187 results about "Instrumental chemistry" patented technology

The invention relates to an elemental analyzer, and in particular relates to a laser-induced breakdown spectroscopy (LIBS) elemental analyzer. An accurate target point positioning laser-induced breakdown spectroscopy elemental analyzer is mainly characterized by comprising a pulse laser, wherein a laser beam is conducted onto an analysis sample inside a sample room through a laser transmission system; an accurate target point positioning system is arranged on the sample room; a target sample emission spectrum is connected with a spectrograph through a transmission optical fiber of the accurate target point positioning system. The elemental analyzer has the advantages that the whole suit of LIBS analyzer consists of a laser system, a light guide system, a positioning system and the sample room which are independent, so that the elemental analyzer can be taken as one piece of equipment and also can be used by conveniently replacing laser sources with different parameters, or an in-situ sample can be directly analyzed without using the sample room; the application range of the analyzer is enlarged, and the practicability and the commercialization of an instrument are promoted. The accurate target point positioning system can realize the micron dimension positioning of three-dimensional space and the automatic correction of target points, so that the accuracy of measurement and analysis results of the analysis instrument is improved, and the sensibility of analytical elements of the instrument is promoted.

Systems and methods are described for laser ablation of an analyte from a specimen and capturing of the analyte in a dispensed solvent to form a testing solution. A solvent dispensing and extraction system can form a liquid microjunction with the specimen. The solvent dispensing and extraction system can include a surface sampling probe. The laser beam can be directed through the surface sampling probe. The surface sampling probe can also serve as an atomic force microscopy probe. The surface sampling probe can form a seal with the specimen. The testing solution including the analyte can then be analyzed using an analytical instrument or undergo further processing.

The invention provides an artificial intelligence-based food flavor sensory evaluation system and an establishment method thereof. The food flavor sensory evaluation system comprises a component sensory detection system, a computer intelligent analysis system and a food flavor database, wherein the component sensory detection system consists of a GC-MS and a GC-O; the GC-MS is used for obtaining flavor feature original data of foods; the GC-O is used for obtaining artificial sensory evaluation data of food flavors; the computer intelligent analysis system is used for performing preprocessing and feature extraction on the flavor feature original data and the artificial sensory evaluation data, and performing dimension reduction and clustering analysis on the original data; and the food flavor database is established by performing fitting analysis on the flavor feature original data and the artificial sensory evaluation data obtained by the sensory detection system by a computer, combines the flavor original data and the artificial evaluation data, and comprises various data of mutual association of food volatile components. The instrument analysis is combined with the human body sensory evaluation, so that the one-sidedness and the defect of manual repetitive detection in an existing food flavor detection method are overcome, and an evaluation result is more comprehensive and reliable.

The invention discloses an infrared spectroscopic analysis method of the integral quality characteristic of mainstream smoke of cigarette. The analysis of the integral quality characteristic of mainstream smoke of a cigarette sample is completed through smoke collection, power-on and pretreatment of a vacuum infrared spectrometer, background subtraction, spectrum acquisition and data analysis. The method is suitable for the analysis and detection of the integral quality characteristic of the cigarette smoke, can directly acquire the integral spectral information of the mainstream smoke without individually trapping a granule phase part by a Cambridge filter, enhances the analysis sensitivity of the above device through the background subtraction and data preprocessing, and allows the main component score of a sample to be conveniently calculated through combining a metrological calculating technology, and the score characterizes the integral quality characteristic of the mainstream smoke of the sample. The score can be widely applied to the classification, the true and counterfeit cigarette identification and the homogenization evaluation of different samples. The whole evaluation process is fast and accurate, and is highly sensitive, and the method provides effective technical support for the quality improvement and the synergism of cigarette products and the development of new products.

The invention discloses a pretreatment method for strong-polarity pesticide residue detection. The pretreatment method comprises the steps of extracting strong-polarity pesticides from a sample through a methanol aqueous solution, purifying an extracting solution through a dispersive solid-phase extraction agent, and filtering the extracting solution for instrument analysis. The pretreatment method disclosed by the invention is a complementation and an improvement on the existing QuEChERS method, so that the shortcoming that the conventional internationally accepted QuEChERS method cannot be used for detecting the strong-polarity pesticides is overcome. The pretreatment method is easy to operate and high in reproducibility; the recycling rate of a strong-polarity compound is effectively guaranteed; meanwhile, impurities in the sample extracting solution are effectively removed during purification, so that pollution to a detection instrument is relieved, and the detection sensitivity is greatly improved.

The invention relates to a gas chromatography-surface acoustic wave rapid analysis and determination method for aldehyde and ketone materials, which utilizes gas chromatography and a surface acoustic wave sensor to rapidly analyze the concentration of the aldehyde and ketone materials and belongs to an instrument analysis method. The rapid analysis and determination method of the invention comprises the following steps: sampling the aldehyde and ketone materials in air; preprocessing samples, i.e. enabling the samples to be reacted with 2, 4-dinitrophenylhydrazine to prepare phenylhydrazone corresponding to the aldehyde and ketone materials; and adopting the gas chromatography and surface acoustic wave rapid analysis instrument to analyze the samples. The method of the invention has the advantages of short analysis time, analysis solution on the surface acoustic wave sensor of the volatile aldehyde and ketone materials, great analysis sensitivity enhancement, convenient operation and site analysis realization.