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GB 31659.2-2022 English PDF

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GB 31659.2-2022: (National Food Safety Standard Determination of Doxycycline Residues in Poultry Eggs, Milk and Milk Powder by Liquid Chromatography-Tandem Mass Spectrometry)
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GB 31659.2-2022English199 Add to Cart 3 days [Need to translate] (National Food Safety Standard Determination of Doxycycline Residues in Poultry Eggs, Milk and Milk Powder by Liquid Chromatography-Tandem Mass Spectrometry) Valid GB 31659.2-2022

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Basic data

Standard ID GB 31659.2-2022 (GB31659.2-2022)
Description (Translated English) (National Food Safety Standard Determination of Doxycycline Residues in Poultry Eggs, Milk and Milk Powder by Liquid Chromatography-Tandem Mass Spectrometry)
Sector / Industry National Standard
Word Count Estimation 9,996
Date of Issue 2022-09-20
Date of Implementation 2023-02-01
Issuing agency(ies) National Health Commission of the People's Republic of China, State Administration for Market Regulation

GB 31659.2-2022: (National Food Safety Standard Determination of Doxycycline Residues in Poultry Eggs, Milk and Milk Powder by Liquid Chromatography-Tandem Mass Spectrometry)


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National Health Commission of the People's Republic of China National Food Safety Standards Determination of doxycycline residues in poultry eggs, milk and milk powder Liquid Chromatography-Tandem Mass Spectrometry National Standards of People's Republic of China release State Administration for Market Regulation Ministry of Agriculture and Rural Affairs of the People's Republic of China

foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part 1.Structure and Drafting Rules for Standardization Documents" drafting. This document is published for the first time. National Food Safety Standards Determination of doxycycline residues in poultry eggs, milk and milk powder by liquid chromatography-tandem mass spectrometry

1 Scope

This document specifies the sample preparation and liquid chromatography-tandem mass spectrometry method for the detection of doxycycline residues in poultry eggs, milk and milk powder. This document is applicable to the determination of doxycycline residues in eggs, duck eggs, goose eggs, milk powder, goat milk powder, milk and goat milk.

2 Normative references

The content in the following documents constitutes the essential provisions of this document through normative references in the text. Among them, the dated reference documents, Only the version corresponding to the date applies to this document; for undated references, the latest version (including all amendments) applies to this document document. GB/T 6682 Analytical laboratory water specifications and test methods

3 Terms and Definitions

This document does not have terms and definitions that need to be defined.

4 principles

The residual doxycycline in the sample was extracted by Mclvaine-Na2EDTA buffer, purified by HLB column, and detected by liquid chromatography-tandem mass spectrometry. determined, and quantified by the external standard method.

5 Reagents and materials

5.1 Reagents Unless otherwise specified, all reagents are of analytical grade, and the water is first-class water in accordance with GB/T 6682. 5.1.1 Methanol (CH3OH). chromatographically pure. 5.1.2 Acetonitrile (CH3CN). chromatographically pure. 5.1.3 Formic acid (HCOOH). chromatographically pure. 5.1.4 Citric acid monohydrate (C6H8O7.H2O). 5.1.5 Disodium hydrogen phosphate dodecahydrate (Na2HPO4.12H2O). 5.1.6 Disodium ethylenediaminetetraacetic acid dihydrate (C10H14N2Na2O8.2H2O). 5.1.7 Sodium Hydroxide (NaOH). 5.2 Solution preparation 5.2.1 Sodium hydroxide solution (1mol/L). Take 4g of sodium hydroxide, add water to dissolve and dilute to 100mL, mix well. 5.2.2 Mclvaine-Na2EDTA buffer solution. take 12.9 g of citric acid monohydrate, 27.6 g of disodium hydrogen phosphate dodecahydrate, and 27.6 g of ethylenediaminetetraethyl dihydrate Add 900 mL of water to dissolve 37.2 g of disodium diacetate, adjust the pH to 4.0 ± 0.5 with sodium hydroxide solution, add water to dilute to 1000 mL, and mix well. 5.2.3 0.1% formic acid solution. Take 500 μL of formic acid, dilute it with water to 500 mL, and mix well. 5.2.4 5% methanol solution. Take 5mL of methanol, dilute to 100mL with water, and mix well. 5.2.5 30% methanol solution. Take 30mL of methanol, dilute to 100mL with water, and mix well. 5.3 Standards Doxycycline hydrochloride (doxycyclinehydrochloride, C22H24N2O8.HCl, CAS number. 10592-13-9), content ≥ 98.7%. 5.4 Preparation of standard solution 5.4.1 Standard stock solution. Take an appropriate amount of doxycycline hydrochloride (equivalent to 10 mg of doxycycline), weigh it accurately, add an appropriate amount of methanol to dissolve and constant volume to a 10mL volumetric flask, and prepared into a standard stock solution with a concentration of 1mg/mL. Store below -18°C, and the validity period is 1 month. 5.4.2 Standard intermediate solution Ⅰ. Accurately measure 0.1mL of standard stock solution, put it into a 10mL volumetric flask, dilute to the mark with 30% methanol, mix well, and prepare The standard intermediate solution Ⅰ with a concentration of 10 μg/mL was prepared. 5.4.3 Standard intermediate solution II. Accurately measure 1.0mL of intermediate solution I, put it in a 10mL volumetric flask, dilute it to the mark with 30% methanol, mix well, and prepare A standard intermediate solution II with a concentration of 1000ng/mL was prepared. 5.4.4 series of standard working solutions. Accurately measure 0.1mL, 0.2mL, 0.5mL, 1.0mL and 2.0mL of the standard intermediate solution II at In a 10mL volumetric flask, dilute to the mark with 30% methanol, mix well, and prepare concentrations of 10ng/mL, 20ng/mL, 50ng/mL, 100ng/mL,.200ng/mL series of standard working solutions. Ready to use. 5.5 Materials 5.5.1 Solid-phase extraction column. hydrophilic-lipophilic balanced solid-phase extraction column 60mg/3mL. 5.5.2 Microporous nylon filter membrane. 0.22 μm. 5.5.3 Qualitative rapid filter paper.

6 Instruments and equipment

6.1 Liquid chromatography-tandem mass spectrometer. with electrospray ionization source (ESI). 6.2 Analytical balance. Sensitivity 0.00001g and 0.01g. 6.3 Vortex mixer. 6.4 Vortex shaker. 6.5 High-speed refrigerated centrifuge. the speed can reach 14000r/min. 6.6 Solid phase extraction device. 6.7 Nitrogen blowing instrument.

7 Preparation and storage of samples

7.1 Preparation of samples Take an appropriate amount of fresh blank or test poultry eggs, shell them and homogenize them. Take an appropriate amount of fresh or thawed blank or test milk, and mix well. Take an appropriate amount of fresh blank or test milk powder and mix well. a) Take the homogeneous test sample as the test sample; b) Take a homogeneous blank sample as a blank sample; c) Take a homogeneous blank sample, add a standard solution of appropriate concentration, and add a sample as a blank. 7.2 Storage of samples Store poultry eggs and milk below -18°C, store milk powder at room temperature and avoid light.

8 Measurement steps

8.1 Extraction Poultry eggs and milk. Take 2g of the test material (accurate to ±0.05g), put it in a 50mL polypropylene centrifuge tube, add Mclvaine-Na2EDTA buffer 8 mL of solution, shaken for 10 min, centrifuged at 14000 r/min for 10 min at 4 °C, and absorbed the upper liquid into another 50 mL centrifuge tube. Mclvaine-Na2EDTA buffer was repeatedly extracted twice, 8 mL each time, the combined extracts were centrifuged at 14000 r/min for 10 min at 4 °C, and The supernatant is ready for use (the milk sample supernatant is filtered through filter paper for use). Milk powder. Take 2g of the test material (accurate to ±0.05g), put it in a 50mL polypropylene centrifuge tube, add Mclvaine-Na2EDTA buffer solution 10mL, shaken for 10min, centrifuged at 14000r/min at 4°C for 10min, and the supernatant was taken into another 50mL centrifuge tube. Use Mclvaine- Repeat the extraction with Na2EDTA buffer twice, 10 mL each time, combine the extracts, centrifuge at 14000 r/min at 4 °C for 10 min, and filter the supernatant Paper for later use. 8.2 Purification Take the solid-phase extraction column and activate it with 3 mL of methanol and 3 mL of water successively. Take the spare solution, pass it through the column, rinse with 3 mL of water and 3 mL of 5% methanol, and drain it. Add 3 mL of methanol to elute, pump dry, collect the eluate, blow with nitrogen at 40°C until the liquid is less than 1 mL, add 30% methanol to 1.0 mL, and vortex to mix. uniform, passed through a microporous nylon filter membrane, and was determined by liquid chromatography-tandem mass spectrometry. 8.3 Preparation of matrix-matched standard curve Accurately pipette 100 μL each of the series of standard working solutions into the blank eluent obtained through 8.1-8.2 steps, and blow nitrogen gas at 40°C until the eluent reaches the liquid level. If the volume is less than 1mL, add 30% methanol to 1.0mL, vortex and mix well, and prepare the concentration of 1.0ng/mL, 2.0ng/mL, 5.0ng/mL, A series of matrix-matched standard solutions of 10.0ng/mL and 20.0ng/mL were passed through a microporous nylon filter membrane for determination by liquid chromatography-tandem mass spectrometry. The characteristic ion mass chromatographic peak area of doxycycline is the ordinate, the concentration of the standard solution is the abscissa, and the matrix matching standard curve is drawn. 8.4 Determination 8.4.1 Reference conditions for liquid chromatography a) Chromatographic column. C18 column, column length 100mm, inner diameter 2.1mm, particle size 1.7μm, or equivalent; b) Mobile phase. A is acetonitrile, B is 0.1% formic acid solution; c) Flow rate. 0.3mL/min; d) Injection volume. 10 μL; e) Column temperature. 30°C; f) The mobile phase gradient elution program is shown in Table 1. 8.4.2 Reference conditions for mass spectrometry a) Ion source. electrospray ion source; b) Scanning mode. positive ion scanning; c) Detection method. multiple reaction ion monitoring (MRM); d) Ion source temperature. 150°C; e) Desolventization temperature. 450°C; f) Capillary voltage. 3.3kV; g) Qualitative ion pairs, quantitative ion pairs, cone voltage and collision energy are shown in Table 2. 8.4.3 Assay 8.4.3.1 Qualitative determination Under the same test conditions, the retention time of doxycycline in the sample solution matches the retention time of doxycycline in the standard working solution in the matrix The relative deviation is within ±2.5%, and the relative abundance of the detected ions should be equal to the relative abundance of the matrix matching standard solution. The allowable deviation should meet the requirements in Table 3. 8.4.3.2 Quantitative determination Take the sample solution and the matrix matching standard working solution for single-point or multi-point calibration, and quantify the peak area according to the external standard method, and the matrix matching standard work The response values of doxycycline in both the test solution and the sample solution should be within the linear range of instrument detection. Under the above chromatographic-mass See Appendix A for the characteristic ion mass chromatogram of the mass-matched standard solution. 8.5 Blank test Take the blank sample, except that no drug is added, the exact same determination steps are used for determination.

9 Calculation and presentation of results

The residual amount of doxycycline in the sample was calculated according to the standard curve or formula (1). 10 Sensitivity, accuracy and precision of detection method 10.1 Sensitivity The detection limit of this method was 1 μg/kg, and the quantification limit was 2 μg/kg. 10.2 Accuracy The recovery rate of this method was 60%-120% at the spiked concentration level of 2 μg/kg-10 μg/kg. 10.3 Precision The intra-assay relative standard deviation of this method was ≤20%, and the inter-assay relative standard deviation was ≤20%.

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