Search

CN-121994955-A - Method and system for separating and measuring residual quantity of penconazole enantiomer in rice by adopting ultra-high performance phase-combining chromatography

CN121994955ACN 121994955 ACN121994955 ACN 121994955ACN-121994955-A

Abstract

The invention relates to the technical field of pesticide residue detection, in particular to a method and a system for separating and measuring the enantiomer residue of penconazole in rice by adopting an ultra-high performance synthetic phase chromatography. According to the invention, through optimizing the sample extraction and solid phase extraction purification process and combining the chiral separation condition of the ultra-efficient phase-combining chromatograph by taking supercritical carbon dioxide as a main mobile phase, the rapid and effective separation of two enantiomers and the accurate and sensitive quantification under PDA detection are realized, so that the matrix interference is reduced, the analysis efficiency and the result reliability are improved, and the application requirements of monitoring and supervising the residual enantiomer of the penconazole in rice are met.

Inventors

  • ZHANG WENHUA
  • PAN LIRONG
  • ZHAO ZIYAN
  • SHAO YU
  • XU DUNMING
  • WU YUAN

Assignees

  • 杭州海关技术中心
  • 厦门海关技术中心

Dates

Publication Date
20260508
Application Date
20260205

Claims (10)

  1. 1. A method for separating and measuring the residual quantity of the enantiomer of the penoxsulam in rice by adopting an ultra-efficient phase-combination chromatography, which is characterized by comprising the following steps: S1, extracting, namely weighing a rice sample, taking acetonitrile as an extracting agent, adding sodium chloride for salting-out extraction, centrifuging, and taking supernatant; S2, purifying, namely loading the solution to be purified to a hydrophilic-lipophilic balance type solid phase extraction column activated by methanol and water, eluting the solution with methanol to water=3:7 (v/v) and discarding effluent liquid when the solution surface is dry, eluting the solution with 1% ammonia water methanol solution and collecting eluent, concentrating the eluent to be nearly dry at 40 ℃, and dissolving the eluent with n-heptane to isopropanol=7:3 (v/v) to fix the volume and filtering to obtain the upper solution; S3, ultra-efficient phase-combining chromatographic separation and detection, namely injecting the upper solution into an ultra-efficient phase-combining chromatographic system, and performing gradient elution under the conditions of 35 ℃ and 17.2 MPa backpressure by taking a chiral chromatographic column as a filler and taking supercritical carbon dioxide as a mobile phase A and methanol as a modifier mobile phase B; the volume fraction of the modifier B in the gradient elution is changed between 15% and 25%, the flow rate is 1.0 mL/min, the sample injection amount is 5.0 mu L, and the gradient elution program is as follows: 15% B for 0-0.7 min, 15 for 0.7-1.2 min 20% to 20% of B, 1.2 to 1.6 min of 20% of B, and 1.6 to 2.2; the min is 20% -25% B, and the min is 2.2-4.0 min 25% of B, wherein 25%B~15%B;5.0~7.0 min is 15% of B in 4.0-5.0 min; the method comprises the steps of separating two enantiomers of the penconazole, detecting at 230 nm by adopting a diode array detector, and quantifying the two enantiomers respectively by adopting an external standard method.
  2. 2. The method according to claim 1, wherein the sample amount in the extraction step is 5 g, the acetonitrile addition amount is 20mL each time, and the extracts are combined after two extractions.
  3. 3. The method according to claim 1, wherein the sodium chloride addition amount in the salting-out extraction is 3 g, the extraction shaking time is 20 min, and the centrifugation conditions are 4000 r/min and 5 min.
  4. 4. The method according to claim 1, wherein the solution to be purified is obtained by rotary evaporation and concentration of the combined extracts to near dryness followed by reconstitution with 5mL acetonitrile.
  5. 5. The method of claim 1, wherein the solid phase extraction column is an HLB solid phase extraction column, the packing amount is 500 mg, the column volume is 6 mL, and the activation method is to sequentially add 5 mL methanol and 5 mL water.
  6. 6. The method of claim 1, wherein the eluent volume is 5 mL and the eluent volume is 5 mL.
  7. 7. The method according to claim 1, wherein the constant volume is 1 mL, and the filtration is carried out after the filtration by an organic phase microporous filter membrane.
  8. 8. The method of claim 1, wherein the chiral chromatography column is a 150 mm x 3.0 mm, 2.5 μm specification chiral chromatography column.
  9. 9. The method of claim 1, wherein the external standard is quantitatively established using a mixed standard working solution of two enantiomers.
  10. 10. An ultra-high performance co-phase chromatographic separation assay system for carrying out the method of any one of claims 1-9, comprising: the sample pretreatment module at least comprises an extraction container, a mixing/oscillating device, a centrifugal device and a concentration device; The solid phase extraction purification module at least comprises a solid phase extraction device which can be assembled with an HLB solid phase extraction column; the ultra-efficient phase-combining chromatographic module at least comprises a supercritical carbon dioxide supply unit, a modifier supply unit, a back pressure regulating unit, a column temperature control unit and a chiral chromatographic column; the detection and data processing module at least comprises a diode array detector and a data processing unit; Wherein the data processing unit is configured to control the system to perform gradient elution with supercritical carbon dioxide as mobile phase a and methanol as modifier mobile phase B at 35 ℃ and 17.2 MPa, and to collect signals at 230 nm and perform two enantiomer quantification according to external standard method.

Description

Method and system for separating and measuring residual quantity of penconazole enantiomer in rice by adopting ultra-high performance phase-combining chromatography Technical Field The invention relates to the technical field of pesticide residue detection, in particular to a method and a system for separating and measuring the enantiomer residue of penconazole in rice by adopting an ultra-high performance synthetic phase chromatography. Background The penconazole (mefentrifluconazole, MFZ for short) is an isopropanol triazole fungicide, has the characteristics of broad spectrum, high efficiency, systemic conductivity and the like, and has important application value in crop disease control of grains and the like. With the popularization and use of the bactericides in agricultural production, the residual risks in agricultural products (especially rice serving as one of main grains) and the food safety supervision demands brought by the bactericides are increasingly prominent. Therefore, the establishment of a reliable detection method for MFZ residues in complex matrixes such as rice and the like has important significance for agricultural product quality safety monitoring, risk assessment and supervision law enforcement. At present, conventional analysis methods for triazole bactericides in the field of pesticide residue detection mainly comprise a Gas Chromatography (GC) or Liquid Chromatography (LC) and mass spectrometry (MS/MS) combined method, a High Performance Liquid Chromatography (HPLC)/Ultra High Performance Liquid Chromatography (UHPLC) combined ultraviolet or diode array detector (UV/DAD/PDA) method and the like. The method is relatively mature in the aspect of quantitative analysis of the total amount of the racemate (racemate), and can meet the requirements of partial supervision scenes on detection limit, accuracy and flux. However MFZ is typical of chiral pesticides, which contain chiral carbon centers in the molecule and exist in enantiomeric form. For chiral pesticides, the two enantiomers may have differences in bioactivity, metabolism/degradation behavior, ecological toxicity and behavior in environment and food chain, and if the total racemate is only used for characterization, the real exposure level and risk characteristics of the enantiomer level may not be reflected, and the more refined risk evaluation and process control of the chiral pesticides are not facilitated. Therefore, the method has obvious scientific significance and application value for carrying out the separation and quantitative analysis of the enantiomer level of MFZ in the matrixes of foods and agricultural products. In terms of enantiomer analysis technical routes, traditional chiral analysis is mostly dependent on chiral chromatographic columns (e.g. polysaccharide derivative stationary phases) for normal or reverse phase liquid chromatographic separation and detection in combination with DAD/PDA or MS. Although this route is more general, for compound systems with similar structures, strong hydrophobicity or multiple co-elution interferences, conventional LC separations may suffer from longer analysis times, large solvent consumption, significant separation and peak shape stability affected by the matrix, etc. In particular, rice samples belong to complex matrixes with high starch and relative dry basis and various co-extracts, and after being extracted by organic solvents such as acetonitrile and the like, the rice samples still often contain a certain amount of lipid, pigment, surfactant and other matrix components, and the phenomena of baseline fluctuation of a chromatographic system, increased interference peaks, accelerated pollution of a chromatographic column, reduced quantitative accuracy and the like are easily caused. The above-mentioned problem of matrix interference is more pronounced with DAD/PDA systems that rely on uv absorbance signals for detection, on the one hand, the lack of selectivity information such as mass spectra for uv detection and on the other hand, co-eluting impurities are more likely to affect integration and quantification. Therefore, the enantiomer residue detection method for rice matrixes is required to have strong chromatographic separation capability, and besides, a sample purification strategy and an on-machine solvent system are required to be capable of effectively reducing interference and guaranteeing stable peak shape and response. In recent years, ultra-high performance co-phase chromatography (also commonly called ultra-high performance supercritical fluid chromatography or UPC 2/SFC) is one of the important tools for chiral separation and rapid analysis of complex systems due to its advantages of using supercritical carbon dioxide as the main mobile phase, low system viscosity, large diffusion coefficient, high column efficiency, high separation speed, relatively low organic solvent consumption, and the like. For structural analogues or enantiomer/diastereomer mixt