A first chromatogram is obtained by analyzing a second standard sample by size exclusion chromatography analysis using a first detector. Also, a second chromatogram is obtained by analyzing a solvent for the second standard sample by size exclusion chromatography analysis using the first detector. Then, from the difference between the first chromatogram and the second chromatogram, a third elution time in size exclusion chromatography analysis of the second standard sample using the first detector is determined.

An improved calibration process for a medical testing machine. The machine automatically recognizes that a package of calibration material has been inserted into it, and performs a calibration sequence to ascertain a calibration parameter to be used in performing future tests with the medical testing machine. The calibration package may include machine-readable indicators that the package is to be used for calibration, and of a calibration setpoint of a calibration material in the package. A calibration material may be stored in a lyophilized state in the package, and the medical testing machine may automatically reconstitute the lyophilized material.

The disclosed invention is in the field of analytical chemistry. In particular, it relates to methods for improved quantification of analytes in complex mixtures, and to compositions comprising precise amounts of said analytes. The improved method uses stable reference standards.

Methods are provided for making rapid labeled dextran ladders and other calibrants useful in liquid chromatography. The methodologies include a two-step process comprising a reductive amination step of providing a reducing glycan and reacting it with a compound having a primary amine to produce an intermediate compound. The intermediate compound is then rapidly tagged with a rapid tagging reagent to produce the rapid labeled dextran ladder.

A method for detecting a residual crosslinking aid in a crosslinked resin molded body includes a subject heating step in which a crosslinked resin molded body is heated at a temperature of 500° C. or higher and 700° C. or lower for a time of 3 seconds or more and 30 seconds or less, a subject analysis step in which gas chromatographic analysis is performed on a gas generated in the subject heating step, and a detection step in which an unreacted crosslinking aid is detected on the basis of a peak originating from a residual crosslinking aid in a chromatogram obtained in the subject analysis step.

A method for securing qualitative and quantitative information of a high molecular weight additive in a polymer resin sample is disclosed herein. In some embodiments, the method includes separating a fraction of a polymer resin sample using size exclusion chromatography (SEC), wherein the fraction corresponding to a high molecular weight additive, pyrolyzing the fraction in a pyrolysis-gas chromatography/mass spectrometer (Py-GC/MS) to obtain a mass spectrum of the pyrolyzed fraction; identifying a structure of the high molecular weight additive by comparing m/z values for fragment peaks in the mass spectrum to m/z values for fragment peaks in a mass spectrum of a standard, and determining the amount of the high molecular weight additive in the polymer resin sample, relative to the total weight of the polymer resin sample by comparing a sum of areas of the fragment peaks to a calibration line of the standard.

The present disclosure is directed to methods of characterizing a system containing a chromatographic column. The methods can include introducing a sample comprising a positive control and a negative control to the system containing a chromatographic column, wherein the positive control is a sensitive probe that interacts with the system and the negative control is substantially non-interacting with the system; after passing the sample through the chromatographic column, detecting the positive control and the negative control; and determining system suitability by comparing the amount of detected positive control to negative control. In some embodiments, determining system suitability (e.g., inertness of sample to the system) is accomplished by determining a ratio of detected positive control to negative control.

The present invention provides reagents for instrumentation quality control and methods of use thereof. In particular, sets of peptides or other molecules are provided for evaluating the performance of instruments with mass spectrometry (MS) and/or liquid chromatography (LC) functionalities.

A method for securing qualitative and quantitative information of a high molecular weight additive in a polymer resin sample is disclosed herein. In some embodiments, the method includes separating a fraction of a polymer resin sample using size exclusion chromatography (SEC), wherein the fraction corresponding to a high molecular weight additive, pyrolyzing the fraction in a pyrolysis-gas chromatography/mass spectrometer (Py-GC/MS) to obtain a mass spectrum of the pyrolyzed fraction; identifying a structure of the high molecular weight additive by comparing m/z values for fragment peaks in the mass spectrum to m/z values for fragment peaks in a mass spectrum of a standard, and determining the amount of the high molecular weight additive in the polymer resin sample, relative to the total weight of the polymer resin sample by comparing a sum of areas of the fragment peaks to a calibration line of the standard.

A system for providing standard mixtures of volatile and semi-volatile organic compounds for simultaneous GC and MS calibration in a calibration vial, wherein calibration mixtures are prepared by diluting calibration analytes in granular PDMS such that most of the analytes are in the PDMS phase and the sample can then be taken from the analytes in the headspace vapor in the calibration vial, wherein a reliable calibration sample can be taken from the calibration vial because the analytes in the PDMS phase and the headspace vapor are in thermodynamic equilibrium, and wherein the method provides solvent-less sampling, long-time stability, ease of use, is quantifiable, and related to temperature.