The present invention generally pertains to methods of characterizing antibodies and related products. In particular, the present invention pertains to the use of immunoprecipitation and native strong cation exchange chromatography-mass spectrometry to specifically and sensitively detected and quantitate antibodies and related products in a sample.

A method for measuring a proportion of sA1c (%), which includes, when a peak derived from abnormal hemoglobin D, abnormal hemoglobin S or abnormal hemoglobin C is identified, calculation of the peak area, and measurement of the proportion of sA1c (%) corrected by using the calculation results. Results of measurement are obtained, by cation exchange chromatography, of sA1c (%) with a subject who provided a blood sample containing abnormal hemoglobin D, abnormal hemoglobin S or abnormal hemoglobin C by eliminating influences by such abnormal hemoglobin.

A method for measuring a proportion of sA1c (%), which includes, when a peak derived from abnormal hemoglobin D, abnormal hemoglobin S or abnormal hemoglobin C is identified, calculation of the peak area, and measurement of the proportion of sA1c (%) corrected by using the calculation results. Results of measurement are obtained, by cation exchange chromatography, of sA1c (%) with a subject who provided a blood sample containing abnormal hemoglobin D, abnormal hemoglobin S or abnormal hemoglobin C by eliminating influences by such abnormal hemoglobin.

A method may comprise forming a data matrix, extracting chromatographs of a mud filtrate and a formation fluid, extracting concentration profiles of the mud filtrate and the formation fluid, and decomposing a data set on an information handling machine using a bilinear model. A system may comprise a downhole fluid sampling tool and an information handling tool. The downhole fluid sampling tool may comprise one or more multi-chamber sections, one or more fluid module sections, one or more gas chromatographers, wherein the one or more gas chromatographers are disposed in the one or more fluid module sections, and an information handling system.

A method may comprise forming a data matrix, extracting chromatographs of a mud filtrate and a formation fluid, extracting concentration profiles of the mud filtrate and the formation fluid, and decomposing a data set on an information handling machine using a bilinear model. A system may comprise a downhole fluid sampling tool and an information handling tool. The downhole fluid sampling tool may comprise one or more multi-chamber sections, one or more fluid module sections, one or more gas chromatographers, wherein the one or more gas chromatographers are disposed in the one or more fluid module sections, and an information handling system.

A method of processing of a biological sample containing multiple metabolites is described The method comprising the steps of pre-treating the biological sample with a metabolite extraction solvent to provide a pre-treated sample, separating a first aliquot of the pretreated sample by reverse phase liquid chromatography (RPLC) to provide a first eluent containing resolved hydrophobic metabolites, and separating a second aliquot of the pre-treated sample by hydrophilic interaction liquid interaction chromatography (HILIC) to provide a second eluent containing resolved hydrophilic metabolites. The first and second eluents are assayed using targeted tandem mass spectroscopy operated in multiple reaction monitoring mode. Each liquid chromatography step (LC) is directly hyphenated with the tandem mass spectrometry (MS/MS) into a single LC-MS/MS analysis. The extraction solvent typically comprises methanol, isopropanol and an acetate buffer.

A method of processing of a biological sample containing multiple metabolites is described The method comprising the steps of pre-treating the biological sample with a metabolite extraction solvent to provide a pre-treated sample, separating a first aliquot of the pretreated sample by reverse phase liquid chromatography (RPLC) to provide a first eluent containing resolved hydrophobic metabolites, and separating a second aliquot of the pre-treated sample by hydrophilic interaction liquid interaction chromatography (HILIC) to provide a second eluent containing resolved hydrophilic metabolites. The first and second eluents are assayed using targeted tandem mass spectroscopy operated in multiple reaction monitoring mode. Each liquid chromatography step (LC) is directly hyphenated with the tandem mass spectrometry (MS/MS) into a single LC-MS/MS analysis. The extraction solvent typically comprises methanol, isopropanol and an acetate buffer.

Automated systems and methods for obtaining of the concentration of impurities in a liquid ethylene oxide product stream are shown and described. The systems and methods employ remote injection and flash vaporization of small volumes of liquid ethylene oxide into a carrier gas to minimize polymerization of the ethylene oxide and accumulation of polymerized ethylene oxide. Ethylene oxide peaks are diverted from the gas chromatograph effluent detector to stabilize baseline signal errors and avoid errors in the calculation of an impurity with an adjacent retention time peak. The systems and methods may be used for feedback, feedforward, dynamic matrix, and/or model-based predictive control of ethylene oxide purity. The systems and methods reduce lag times and errors associated with relying on laboratory analyses to make process adjustments.

This disclosure provides liquid chromatography tandem mass spectrometer (LC-MS/MS) methods and systems for detecting low levels of pesticides in a test sample. In the disclosed methods and systems, an ammonium salt is added to a mobile phase added to a liquid chromatography column or to the eluant from a liquid chromatography column. This addition improves the signal for certain pesticides by a factor of from 2 to 20, improving their detection limits in a variety of test samples.

Methods for determining the relative abundance of viral capsid components in a sample of viral particles are disclosed. In embodiments, methods for determining the relative abundance of empty capsids, partially-full capsids and full capsids (e.g., containing a heterologous nucleic acid molecule) of adeno-associated virus are disclosed.