Abstract: Provided herein are single-substance multi-point calibration techniques for quantitative mass spectrometry using the theoretical relative abundance of isotopes in a calibrator. Also provided herein are methods of determining the concentration of an analyte using a calibrator for the analyte.

Abstract: The present invention relates to a biomarker and a method for determining an oxidative stress level in a biological sample, which employs co-factor-dependent oxidative stress parameters, as well as a kit adapted for carrying out such a method. In one aspect the co-factor is tetrahydrobiopterin.

Abstract: The present invention relates to a biomarker and a method for determining an oxidative stress level in a biological sample, which employs co-factor-dependent oxidative stress parameters, as well as a kit adapted for carrying out such a method. In one aspect the co-factor is tetrahydrobiopterin.

Abstract: An apparatus and method analyzes a metabolic profile in a biological sample. The apparatus includes an input unit for inputting the drugs and/or metabolites to be screened; a controlling unit for determining a parameter set for metabolites preparation and for mass spectrometry analysis depending on the input of the kind of metabolites to be screened; a treatment unit for preparing the metabolites to be screened depending on the determined parameter set; a mass spectrometer for performing mass spectrometry analysis on prepared metabolites depending on the parameter set; a database for storing results of analyzing and parameter sets for metabolite preparation and for mass spectrometry analyses; and an evaluation unit for evaluating the results of mass spectrometry by use of reference results stored in the database to output an analysis of the metabolites profile.

Abstract: A device, in particular a sample preparation device for the quantitative analysis of a drug and/or metabolite profile in a biological sample, which includes an insert for such a device being impregnated with at least one internal standard, to the internal standard itself, and to a kit comprising the device. Further, the invention also relates to an apparatus containing the device, and to a method for the quantitative analysis of a drug and/or metabolite profile in a biological sample employing the device.

Abstract: The present invention relates to a method for determining the systemic metabolic status of an organism in relation to inflammation and oxidative stress using a biological sample (Inflammation and Oxidative Stress Level Assay). This comprises detection and quantification of one or more derivatives of arachidonic acid (eicosanoids), linoleic acid and/or docosahexaenoic acid, preferably together with one or more oxidative stress parameters and/or with one or more analytes from other metabolite classes in parallel, as well as a kit adapted for carrying out such a method. Moreover, the invention relates to the biomarkers as employed in the method.

Abstract: Methods for producing glycan nitrones comprising reacting glycans with a mono-N-substituted hydroxylamine at pH 6 or greater to form glycan nitrones. Methods for producing glycan derivatives comprising reacting glycan nitrones produced by reacting glycans with a mono-N-substituted hydroxylamine at pH 6 or greater with a reducing agent to form hydroxylamine glycan derivatives and uses of the glycan nitrones and hydroxylamine glycan derivatives produced by the methods.