A method and system for detecting pesticide residue in agricultural products. The system includes a chromatographic and mass-spectrometric system and a computer. The system inspects first and second sample solutions prepared from two identical extracts of an agricultural product. The first sample solution includes no additives while the second sample is added with a pesticide standard which is intended to be detected by the system for comparison. The computer compares the mass chromatograms of the first and second sample solutions, and calculate an increased integral area by which the peak of the second sample solution in the second mass chromatogram exceeds the peak of the first sample solution in the first mass chromatogram at the same retention time. As such, the concentration of pesticide residue in the sample can be determined by a ratio between the increased integral area and the concentration of the pesticide standard.

The invention relates to a method for the determination of crocetin and its derivative amounts and the derivative composition from gardenia yellow. The method mainly comprises of following steps: the absorbance measurement of a gardenia yellow aqueous solution at known concentration by UV-VIS, the absorption coefficient measurement of total crocetin derivative, the total crocetin derivative amount calculation according to Lambert-Beer law, the relative amount calculation of each crocetin derivative from its absorption coefficient and peak area on HPLC, the amount calculation of each crocetin derivative from the total amount of crocetin derivative and the relative amount of each crocetin derivative, and finally total crocetin amount calculation. In practice, the absorption coefficient of each crocetin derivative is calculated from that of its root structure, crocetin, based on the negative correlation-ship of absorbance with molecular mass of the molecule while the molecular mass of each crocetin derivative is substituted by the m/z value of its parent ion.

Based on three-dimensional data of time, wavelength and intensity acquired with a three-dimensional chromatograph, whether or not the peak-top intensity of the peak of a target component exceeds a predetermined upper limit is determined. If the intensity exceeds the limit, two wavelengths λ1 and λ2 are set in a spectrum passing through the peak top, where λ1 is the peak-top wavelength while λ2 is a wavelength which belongs to the peak and at which the intensity is within a predetermined range. For each point in time belonging to the target peak, the ratio between the intensity at λ1 and the intensity at λ2 in the spectrum at that point in time is calculated, and one of the calculated intensity ratios is selected as a correction value. Based on this correction value and a quantitative value calculated from a chromatogram at λ2, the quantitative value of the target component is determined.

A method evaluates a quality of a dephosphorylation reagent, the method including the steps of: providing a dephosphorylation reagent containing an alkaline phosphatase and a peptide fragment derived from the alkaline phosphatase; and evaluating the dephosphorylation reagent as having a high quality if a content ratio of the peptide fragment to the alkaline phosphatase is a predetermined reference value or less.

This tool utilizes orthogonality concepts used for analytical chromatography and apply them to chromatography for downstream processing applications utilizing a small set of product-agnostic, optimally orthogonal resins with which most separations (capture or polishing) can be accomplished. Libraries of components for separation mediums are provided. The library of components is administered to the separation mediums and combination of the separation mediums at varying pHs, and the separability and orthogonality of each is quantified. The separability is a measure of a probability that the separation mediums will separate a pair of components, whereas the orthogonality is a measure of the enhancement in separability upon addition of another separation medium. By identifying those combinations of separation mediums that not only provide advantageous separability, but also high orthogonality, sets of separation mediums can be more easily provided or wholly designed for use in processing applications.

A method is provided for detecting a polypeptide of interest in a plant without the use of a reference standard. The method comprises the steps of obtaining a plant expressing the polypeptide of interest and a negative control plant that does not express the polypeptide of interest, and analyzing a sample from each in an information-dependent acquisition (IDA) method. A method is also provided for determining the relative expression level of a polypeptide of interest in a plurality of plants without the use of a reference standard. This method comprises the steps of obtaining a plurality of plants expressing the polypeptide of interest and a negative control plant that does not express the polypeptide of interest, analyzing samples from each in an IDA method, and determining the relative expression level of the polypeptide in each of the plurality of plants.

A data processing device that processes three-dimensional data having time, intensity, and wavelength collected from a sample serving as a measurement target includes: a chromatogram generator configured to generate a chromatogram from the three-dimensional data; a target peak determiner configured to determine a target peak from peaks appearing on the chromatogram; a time point specifier configured to specify a time point at which the size of a spectrum matches the size of a reference spectrum from a time range during which the target peak appears in the three-dimensional data; and a target spectrum generator configured to extract data at the time point from the three-dimensional data, thereby generating a spectrum at the time point. With this configuration, a spectrum that is not affected by distortion, saturation, or noise can be readily and reliably obtained from the three-dimensional data obtained through sample analysis.

A peak-waveform conversion processor detects a peak in a profile spectrum created based on data obtained at each measurement point in a sample's measurement area, and acquires a rod-like peak by performing centroid conversion processing on a waveform of the peak having a mountain shape. When an operator specifies a target compound to be observed, a mass difference calculation unit calculates a mass difference between a precise m/z of the target compound and an m/z of a rod-like peak at a position close to the precise m/z for each measurement point. A mass difference image creator creates an image showing a distribution of mass differences based on the calculated mass differences. A mass difference related information calculation unit acquires an index value such as an average value of a plurality of mass differences for each mass difference image, and creates a graph showing a frequency distribution of the mass differences.

A peak-waveform conversion processor detects a peak in a profile spectrum created based on data obtained in each micro area in a measurement area, and acquires a rod-like peak by performing centroid conversion processing on a waveform of the peak in a mountain shape. When receiving a precise m/z value Ma of a target compound and an allowable range ΔM of m/z, an image creator determines whether or not there is a rod-like peak in a range defined by “Ma±ΔM”, for each micro area. When there is a rod-like peak, a height value of the rod-like peak is defined as the signal intensity value of the target compound in the micro area. In contrast, when there is no rod-like peak in the range defined by “Ma±ΔM”, the signal intensity value of the target compound in the micro area is set to zero.

Disclosed are methods for improving compound detection and characterization. Methods for characterizing a sample are disclosed. The methods can include providing a sample to a liquid chromatography system capable of sample separation to generate sample components; analyzing sample components by multiplexed targeted selected ion monitoring (SIM) to generate an inclusion list; and performing iterative mass spectral data-dependent acquisition (DDA) from the inclusion list, to identify individual sample components thereby characterizing the sample. In one example, multiplexed targeted SIMs and iterative MS2 DDA acquisition is used to increase robust compound identification for cell culture medium analysis.