A mixed-mode chromatography method for the determination of phosphorylated sugars in a sample is provided. The mixed-mode chromatography method includes obtaining a sample comprising at least one phosphorylated sugar. The sample is introduced onto a chromatography system. The chromatography system includes a column having a stationary phase material contained inside the column. The stationary phase material has a surface comprising a hydrophobic surface group and at least one ionizable modifier. The sample with a mobile phase eluent is flowed through the column, where the at least one phosphorylated sugar is substantially resolved and retained within seven minutes. The mobile phase eluent includes water with an additive and acetonitrile with the additive. The mobile phase eluent has a pH less than 6. The at least one phosphorylated sugar is detected using a detector.

The object of the present invention is to develop a reagent for optical resolution for the analysis of chiral amino acids wherein quenching is not exhibited. This object is achieved by providing a novel compound for optical resolution wherein quenching is not exhibited. The present invention relates to a novel compound, a reagent for optical resolution comprising the novel compound, a method for optically resolution comprising a step of reacting the novel compound, and optical isomers obtained by reacting the novel compound with amino acids.

The present invention relates to a method for determining the origin of glutamic acid in a sample and, in a broader sense, relates to a method for determining the origin of an amino acid. The present invention makes it possible to measure the stable isotope ratio, with a considerably higher accuracy than that of conventional methods, by measuring the 13C of glutamic acid (amino acid) by elemental analysis-stable isotope ratio mass spectrometry (EA-IRMS) and measuring the 15N by gas chromatography-stable isotope ratio mass spectrometry (GC-IRMS). In addition, the present invention makes it possible to determine the origin of glutamic acid (amino acid) by comparing the stable isotope ratio of the glutamic acid (amino acid) whose origin is unclear with the stable isotope ratio of glutamic acid (amino acid) whose origin is clear.

The present invention is a data-processing device used for a chromatograph which continuously performs a series of analyses for components in each sample while sequentially introducing a plurality of samples into a column. The device includes: an input section configured to allow for input of information into a schedule table for a plurality of analyses, the schedule table describing an analysis condition including a combination of the values of a plurality of control parameters, the order of execution of the plurality of analyses, and information for identifying a sample to be subjected to each analysis; a chromatogram creating means configured to receive data sequentially collected during two or more analyses and create a joint chromatogram from the data if the two or more analyses have been continuously performed for the same sample according to the schedule table; and a display means configured to display the joint chromatogram.

The present inventors discovered that compounds containing an amino group protected with a protecting group having an Fmoc skeleton can be quantitatively determined accurately by removing the protecting group having the Fmoc skeleton from the compounds and measuring the contents of dibenzofulvene or its derivative thereby produced.

Disclosed are methods, systems, and computer program products for using liquid chromatography/tandem mass spectrometry (LC-MS/MS) for the analysis of endogenous biomarkers, such as PGD.sub.2, in a biological sample. More specifically, the methods, systems, and computer program products are described for detecting and quantifying the amount of an PGD.sub.2 in a sample. The quantitative analysis may be helpful in making clinical diagnoses.

The apparatus for analyzing a disease sample according to the present invention includes: a member for separating and quantitatively determining an amino acid stereoisomer in a biological material from a subject; a member for obtaining a disease state index value through a calculation by substituting the amount of the amino acid stereoisomer into a discriminant equation; and a member for outputting disease state information on the subject on the basis of the disease state index value. The method for analyzing a disease sample according to the present invention includes: a step of measuring the amount of amino acid stereoisomers in a biological material from a subject; a step of obtaining a disease state index value through a calculation by substituting the amount of the amino acid stereoisomers into a discriminant equation; and the like.

This disclosure provides methods for quantifying individual amino acids in various bodily fluids obtained from a human patient. Also provided are reference ranges for normal amino acid levels in the various bodily fluids (e.g., blood plasma, urine, cerebrospinal fluid, and saliva) and for various age groups (e.g., neonates, infants, children, and adults).

The present invention relates to a multiresidual method for detecting and/or quantifying at least one amino acid or derivative thereof, at least one organic acid, and/or at least one modified nucleotide, in a sample of biological liquid or circulating cells, comprising the steps of: a) treating the sample with an extraction mixture at room temperature, preferably refrigerated at a temperature lower than ?20? C., comprising i) a mixture of one or more organic solvents having a final polarity index between 3 and 6, ii) a strong acid in an amount sufficient for the extraction mixture to have a normality from 0.005 to 0.025 N or a weak acid with ka in the range between 3.5?10?7 and 7.0?10?3 with a final concentration in the extraction mixture from 5 to 30 mM; wherein the extraction mixture comprises: acetonitrile, dichioromethane and formic acid; or acetonitrile and hydrochloric acid; or acetone and formic acid; or methanol and formic acid; or acetonitrile and formic acid; or methanol and dimethyl sulfoxide; or acetonitrile and dimethyl sulfoxide; or acetonitrile, methanol and hydrochloric acid; or acetonitrile and methanol; b) performing a hydrophilic interaction liquid chromatography (HILIC) on the sample treated in step a); c) performing an analysis by tandem mass spectrometry on the sample obtained in step b) detecting and/or quantifying the at least one amino acid or derivative thereof, and/or the at least one organic acid, and/or the at least one modified nucleotide.

Methods of analyzing purity of compositions comprising cysteamine and detecting impurities in cysteamine compositions are described.