical method, and detecting at least three mixed standard solutions using the constructed two-dimensional liquid chromatography-tandem mass spectrometer to obtain a first detection result; fitting standard curve equations respectively corresponding to Vitamin K1 and Vitamin K2; and mixing and centrifuging a blood sample to which an extraction reagent and a certain amount of internal standard substance are added, collecting a supernatant, blowing the supernatant to dry with nitrogen, redissolving the residue, and detecting the dry supernatant using the constructed two-dimensional liquid chromatography-tandem mass spectrometer to obtain a second detection result. In this manner, concentrations of Vitamin K1 and Vitamin K2 in the blood sample are obtained.

Provided are methods for determining the amount of tamoxifen and its metabolites in a sample by mass spectrometry. In some aspects, the methods provided herein determine the amount of N-Desmethyl Tamoxifen. In some aspects, the methods provided herein determine the amount of N-Desmethyl Tamoxifen and other tamoxifen metabolites. In some aspects, the methods provided herein determine the amount of tamoxifen, N-Desmethyl Tamoxifen, and other tamoxifen metabolites.

Use of a N,N,N-trimethyl-5-aminopentanoic acid antagonist in the preparation of a medicament for treating fatty liver or heart failure and a system for diagnosing fatty liver or heart failure. New treatment regimens are provided for fatty liver or heart failure. By antagonizing TMAVA, the levels of triglyceride and free fatty acids in the plasma and liver of a patient can be reduced, and at the same time, the inhibition effect of TMAVA on the activity of γ-isopropylbetaine hydroxylase can also be eliminated, and the weakening of free fatty acid mitochondrial β-oxidation caused by the decrease of endogenous carnitine synthesis is avoided. It is thus determined that reducing the ectopic accumulation of fatty acids in the liver and heart is clearly effective in treating fatty liver or heart failure.

Continuous analysis of ionic substances, such as oligonucleotide therapeutics, can be conducted over a long period of time while maintaining high sensitivity in liquid chromatography-mass spectrometry. An analysis method includes subjecting a sample containing an ionic analyte to liquid chromatography using a mobile phase containing a basic ion-pair reagent and further subjecting the analyte to mass spectrometry. An operation to prevent deterioration of the mobile phase can be conducted,

The present invention relates to a composition for screening various signal peptides to select specific ones that allow efficient secretion of a target protein to out of host cells. The present invention also relates to a method for selecting specific signal peptides that express a target protein in host cells and efficiently secrete the target protein to out of the host cells. The use of the composition and/or method according to the present invention enables ultrafast selection of optimal signal peptides for a target protein through barcoding sequences corresponding to the signal peptides, leading to the maximization of the production yield of the recombinant protein.

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.

A sample collection apparatus, being configured for preparing a plurality of liquid samples for a sample processing, includes a collection device including a plurality of collection vessels being configured for accommodating the liquid samples and for providing the liquid samples for the sample processing, wherein the sample collection apparatus is shaped for positioning the collection device directly in a carousel of an autosampler apparatus, in particular a liquid chromatography autosampler apparatus. Preferably, a holder device is provided which is configured for holding the collection device during collecting the liquid samples and during providing the liquid samples for the sample processing, and the holder device is shaped for positioning the holder device with the collection device directly in the carousel of the autosampler apparatus. Furthermore, a sample preparation apparatus including the sample collection apparatus and a sample collection method are described.

Methods and system for identification of dimer species using online chromatography and electrospray ionization mass spectrometry are provided. Also provided are methods and system for quantitation of heterodimer species using immunoprecipitation and liquid chromatography-mass spectrometry.