Determination of 22 sulfonamide residues in foods of animal origin

Summary

Sulfonamides (SAs) is a general term for a class of drugs with the structure of p-aminobenzenesulfonamide. They are widely used as chemotherapeutic drugs for the prevention and treatment of bacterial infectious. Source: Food Safety Monitoring Technology (Chemical Industry Press)

Operation method

HPLC-UV method

Materials and Instruments

Animal Liver Kidney Muscle Fish Milk
n-propanol acetonitrile n-hexane
Brown centrifuge bottle Brown dispensing funnel Rotary evaporator Glass mortar Chromatography columns

Move

1. Pre-processing

(1) Liquid-liquid extraction and purification method

Animal liver, kidney, muscle, aquatic products: weigh 5 g of sample, accurate to 0.01 g. Place in a 50 mL brown centrifuge bottle, add 25 mL of acetonitrile and anhydrous sodium sulfate, mix rapidly in a liquid mixer for 1 min, homogenize and centrifuge at 3000 r/min for 5 min, transfer the acetonitrile layer into a 100 mL brown separatory funnel. The precipitate after centrifugation was then added with 25 mL of acetonitrile and shaken well, centrifuged at 3000 r/min for 5 min, and the acetonitrile extracts were combined.

Milk: Weigh 5 g of sample, accurate to 0.01 g. Place in a 50 mL brown centrifuge bottle, add 25 mL acetonitrile, vortex mixing for l min, ultrasonic extraction for 30 s, centrifugation at 3000 r/min for 10 min, filter, and wait for purification.

Add 25 mL of acetonitrile saturated n-hexane solution into the extract, shake for 5 min, transfer the bottom layer of acetonitrile solution into a 100 mL brown chicken-centered bottle, add 10 mL of n-propanol, and evaporate with rotary evaporator at 45 ℃ in a water bath under reduced pressure until nearly dry, and then blow-dry under nitrogen flow. Add 1.00 mL of acetonitrile-water solution (1 + 1) to the residue, sonicate for 30 s to dissolve the residue, transfer the dissolved solution into a 10 mL brown centrifuge tube, add 0.5 mL of acetonitrile saturated with n-hexane, centrifuged at 3000 r/min for 5 min, discard the n-hexane solution, and transfer the bottom layer of acetonitrile-water solution into a brown sample vial for liquid chromatographic determination.

(2) Solid-phase dispersion microwave-assisted extraction method

Animal liver, kidney, muscle, aquatic products: weigh 6 g of C18 filler in a glass mortar, take 2.0 g of animal tissue and add it to the C18 filler with a glass pestle and mortar gently ground for 30 s, so that the sample and the filler were evenly mixed; mounted in a 50 mL PTFE tube, add 25 mL of acetonitrile/water, vortex shaking for 1 min into the home microwave oven microwave Fukushima 30 s, centrifugation for 5 min, the acetonitrile layer was transferred to a 100 mL bottle of acetonitrile water. The acetonitrile layer was transferred into a 100 mL brown dispensing funnel. After centrifugation, the precipitate was added with 25 mL of acetonitrile and shaken well, then extracted by ultrasonic waves for 30 s, centrifuged at 3000 r/min for 5 min, and the acetonitrile extracts were combined.

Milk: take 2.0 g of milk, put it in a glass mortar, add 6 g of diatomaceous earth, add 6 g of C18 filler, gently grind it with a glass pestle and mortar for 30 s, so that the sample and the filler were uniformly mixed; put it in a 50 mL PTFE tube, add 25 mL of acetonitrile-water solution (1 + 1), vortex and shake it for 1 min, put it into a domestic microwave oven for 30 s, centrifuge it for 5 min, and then combine the acetonitrile layer with the extract. The acetonitrile layer was transferred into a 100 mL brown dispensing funnel. After centrifugation, the precipitate was added with 25 mL of acetonitrile and shaken well, then extracted by ultrasonic waves for 30 s, centrifuged at 3000 r/min for 5 min, and the acetonitrile extracts were combined.

Add 25 mL of acetonitrile saturated n-hexane solution to the extract, shake for 5 min, transfer the bottom layer of acetonitrile solution into a 100 mL brown chicken-centered flask, add 10 mL of n-propanol, and evaporate under reduced pressure with a rotary evaporator in a water bath at 45 ℃ until nearly dry, and blow-dry with a stream of nitrogen. To the residue, 1.0 mL acetonitrile-water solution (1 + 1) was added, and the residue was dissolved by sonication for 30 s. The dissolved solution was transferred into a 10 mL brown centrifuge tube, and 0.5 mL acetonitrile-saturated n-hexane was added, and centrifuged at 3000 r/min for 5 min. The n-hexane solution was discarded, and the bottom layer of the aqueous acetonitrile solution was transferred into a brown sample vial for the determination of the liquid chromatography.

2. Instrumental parameters

Column: Aglient ZORBAX SB-C18, 5 um, 250 mm × 4.6 mm;

Flow rate: 0.8 mL/min;

Column temperature: 30 ℃;

Injection volume: 30 uL;

Determination wavelength: 260 nm, 275 nm, 280 nm;

Mobile phase: acetonitrile with 15% methanol-0.1% formic acid solution.


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Categories: Protocols