The invention relates to a method and apparatus for evaluating reaction molecular byproducts of pyrotechnic reactions. A closed calorimetry bomb holds pyrotechnic material, which is detonated by a charge. The calorimetry bomb is vented directly into a gas chromatography machine, where gas phase molecules are separated based on their polarity. The separated molecules are then injected into a mass spectrometer and characterized by their mass fragmentation. The remaining residual solids within the bomb are extracted and injected into a liquid chromatography instrument where they are separated by their polarity. The separated molecules are then injected into a mass spectrometer and characterized by their mass fragmentation pattern. The method provides a complete picture of the reaction pathways and products to aid in regulatory compliance of incorporating energetic materials into real-world applications, particularly those in the family of PFAS containing compositions.

A method of analyzing phenylhydrazine content in a 3-methyl-1-phenyl-2-pyrazolin-5-one active pharmaceutical ingredient includes obtaining a first measured value by measuring a phenylhydrazine content of a standard solution including phenylhydrazine or a salt thereof, a first acidic water and a first water-soluble organic solvent and having a phenylhydrazine concentration of 0.01 μg/mL to 10 μg/mL, obtaining a second measured value by measuring a phenylhydrazine content in a sample solution including a 3-methyl-1-phenyl-2-pyrazolin-5-one active pharmaceutical ingredient, a second acidic water and a second water-soluble organic solvent, and detecting a phenylhydrazine content in a 3-methyl-1-phenyl-2-pyrazolin-5-one active pharmaceutical ingredient based on the first measured value and second measured value. The first acidic water is hydrochloric acid, and/or an aqueous acetic acid solution, the first water-soluble organic solvent is acetonitrile and/or methanol, the second acidic water is hydrochloric acid, and/or an aqueous acetic acid solution, and the second water-soluble organic solvent is acetonitrile and/or methanol.

The present invention discloses a method for judgment of cheddar cheese grade based on identification characteristic flavor compounds, comprising the following steps: selecting cheddar cheese of different grades as standard product, and extracting volatile flavor compounds from the standard product; using gas phase-sniffing device to screen out characteristic flavor compounds with higher flavor intensity from the volatile flavor compounds through aroma extract dilution analysis; proceeding with clustering of characteristic flavor compounds as screened out to obtain identification characteristic flavor compounds of cheddar cheese; measuring the concentration of identification characteristic flavor composition of cheddar cheese of known grade, and establish the training set for training of support vector machine; measuring the concentration of identification characteristic flavor composition of cheddar cheese to be tested, and inputting it into the support vector machine trained to judge the grade of cheddar cheese to be tested. The present invention aims to obtain the model of identification characteristic flavor compounds of cheddar cheese through statistical analysis, which is available for accurate judgment of cheddar cheese quality grade on this basis.

The present disclosure provides methods of preparing breast milk for analysis analyzing breast milk, determining reference ranges for analytes in breast milk and testing breast milk for a panel of analytes. Aspects of the present disclosure provide dietary and lifestyle recommendations for the lactating mother-based on measured concentration of analytes. Retesting is disclosed to measure the influence of maternal diet on breast milk composition.

A sample is dissolved in a reagent 4 containing an organic solvent in a conversion vessel 11. A gas is supplied from a first gas supply part into the conversion vessel 11 via a reagent introduction tube 17, and thus the interior of the conversion vessel 11 is pressurized. A gas is supplied from a second gas supply part into the reagent 4 in the conversion vessel 11 via a reagent discharge tube 18, and thus gas bubbles 41 are formed in the reagent 4.

The present invention discloses a chromatographic analysis device based on a multifunctional integrated probe, and a use method of the chromatographic analysis device. The chromatographic analysis device integrates chromatographic sampling, sample injection and separation functions into the integrated probe. Meanwhile, the present invention further discloses a method for performing microsample analysis by the chromatographic analysis device based on the multifunctional integrated probe. The present invention has the main advantages as follows: the device is high in integration level, small in dead volume, simple in structure, convenient to use and particularly suitable for microsample analysis with a small sample amount, provides a new chromatographic sample injection mode for chromatographic analysis, and provides an ideal platform for chromatographic analysis and on-site chromatographic analysis of a trace amount of samples.

Methods for preparing labeled glycosylamines from a complex matrix are provided. The methodology includes the steps of: denaturing glycoproteins in a complex matrix to form a denatured complex matrix mixture; loading the denatured complex matrix mixture onto a MWCO filtration device; adding a glycosidase enzymatic solution onto the MWCO filtration device to form a deglycosylated complex matrix mixture comprising glycosylamines; collecting glycosylamines released from the MWCO filtration device; and derivatizing glycosylamines with a rapid tagging reagent to form a plurality of labeled glycosylamines suitable for detection in various liquid chromatography systems and detectors.

Disclosed is a detection method for N-nitrosodimethylamine (NDMA) impurities, comprising: (1) obtaining a test solution containing a sample to be tested; and (2) detecting the test solution by means of gas chromatography-mass spectrometry to determine the content of an N-nitrosodimethylamine impurity in the sample. The method provided in the present invention has a good separating effect, a wide linear range, a high sensitivity and a good method durability, and can detect the content of N-nitrosodimethylamine (NDMA) in the sample rapidly and effectively.

A diagnostic apparatus for analysing a sample to diagnose disease, the apparatus comprising: a separating element for separating gas derived from the sample into component parts; a sensor arrangement coupled to the separating element such that a component part of the gas is directed towards the sensor arrangement, the sensor arrangement being configured to detect compounds which may be indicative of disease; and a processing element coupled to an output of the sensor arrangement, the processing element being configured to process a signal output by the sensor arrangement to provide a diagnosis.

Provided are a pretreatment device capable of starting pretreatment in a simple operation, and an analysis system provided with the pretreatment device. A container holding unit 12 holds pretreatment containers into each of which a sample is injected, at a plurality of holding positions. A pretreatment unit sequentially performs pretreatment by using the pretreatment containers held at the holding positions of the container holding unit 12 in a specific order. A controller configured to receives a setting of the holding position of a pretreatment container to be used first among the plurality of holding positions in the case where a series of pretreatments using the plurality of pretreatment containers is started by the pretreatment unit.