Recently, it was reported that the food sold by the well-known American fast food giant Subway in North America contains a substance called "azodicarbonamide"（Azodicarbonamide）The chemical product, which is commonly used as a raw material for rubber shoe soles and yoga mats, has been present in the food ingredients of Subway for at least one year. It is understood that besides Subway, the vast majority of bread sold in Starbucks, McDonald's, Burger King, and supermarkets contains this ingredient. Afterwards, multiple foreign fast food chain brands were affected by the stray bullets and involved in the * * questioning of the presence of foaming agents. Jiang Yumei, "Deputy Director of the Food and Drug Administration of the Ministry of Health and Welfare" in Taiwan, China, China, said in an interview with the media that some businesses would choose to add azoformamide in order to make flour sell well and taste good. Azodicarbonamide has oxidation and bleaching effects, and is usually added to flour as a gluten enhancer to enhance the elasticity and toughness of gluten. It can also be used as a rapid fermentation agent for baked goods.

Currently, the United Nations Codex Alimentarius Commission(Codex)and the united statesFDAIt is listed as a legal food additive, but the European Union and Australia prohibit the use of this chemical substance as it may cause respiratory diseases and allergies. And according toFDAThe limit is that the content of azodicarbonamide per kilogram of bread shall not exceed45Milligrams will not affect physical health. At present, our countryGB2760Hygiene Standards for the Use of Food Additives(contain1997～2006Annual supplementary varieties)Regulations on wheat flourADA**The usage amount is0.045g/kgAlthough China has stipulated the usage amount of azoformamide in flour, there is currently no information on its use in flourADAThere are no reports on rapid detection methods and no relevant detection standards. Our company has establishedLC-3000Analysis Scheme for Azoformamide Detection in Flour by Liquid ChromatographyThe analysis method is simple in pre-processing, highly sensitive, and can be widely used in flourADAThe testing.

1、 Instruments and reagents

Lu ChuangLC-3000Type effective liquid chromatography instrument, equipped with automatic sampler and diode array detector(DAD); oscillator(SA400Type, JapanYamatocompany)Centrifuge(Universal 32Type, GermanyHettichcompany)Vortex mixer(M37610-33Type, United StatesBarnsteadcompany)Blowing nitrogen concentrator(NC-2012Type, Luchuang Analytical Instrument Co., Ltd).

The water is deionized water; Acetonitrile and dimethylformamide are chromatographically pure; Acetone and n-hexane are analytical grade; filter membrane(0.20μm, aqueous phase)Azoformamide standard(Purity greater than99.0%)Purchased from the United StatesChemserviceThe company.

2、 Standard solution preparation

Accurately weigh an appropriate amount of standard substance, dissolve it in dimethylformamide and dilute to volume, and prepare it into1000mg/LStandard stock solution, packaged in liquid phase vials, in-80Store in a refrigerator at ℃,2Use within the week. Use as needed20mmol/LPrepare standard working solution of ammonium acetate aqueous solution.

3、 Sample processing method

Weigh flour1g(**Go to0.001g)a surname50mLIn the plastic centrifuge tube, add10mLAcetone, extraction by shaking at room temperature15min，5000r/mincentrifuge5min. Take the upper layer5mLAcetone in40Blow nitrogen to near dryness at ℃, then use20mmol/LDilute the aqueous solution of ammonium acetate to a certain volume1mLJoin again1mLN-hexane, vortex oscillation. Let it stand and separate into layers, take the lower aqueous solution and filter it through a membrane, and immediately perform liquid phase analysis.

4、 Liquid chromatography conditions

Chromatographic column:Nucleosil100-5CN，250mm×416mm(i.d.)，5μmColumn temperature:25℃； Current Speed:0.8mL/minEquivalency elution:20mmol/LAmmonium acetate aqueous solution-acetonitrile(By volume80∶20)Detection wavelength:245nmInjection volume:10μL.

The liquid chromatography analysis scheme for detecting azoformamide in this flour is widely usedApplied to: various flour mills, food companies, instant noodle companies, food and drug supervision, quality supervision, etc.

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1All products of the company have undergone strict factory inspections, and all technical indicators meet the requirements of relevant national standards. The product is installed and debugged by technical service engineers or provided with free telephone guidance.
2After the product installation and acceptance are qualified, during the one-year warranty period, except for human damage factors, our company guarantees free maintenance and lifelong maintenance of the equipment; We only charge a cost fee for vulnerable parts and provide free technical support and discounted accessory supply.
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