Determination of 18 sulfonamide residues in puffer fish and eels by liquid chromatography-tandem mass spectrometry (1)

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1 Scope of application

Used for 18 kinds of sulfa ( sulfadiazine , sulfathiazole , sulfapyridine , carbaminomethyl pyrimidine, sulfa-6-methoxypyrimidine , carbamide thiadiazole , sulfamethazine , sulfamethazine) in puffer fish and grade fish Oxypyridazine, sulfa-p-methoxypyrimidine , carbamidochloropyridazine, sulfamethoxazole, carbamine o-dimethoxazole, carbamidodimethylisoxazole, sulfafenac, sulfachloropyrazine, sulfamethoxazole Determination of residual amounts of phenpyrazole, sulfadimethoxine , sulfaquinoxaline ) by liquid chromatography-tandem mass spectrometry
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2 Principle of the method

Sulfonamide residues in puffer fish and eels were extracted with acetonitrile and centrifuged.
The supernatant was dehydrated by anhydrous sodium sulfate and blown to near dryness with a nitrogen concentrator.
The residue was dissolved in acetonitrile-0.
01mo/L ammonium acetate solution, and n-hexane After degreasing and passing through a 0.
2um filter membrane, the sample solution is measured by a liquid chromatography-tandem mass spectrometer and quantified by an internal standard method
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3 Reagents and materials

Methanol, acetonitrile, formic acid, n-hexane: chromatographically pure; ammonium acetate: superior grade; anhydrous sodium sulfate: analytically pure, burned at 650°C for 4 hours, and placed in a desiccator for later use
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0.
01mol/L ammonium acetate solution: Weigh 0.
77g of ammonium acetate and dissolve it in 1000mL of water
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Constant volume solution: Acetonitrile-0.
01mol/L ammonium acetate solution (3+22, v/v), measure 12mL acetonitrile and 88mL ammonium acetate solution and mix evenly; 0.
1% formic acid solution: absorb 1.
0mL formic acid and dilute with water to 1000mL
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18 kinds of sulfonamide standard materials: purity ≥99%
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0.
1mg/mL standard stock solution: accurately weigh an appropriate amount of each sulfonamide standard substance, and use methanol to prepare a 0.
1mg/mL standard stock solution.
The solution is stored at 4°C
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5.
0ug/mL sulfonamide mixed standard working solution: Pipette 0.
5mL of each standard stock solution into a 10mL volumetric flask, dilute to the mark with methanol, and prepare a 5.
0ug/mL mixed standard working solution
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Sulfa internal standard substances: sulfamethoxazole-D4, sulfadiazine-D4, sulfathiazole-D4
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5.
0ug/mL Sulfamethoxazole-D4, Carbamazepine-D4, Sulfathiazole-D4 internal standard stock solution: Weigh appropriate amount of Sulfamethoxazole-D4, Phospamine-D4, Sulfathiazole- The D4 standard substance was made up to 0.
1mg/mL with methanol, and the solution was stored at 4°C
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Sulfonamide mixed internal standard working solution: draw 0.
5 mL of sulfamethoxazole-D4, sulfadiazine-D4, and sulfathiazole-D4 stock solutions to a 10 mL volumetric flask, dilute to the mark with methanol, and prepare a concentration of 5ug/ mL mixed internal standard working solution
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Matrix standard working solution: draw different volumes of mixed standard working solution and 4uL mixed internal standard working solution, and use blank sample extract to make 5.
0ng/mL, 10.
0ng/mL, 20.
0ng/mL, 50.
0ng/mL, 100.
0ng/ mL of matrix standard working solutions of different concentrations
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4 Instruments and equipment

Liquid chromatography-tandem mass spectrometer; equipped with electrospray ion source
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5 Sample pretreatment

(1) Sample preparation

Take out a representative sample of about 1 kg from all the samples, fully mash, mix, and divide them into two parts, and put them into clean containers
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(2) Extraction and purification

Weigh 10g sample, accurate to 0.
01g
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Prepare the sample blank extract according to the above steps
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