A GC sample carbon ladder is generated with the help of one or more of the following techniques: correction of solvent effects; fit analysis of the spectrum obtained for a target member of the carbon ladder and a reference spectrum; fit analysis of a sample carbon ladder in comparison with reference spectral features; constraints for proper order of elution; and/or inclusion of all members in a selected carbon ladder set.

Chromatographs of a measurement target sample measured in FID and MS are displayed on display unit in a time range defined with reference to the retention index of the target component computed based on the standard retention time and calibration retention time for the target component in FID. The retention index is not readily influenced by difference in column length, thus making it possible to display the peaks of the target component measured with FID and MS in a corresponding time range by displaying the chromatograms on display unit in a time range defined with reference that retention index. Therefore, even in cases where the retention times of the target component in FID and MS are different, measurement results for an identical target component from FID and MS can be easily compared.

Methods for transferring a separation procedure from a first chromatographic system to a second one are disclosed that involve substantially matching a pressure profile. In some such methods, a length, an area, and a particle size of a first column in the first system and a flow rate in the first separation procedure are identifiable. Some such methods also involve selecting a combination of a length, an area, and a particle size of a second column in the second system and a flow rate for the second separation procedure. These methods may involve calculating a target length, a target area, or a target particle size for the second column in the second system or a target flow rate for the second separation procedure.

Methods for transferring a carbon dioxide based separation procedure from a reference chromatographic system to a target chromatographic system involve alternative techniques for determining system pressure drops not attributable to the column. One technique involves leveraging experimental chromatography to develop a correction factor that is a function of at least one correction coefficient and at least one ratio of the differential analyte retention time to the retention time in the reference system. Another technique involves leveraging other experimental measurements of tubing pressure drops under various condition to develop a lookup table that can be used to identify likely tubing pressure drops in the target system. A third technique leverages knowledge of the separation procedure and the target system and the likely nature of the relevant flow to calculate tubing pressure drops in the target system.

A thermal desorption tube for chromatography and mass spectrometry analysis. The thermal desorption tube includes a sorbent and a plurality of focusing agents loaded at known, relative amounts onto the sorbent. Each focusing agent is a compound that chromatographically elutes within a retention time similar to a retention time of a target analyte and has a mass spectrum similar to a mass spectrum of the target analyte. The thermal desorption tube is configured to be further loaded with a sample having the target analyte.

Exemplary embodiments provide methods, mediums, and systems for analyzing spectrometry and/or chromatography data, and in particular to techniques to improve the reproducibility of results of spectrographic and/or chromatographic experiments. For example, some embodiments provide techniques for normalizing mass spectrometry (MS) and/or liquid chromatography (LC) data across different experimental devices, allowing data from different cohorts to be directly compared. To this end, exemplary embodiments provide a reliable, reproducible target library usable across different platforms, laboratories, and users. One embodiment leverages statistical techniques to select experimental parameters configured to reduce or minimize the chance of misidentifying a target molecule. Another embodiment leverages the law of large numbers to produce a composite product ion spectrum usable across different experiments. The composite product ion spectrum allows regression curves to be generated, where the regression curves can be used to normalize an experimental mass spectrum.

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 object of the present disclosure is to find a method in which a result of liquid chromatography can be predicted with high accuracy for a wide range of a mixing ratio of solvents by utilizing a result of thin-layer chromatography.

A liquid chromatography method for separating a mixture of two or more kinds of compounds, comprising the following steps: (1) performing thin-layer chromatography or column chromatography in a mixed solvent of two or more kinds of solvents having a different mixing ratio from each other or a single solvent; (2) creating a relational expression between a mixing ratio and an elution degree of a solvent for each compound in a sample based on a result of the step (1); and (3) determining an optimum condition based on the relational expression, and performing liquid chromatography.

A liquid chromatography method for identifying an analyte of interest utilizing as retention index standards a homologous series of neutrally charged compounds having at least one functional group bearing a positive charge and at least one functional group bearing a negative charge. The method is especially useful for liquid chromatography-mass spectrometry (LC-MS) methods, more especially for LC-MS methods employing electrospray (ESI) or atmospheric pressure chemical ionization (APCI) ionization systems.

A homologous series of neutrally charged compounds having at least one functional group bearing a positive charge and at least one functional group bearing a negative charge are advantageous retention index standards for liquid chromatography, especially for liquid chromatography-mass spectrometry (LC-MS) methods, more especially for LC-MS methods employing electrospray (ESI) or atmospheric pressure chemical ionization (APCI) ionization systems.