Methods of quantifying a N.sup.2-(1-carboxyethyl)-2′-deoxyguanosine (CEdG) levels in biological samples and comparing those levels to known normal levels can diagnose a number of metabolic disorders or complications associated therewith, including diabetes, its associated complications, and cancer. Methods can also determine whether therapies for disorders are effective by measuring CEdG levels before and after treatment. Measurement of CEdG levels is achieved by using liquid chromatography electrospray ionization tandem mass spectrometry.

The invention discussed in this application relates to vitamin B12-based compounds that are useful as quantitative standards, particularly for the assessment of vitamin B12 deficiency.

Embodiments of the invention relate to the use of a melatonin agonist in the treatment of free running circadian rhythms in patients, including light perception impaired patients, e.g., blind patients, and to methods of measuring circadian rhythm.

A measurement data processing device for graphically displaying measurement data for a plurality of target compounds and for performing quantitative determination for the target compounds is provided. The device includes a display section 7, a measurement data input receiver 43 for receiving an input of measurement data, a screen-display numerical data creator 44 for performing a previously determined process on the measurement data to calculate a quantitative value and create numerical data for screen display, a screen-display graphical data creator 46 for performing a previously determined process on the measurement data for the target compounds to create graphical data for screen display after the numerical data for screen display have been created for all target compounds, and a display processor 48 for displaying, in the display section, the numerical data for screen display and the graphical data for screen display in a form that depends on a user operation.

Techniques and apparatus for evaluating analytical device performance and data quality are described. In one embodiment, for example, an apparatus may include at least one memory, and logic coupled to the at least one memory. The logic may be configured to generate an analysis method to be performed by an analytical device, the analysis method comprising a plurality of method segments comprising at least one performance assessment process and at least one sample analysis process, and link the at least one performance assessment process with the at least one sample analysis process. Other embodiments are described.

The invention provides a liquid chromatograph mass spectrometer which prevents contamination of a pump and a column and can perform mass calibration without adding a complicated mechanism. This liquid chromatograph mass spectrometer includes a liquid chromatograph including a liquid feed pump configured to feed a mobile phase solvent, a mass spectrometer configured to analyze a mass of a sample, and a standard sample container configured to be connected in series with the liquid chromatograph and the mass spectrometer in a flow path that connects the liquid chromatograph and the mass spectrometer and configured to house a standard sample for mass calibration.

The present invention relates to a method for providing information for the preemptive diagnosis of colorectal cancer with non-invasive biospecimens, wherein the excellent quantification of carcinogenic PhIP and MeIQx is achieved in terms of yields, when a biological sample, such as urine, is hydrolyzed with strong alkali reagents and then prepared through a specific liquid-liquid extraction, as compared to when the sample is prepared with other hydrolysis methods or extraction.

Provided are methods for determining the amount of estradiol in a sample using mass spectrometry. The methods generally involve ionizing estradiol in a sample and detecting and quantifying the amount of the ion to determine the amount of estradiol in the sample.

Provided is a method by which the disaccharides derived from glycosaminoglycans can be analyzed in a stable and highly reproduceable manner. A method for analyzing a glycosaminoglycan according to the present invention includes: a first process for producing a plurality of kinds of disaccharides derived from a glycosaminoglycan in a biological sample by adding a plurality of kinds of glycosaminoglycan-specific enzymes to the biological sample: and a second process for separating and analyzing the plurality of kinds of disaccharides by a liquid chromatography-mass spectrometry method, where a column used for liquid chromatography in the liquid chromatography-mass spectrometry method is a column packed with a stationary-phase support to which an amide group as a functional group is bound, or a column packed with a stationary-phase support to which an adamantyl group as a functional group is bound.

Provided are methods for quantifying peanut proteins in food products using a matrix-specific calibration curve. Methods provided include exposing a food sample comprising a matrix and one or more peanut proteins to an extractant to extract the one or more peanut proteins from the food sample; heating the food sample to reduce protein interference in the food sample; digesting one or more peanut proteins in the food sample to form one or more peanut peptides; determining a relative response value of the one or more peanut peptides in the food sample by analyzing the food sample using liquid chromatography with tandem mass spectrometry; and determining an amount of the one or more peanut proteins by comparing the determined relative response value of the one or more peanut peptides in the food sample to a matrix-specific calibration curve.