Search

RU-2861593-C1 - METHOD FOR DETERMINING QUALITATIVE AND QUANTITATIVE CONTENT OF GLYCIDOL IN VEGETABLE OILS

RU2861593C1RU 2861593 C1RU2861593 C1RU 2861593C1RU-2861593-C1

Abstract

FIELD: analytical chemistry. SUBSTANCE: invention can be used in the fat-and-oil industry. A method for determining the qualitative and quantitative composition of glycidol in vegetable oil includes preparing reference samples of the compound to be determined, followed by analysing the reference samples on a gas chromatograph, constructing a calibration dependence and a regression equation for glycidol based on the obtained data, preparing the test sample, analysing the test sample, calculating the content of the compound to be determined in the test sample. The preparation of reference samples in unrefined oil and the test sample is carried out by mixing the reference samples and the test sample, respectively, with a solvent, subsequent enzymatic hydrolysis of the samples with a Candida rugosa lipase solution, heating them at a temperature of 80°C for 10 minutes, purification from free fatty acids with hexane, extraction of 3-MBPD with a mixture of diethyl ether – ethyl acetate in a ratio of 3:2, evaporating it in a stream of nitrogen, derivatisation of 3-MBPD with pentafluoropropionic anhydride (PFPA), dissolving the resulting PFPA 3-MBPD derivative in 0.5 ml of hexane, neutralising the excess PFPA with a 5% ammonia solution, analysing the hexane fraction on a gas chromatograph with an electron capture detector. The calculation of the content of the compound to be determined is carried out according to a pre-compiled equation describing the calibration line constructed in the coordinates of the values of the peak areas of the reference glycidol and the mass of the added reference component to be determined. EFFECT: expanding the arsenal of methods for determining glycidol, enabling the determination of glycidol in vegetable oils while maintaining high accuracy and speed of analysis when implementing this method. 1 cl, 1 tbl

Inventors

  • Zhdanov Dmitrii Dmitrievich
  • BUTINA ELENA ALEKSANDROVNA
  • Gerasimenko Evgenii Olegovich
  • Dubrovskaia Irina Aleksandrovna
  • Sonin Sergei Aleksandrovich
  • Loktionov Sergei Sergeevich

Dates

Publication Date
20260506
Application Date
20251218

Claims (9)

  1. A method for determining the qualitative and quantitative composition of glycidol in vegetable oil, including the preparation of reference samples of the compound to be determined, followed by analysis of the reference samples on a gas chromatograph, construction of a calibration curve and a regression equation for glycidol based on the data obtained, preparation of the test sample, analysis of the test sample, calculation of the content of the compound to be determined in the test sample, characterized in that the preparation of reference samples in unrefined oil and the test sample is carried out by mixing the reference samples and the test sample, respectively, with a solvent, subsequent enzymatic hydrolysis of the samples with a solution of Candida rugosa lipase, heating them at a temperature of 80 ° C for 10 minutes, purification from free fatty acids with hexane, extraction of 3-MBPD with a mixture of diethyl ether and ethyl acetate in a ratio of 3: 2, evaporation in a stream of nitrogen, derivatization of 3-MBPD with pentafluoropropionic anhydride (PFPA), dissolution of the resulting derivative of PFPA 3-MBPD in 0.5 ml of hexane, neutralization of excess PFPA with a 5% ammonia solution, analysis of the hexane fraction on a gas chromatograph with an electron capture detector, and calculation of the content of the compound to be determined is carried out according to a pre-compiled equation describing the calibration line, constructed in the coordinates of the values of the peak areas of the reference glycidol and the mass of the introduced reference component to be determined:
  2. where a is the slope of the calibration curve,
  3. x is the peak area of the analyte (standard sample),
  4. The quantitative content of glycidol in an oil sample is calculated using the formula:
  5. where X is the concentration of glycidol in the test sample, mg/kg;
  6. A - peak area of glycidol;
  7. - tangent of the slope of the calibration curve;
  8. W – mass of the test sample, g;
  9. 0.48 is the conversion factor for the mass of 3-MBPD to glycidol.

Description

The invention relates to the oil and fat industry, in particular to methods for the quantitative and qualitative determination of the content of glycidol and its esters in lipid-containing food matrices, and can be used to determine glycidol in liquid and solid vegetable oils. The analysis of glycidol in fat-and-oil products, whether using direct methods (HPLC-MS, GC-MS) or indirect methods (GC-MS), is a complex analytical task. This is due to the need for high-tech and expensive equipment (chromatographs, mass spectrometers), as well as the need for highly specialized engineering personnel to operate and maintain this equipment. Thus, the key indirect method, based on the hydrolysis of glycidol esters followed by derivatization and chromatography, requires not only complex multi-stage sample preparation, but also the availability of appropriate instrumentation and highly qualified specialists in the laboratory, which creates a high entry barrier for conducting such studies. The prototype of the invention is GOST 34900-2022 "Animal and vegetable fats and oils. Determination of the content of 2-monochloropropanediol and fatty acid esters of 2-monochloropropanediol, 3-monochloropropanediol and fatty acid esters of 3-monochloropropanediol and glycidyl esters of fatty acids using enzymatic hydrolysis", which provides for the preparation of reference samples of the compounds to be determined by mixing internal standards with a solvent, derivatization with phenylboronic acid, extraction with hexane, concentration, followed by analysis of reference samples by gas chromatography with a mass detector, construction on the basis of the obtained data of a calibration dependence and a regression equation for each component to be determined relative to the internal standard, preparation of the test sample by mixing the oil sample with a solvent, enzymatic hydrolysis of the mixture with a solution of Candida rugosa lipase, followed by heating the mixture at 80 ° C for 10 minutes, followed by cooling with running water to a temperature of 20-25°C and purification from free fatty acids with hexane, derivatization with a 2.5% solution of phenylboric acid, extraction of phenylboron derivatives of the components being determined with hexane, concentration in a stream of nitrogen, analysis of the test sample on a gas chromatograph with a mass-selective detector, calculation of the content of each component being determined in the test sample is carried out according to a previously compiled equation describing the calibration line, constructed in the coordinates of the ratio of the value of the peak areas of the reference components being determined to the values of the peak areas of the internal standard and the ratio of the mass of the introduced standard components being determined to the mass of the introduced internal standard: where a is the slope of the calibration curve; x - peak area; b - the intersection point of the calibration curve with the Y axis. The quantitative content of glycidol in an oil sample is calculated using the formula: where X is the concentration of the compound being determined in the test sample, mg/kg; A - peak area of the phenylboron derivative quantitative ion of the compound being determined; Авс – peak area of the internal standard; a - tangent of the slope of the calibration curve; b - the point of intersection of the calibration curve with the Y axis; IS – the amount of internal standard introduced into the test sample, μg; W is the mass of the test sample, g. The objective of the invention is to improve the method for determining glycidol in vegetable oils. The technical result of the invention is an expansion of the arsenal of methods for determining glycidol, providing the possibility of determining glycidol in vegetable oils while maintaining high accuracy and speed of analysis when implementing this method. The technical result is achieved in that the method for determining the qualitative and quantitative composition of glycidol in vegetable oil includes the preparation of reference samples of the compound being determined, followed by analysis of the reference samples on a gas chromatograph - construction on the basis of the obtained data of a calibration dependence and a regression equation for glycidol, preparation of the test sample, analysis of the test sample, calculation of the content of the compound being determined in the test sample, wherein the preparation of reference samples in unrefined oil and the test sample is carried out by mixing the reference samples and the test sample, respectively, with a solvent, subsequent enzymatic hydrolysis of the samples with a solution of Candida rugosa lipase, heating them at a temperature of 80 ° C for 10 minutes, purification from free fatty acids with hexane, extraction of 3-MBPD with a mixture of diethyl ether - ethyl acetate in a ratio of 3: 2, evaporation in a stream of nitrogen, derivatization of 3-MBPD with pentafluoropropionic