3 results about "Stable isotope ratio" patented technology

This invention discloses a method for determining the origin of tea based on the stable isotope ratio of EGCG monomers, belonging to the field of tea origin identification technology. It aims to solve the technical problem of insufficient accuracy in existing tea origin identification methods. The method involves measuring the overall stable isotope ratio δ in the tea sample. 13 C 茶叶 δ 15 N 茶叶 δ 2 H 茶叶 δ 18 O 茶叶 and the δ¹² value of stable isotope ratios of EGCG monomers 13 C EGCG δ 2 H EGCG and δ 18 O EGCG The preparation method of EGCG monomer involves making tea powder from tea samples, extracting and purifying epigallocatechin gallate (EGCG) monomer from the tea powder, and then determining the stable isotope ratio of the EGCG monomer. Based on the above stable isotope ratio, the origin of the tea sample is identified. This invention is mainly used for the accurate identification of tea origin, providing technical support for tea traceability and quality control.

The application belongs to the field of analysis and detection, and particularly relates to a method for detecting the content of directly absorbed exogenous glycine of microorganisms in soil, which comprises the following steps: firstly, mixing a double-labeled glycine solution with soil, adding sodium laureth sulfate and chloroform for fumigation, then extracting, deriving by hydrocarbonation reaction of ethyl bromoformate, and completing the extraction of glycine in microorganisms after stable layering by using sodium bicarbonate solution; and after the extraction is cracked by a stable isotope ratio mass spectrometer, exogenous glycine and original glycine in microorganisms are distinguished by characteristic ions to be determined. The method can effectively detect the content of directly absorbed exogenous glycine of microorganisms, is simple in operation, strong in specificity, has a good linear relationship, high sensitivity and accuracy, and effectively solves the problem that the content of directly absorbed exogenous glycine of microorganisms cannot be directly quantified. Thus, the direct utilization pathway of soil microorganisms to exogenous amino acid substances is quantitatively judged.

The application belongs to the field of analysis and detection, and particularly relates to a method for detecting the content of directly absorbed exogenous glycine of microorganisms in soil, which comprises the following steps: firstly, mixing a double-labeled glycine solution with soil, adding sodium laureth sulfate and chloroform for fumigation, then extracting, deriving by hydrocarbonation reaction of ethyl bromoformate, and completing the extraction of glycine in microorganisms after stable layering by using sodium bicarbonate solution; and after the extraction is cracked by a stable isotope ratio mass spectrometer, exogenous glycine and original glycine in microorganisms are distinguished by characteristic ions to be determined. The method can effectively detect the content of directly absorbed exogenous glycine of microorganisms, is simple in operation, strong in specificity, has a good linear relationship, high sensitivity and accuracy, and effectively solves the problem that the content of directly absorbed exogenous glycine of microorganisms cannot be directly quantified. Thus, the direct utilization pathway of soil microorganisms to exogenous amino acid substances is quantitatively judged.