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GB 31659.6-2022: (National food safety standards-Determination of cloprostinol residues in milk by liquid chromatography-tandem mass spectrometry)
Status: Valid
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(National food safety standards-Determination of cloprostinol residues in milk by liquid chromatography-tandem mass spectrometry)
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GB 31659.6-2022
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Standard similar to GB 31659.6-2022 GB 31659.2 GB 31659.3 GB 31659.15 Basic data | Standard ID | GB 31659.6-2022 (GB31659.6-2022) | | Description (Translated English) | (National food safety standards-Determination of cloprostinol residues in milk by liquid chromatography-tandem mass spectrometry) | | Sector / Industry | National Standard | | Word Count Estimation | 9,990 | | 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 31659.6-2022: (National food safety standards-Determination of cloprostinol residues in milk by liquid chromatography-tandem mass spectrometry)
---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
National Health Commission of the People's Republic of China
National Food Safety Standards
Determination of Cloprostinol Residues in Milk
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 cloprostinol residues in milk 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 cloprostinol residues in milk.
This document applies to the detection of cloprostinol residues in 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 cloprostinol in the sample was extracted with acetonitrile, purified by mixed anion-exchange solid-phase extraction column, liquid chromatography-tandem mass spectrometry negative ion mode
determined by formula and quantified by external standard method.
5 Reagents and materials
The reagents used in the following are all analytical reagents unless otherwise specified; the water is the first-class water in accordance with the provisions of GB/T 6682.
5.1 Reagents
5.1.1 Acetonitrile (CH3CN). chromatographically pure.
5.1.2 Ammonia (NH3.H2O).
5.1.3 Formic acid (CH2O2).
5.1.4 Anhydrous sodium sulfate (Na2SO4).
5.1.5 Ammonium acetate (CH3COONH4). chromatographically pure.
5.2 Standards
5.2.1 Cloprostenol (C22H29ClO6, CAS number. 40665-92-7), content ≥ 98%.
5.3 Solution preparation
5.3.11 0.1% formic acid solution. take 1mL of formic acid, dilute it with water to 1000mL, and mix well.
5.3.2 5% ammonia solution. take 50mL of ammonia water, dilute to 1000mL with water, and mix well.
5.3.3 2% formic acid in acetonitrile solution. take 20mL of formic acid, dilute to 1000mL with acetonitrile, and mix well.
5.3.4 0.1mol/L ammonium acetate solution. Weigh 7.70g of ammonium acetate, dissolve in water and dilute to 1000mL, mix well.
5.3.5 5mmol/L ammonium acetate solution. take 50mL of 0.1mol/L ammonium acetate solution, dilute with water to 1000mL, and mix well.
5.3.6 Acetonitrile ammonium acetate solution. Take 30mL of acetonitrile, add 5mmol/L ammonium acetate solution to 100mL, mix well.
5.4 Preparation of standard solution
5.4.1 Standard stock solution. take about 10 mg of cloprostenol sodium reference substance, weigh it accurately, add an appropriate amount of acetonitrile to dissolve and dilute to 10 mL
A volumetric flask was prepared to make a standard stock solution of cloprostinol with a concentration of 1 mg/mL. It was stored below -18 ℃ and the validity period was 3 months.
5.4.2 Standard intermediate solution. Accurately measure 0.1mL of standard stock solution, put it in a 10mL volumetric flask, dilute it to the mark with acetonitrile, and prepare a concentration of
10 μg/mL standard intermediate solution. Store at 2°C~8°C, valid for 1 month.
5.4.3 series standard working solution. Accurately measure an appropriate amount of standard intermediate solution, dilute it with ammonium acetate and acetonitrile to prepare a concentration of 5ng/mL,
A series of standard working solutions of 10ng/mL, 20ng/mL, 50ng/mL, 100ng/mL, and 500ng/mL. Ready to use.
5.5 Materials
5.5.1 Mixed anion exchange solid phase extraction column. 60mg/3mL or its equivalent.
5.5.2 Membrane. 0.22 μm, organic phase.
5.5.3 Centrifuge tube. 10mL, 50mL.
6 Instruments and equipment
6.1 High performance liquid chromatography-tandem mass spectrometer. equipped with electrospray ionization source (ESI).
6.2 Analytical balance. Sensitivity 0.01g and 0.00001g.
6.3 Vortex mixer.
6.4 Ultrasound machine.
6.5 Refrigerated centrifuge.
6.6 Nitrogen blowing instrument.
6.7 Solid phase extraction device.
7 Preparation and storage of samples
7.1 Preparation of samples
Take an appropriate amount of fresh or thawed blank or test sample, and homogenize.
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 standard working solution of appropriate concentration, and add the sample as a blank.
7.2 Storage of samples
Store below -18°C.
8 Measurement steps
8.1 Extraction
Take 2 g of the test material (accurate to ±0.05 g) in a 50 mL centrifuge tube, add 5 mL of acetonitrile, 2 g of anhydrous sodium sulfate, vortex and mix, and ultrasonically extract
10 min, centrifuged at 10000 r/min at 4 °C for 10 min, the supernatant was taken into a 10 mL centrifuge tube, the extraction was repeated once, and the supernatant was combined twice.
Blow dry at 40°C with nitrogen, dissolve the residue in 1 mL of acetonitrile, add 3 mL of 0.1% formic acid aqueous solution, vortex and mix well, and set aside.
8.2 Purification
Take a mixed anion-exchange solid-phase extraction column, activate it with 3 mL of acetonitrile, and equilibrate with 3 mL of water. Take the spare liquid to pass through the column, and use 5% ammonia solution to
Rinse with 3mL and drain. Elute with 3mL of 2% formic acid acetonitrile solution, collect the eluent, blow dry with nitrogen at 40°C, and wash the residue with 1mL of acetonitrile acetic acid
Ammonium solution was dissolved, filtered with a microporous membrane, and determined by liquid chromatography-tandem mass spectrometry.
8.3 Preparation of matrix-matched standard curve
Accurately measure 1mL each of the standard working solution of cloprostinol, dissolve the residues of the blank sample after extraction, purification and drying, respectively, and filter through the filter membrane.
filtered, and prepared into a series of bases with concentrations of 5 ng/mL, 10 ng/mL, 20 ng/mL, 50 ng/mL, 100 ng/mL and 500 ng/mL.
Mass matching standard solution for liquid chromatography-tandem mass spectrometry determination, with the characteristic ion mass chromatographic peak area as the ordinate, the corresponding standard solution concentration
As the abscissa, draw a standard curve. Find the regression equation and correlation coefficient.
8.4 Determination
8.4.1 Chromatographic conditions reference conditions
a) Chromatographic column. C18 column with a length of 150 mm, an inner diameter of 2.1 mm, and a particle size of 5 μm, or those with equivalent performance;
b) Mobile phase. A is 5mmol/L ammonium acetate solution; B is acetonitrile;
c) Flow rate. 0.3mL/min;
d) Injection volume. 5 μL;
e) Column temperature. 30°C;
f) Mobile phase gradient and elution program are shown in Table 1.
8.4.2 Reference conditions for mass spectrometry
a) Ion source. electrospray ion source, negative ion mode;
b) Detection method. multiple reaction monitoring (MRM);
c) Sheath gas pressure (GS1). 344.75kPa (50psi);
d) Auxiliary air pressure (GS2). 344.75kPa (50psi);
e) Collision gas pressure (colision gas). 34.475kPa (5psi);
f) curtain gas pressure (curtaingas). 206.85kPa (30psi);
g) Negative ion mode electrospray voltage (IS). -4500V;
h) Atomization temperature. 500°C;
i) The sheath gas, auxiliary gas, and collision gas are all high-purity nitrogen. Parameters such as spray voltage and collision energy should be optimized to optimal sensitivity;
j) The monitored ion parameters are shown in Table 2.
8.4.3 Assay
Take the sample solution and matrix-matched standard solution, set the instrument conditions according to 8.4.1 and 8.4.2, and perform single-point or multi-point calibration. External standard method
Calculation. The characteristic ion mass chromatographic peak area of the target drug in the matrix matching standard solution and the test solution should be within the linear range of the instrument detection.
Within the range. The ratio of the retention time of the substance to be tested in the sample solution to the retention time of the substance to be tested in the matrix matching standard working solution, the deviation is within ±
2.5%, and the relative abundance of ions in the sample solution is compared with the relative abundance of ions in the matrix-matched standard solution, which meets the requirements of Table 3.
Then it can be judged that the corresponding substance to be tested exists in the sample. See Appendix A for the relevant spectrum.
8.5 Blank test
Take the blank sample, except that no drug is added, the same measurement steps are used for parallel operation.
9 Calculation and presentation of results
The residual amount of cloprostinol 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 1.5 μg/kg, and the limit of quantification was 5 μg/kg.
10.2 Accuracy
The recovery rate of this method was 80%-120% at the level of spiked concentration of 5 μg/kg-500 μg/kg.
10.3 Precision
The intra-assay relative standard deviation of this method was ≤15%, and the inter-assay relative standard deviation was ≤15%.
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