A first reference line that is a regression line obtained from data within a predetermined range including a starting point of a peak detected from data of a graph showing changes in intensity with respect to a parameter, a second reference line that is a regression line obtained from data within a predetermined range including a ending point of the peak, and a third reference line connecting the starting and ending points, and one or more intermediate control points in a triangle defined by the first, second, and third reference lines are determined; and a Bezier curve between the starting point and the ending point is created to be determined to be a baseline of the peak, the Bezier curve being determined by control points of the starting point, the one or more intermediate control points, and the ending point in order on a parameter axis.

A method for detecting a peak in data of a chromatogram or a spectrum, includes: detecting multiple tentative peaks in the data on the basis of a predetermined criterion; determining an actual measurement value of a predetermined feature value indicating a size of a tentative peak from each of the detected multiple tentative peaks, the feature value; determining a smoothed curve on the basis of respective horizontal axis values and actual measurement values of the multiple tentative peaks; determining a reference value of the feature value with respect to each of the multiple tentative peaks from the smoothed curve; and detecting, of the multiple tentative peaks, a tentative peak whose actual measurement value is within a predetermined range from the corresponding reference value as a true peak. Only tentative peaks whose actual measurement value is within a predetermined range from the corresponding reference value as a true peak.

Components resolved in time by a separator accumulate in a sample cell and are analyzed by electromagnetic radiation-based spectroscopic techniques. The sample cell can be configured for multiple path absorption and can be heated. The separator can be a gas chromatograph or another suitable device, for example a distillation-based separator. The method and system described herein can include other mechanical elements, controls, procedures for handling background and sample data, protocols for species identification and/or quantification, automation, computer interfaces, algorithms, software or other features.

Wavelength spectrums of peaks detected on a chromatogram based on observation data to be processed are extracted to create a spectrum set in which the intensity values of the spectrums are normalized. One wavelength spectrum is selected from the set, and a vector of the wavelength spectrum at each point in time of measurement based on the observation data is projected so as to be perpendicular to the vector of the selected spectrum. The vectors of the wavelength spectrums in the set are also similarly projected. Consequently, the selected spectrum is erased from the set. The processes are repeated until the set does not include a spectrum, and the obtained signals are added. The signal resulting from the addition is a signal indicating the waveform shape of an unknown baseline.

A processor obtains a first correspondence in which at least one reference peak detected from reference chromatogram data and at least one target peak detected from target chromatogram data are brought in correspondence with each other, obtains a second correspondence in which a reference data set included in the reference chromatogram data and a target data set included in the target chromatogram data are brought in correspondence with each other, by using a first similarity between the second correspondence and the first correspondence, and corrects a time axis of the target chromatogram data in accordance with the second correspondence.

A controller of a liquid chromatograph is configured to execute, as an analysis operation in an analysis unit, a sample injection step of bringing a high-pressure valve into a loading state, sucking a sample from a tip of a needle to hold a sample in a sampling channel, then connecting the sampling channel to an injection port and bringing the high-pressure valve into an injecting state, and supplying a mobile phase from a liquid supplier, thereby injecting a sample held in the sampling channel into an analysis channel, and an analysis step of separating components of a sample injected into the analysis channel in a separation column by bringing the high-pressure valve in the loading state and supplying the mobile phase from the liquid supplier after the sample injection step is ended. The controller is configured to execute, as the analysis operation, a system cleaning step of cleaning a liquid flowing route.

Components resolved in time by a separator accumulate in a sample cell and are analyzed by electromagnetic radiation-based spectroscopic techniques. The sample cell can be configured for multiple path absorption and can be heated. The separator can be a gas chromatograph or another suitable device, for example a distillation-based separator. The method and system described herein can include other mechanical elements, controls, procedures for handling background and sample data, protocols for species identification and/or quantification, automation, computer interfaces, algorithms, software or other features.

A method to filter out pump pulses from data collected with a chromatography system is disclosed. Baseline data is collected as a pump delivers solvent to an analytical instrument, which may be the IP signal of a capillary bridge viscometer. A Fourier transform is applied to the data to generate the power spectrum of the baseline signal. Fundamental and harmonic frequencies are determined and a comb filter is constructed therefrom and applied to sample collected from all of the affected instruments. The comb filter may be correlated to the pump and flow rate and stored in data analysis software or database. Other systems using other pumps may also generate associated comb filters, and the resulting filters and the flow rates at which they were generated may be stored in a database accessible to the data analysis software.

A thermal conductivity detector includes a switch controllable to short-circuit the input of an amplifier to improve the thermal conductivity detector for use in gas chromatography without the need of an additional reference cell, wherein a digital signal processor calculates a transfer function of an analog signal processor from a digitized difference signal received in response to short-circuiting the input of the amplifier at a given time when solely a reference carrier fluid passes through a measuring cell, and the digital signal processor recovers a detector signal by deconvoluting the digitized difference signal with a transfer function.

Methods and systems for determining relative response factors for liquid chromatography using both molar concentration-based detection and mass concentration-based detection are described herein. A method includes determining a relative response factor for a compound based on the ratio of a molar-based peak area for the compound to the logarithm of the mass-based peak area for the compound and based on the ratio of a molar-based peak area for a reference compound divided by the logarithm of the mass-based peak area for the reference compound.