GB 1886.349-2021National food safety standard - Food additives - Five carbon diacetal (also known as glutaraldehyde) (English PDF)

1 Scope

This Standard applies to the food additive five-carbon diacetal (also known as glutaraldehyde) obtained by that vinyl methyl ether or vinyl ethyl ether reacts with acrolein to form 2-alkoxy-3,4-dihydropyran, which is then hydrolyzed.

2 Chemical name, molecular formula, structural

formula and relative molecular mass

3 Technical requirements

Annex A Inspection methods

WARNING: Some reagents used in the inspection methods of this Standard are toxic or corrosive. Operate in accordance with relevant national regulations. Please be careful when using them. If it is splashed on the skin, rinse immediately with water. In severe cases, seek medical attention immediately. When using volatile acids, it shall be carried out in a fume hood.

A.1 General The reagents and water used in this Standard refer to analytically-pure reagents and grade 3 water specified in GB/T 6682 when other requirements are not indicated. The standard titration solution, standard solution for impurity determination, preparations and products used in the test are prepared in accordance with GB/T 601, GB/T 602 and GB/T 603 when other requirements are not indicated. The solution used in the test refers to an aqueous solution when it is not specified which solvent is used to prepare it.

A.2 Identification test A.2.1 Solubility Pipette about 1mL of specimen into a beaker. Add 1mLof water. Shake not less than 30s. Observe the dissolution of the sample within 5min. The specimen shall be easily dissolved in water.

A.2.2 Identification of the melting point of 2,4-dinitrophenylhydrazone A.2.2.1 Method principle Five carbon diacetal reacts with 2,4-dinitrophenylhydrazine to form 2,4-dinitrophenylhydrazone precipitation. 2,4-dinitrophenylhydrazone has a specific melting point.

A.2.2.2 Reagents and materials A.2.2.2.1 2,4-dinitrophenylhydrazine solution: Take 0.8g of 2,4-dinitrophenylhydrazine. Add 4mL of sulfuric acid. Stir until it is completely dissolved. Continue stirring. Add 6mL of water along with the wall in drops. Add 20mL of ethanol. Mix and shake well. Filter. Take the filtrate.

A.2.2.2.2 Absolute ethanol.

The carbonyl group of glutaraldehyde can react with hydroxylamine hydrochloride to produce glutaric oxime. Glutaraldehyde will release hydrochloric acid while generating glutaric oxime. Triethanolamine is weakly alkaline. It can neutralize and remove hydrochloric acid. Add excessive triethanolamine. Use hydrochloric acid standard solution to backdrop. The content of glutaraldehyde can be calculated by calibrating the blank determination at the same time.

A.3.2 Reagents and materials A.3.2.1 Triethanolamine solution: 74g/L. Dissolve 74g of triethanolamine with a certain amount of water and transfer to a 1L volumetric flask. Use water to set volume to the scale and mix well.

A.3.2.2 Hydroxylamine hydrochloride solution: 35g/L, pH is 3.60. Use a certain amount of water to dissolve 35.0g of hydroxylamine hydrochloride. Transfer to a 1L volumetric flask. Use water to set volume to the scale. Mix well. Use triethanolamine solution to adjust pH to 3.60.

A.3.2.3 Hydrochloric acid standard titration solution: c(HCl)=0.5mol/L.

A.3.3 Instruments and equipment A.3.3.1 Electronic balance: the resolution is 0.1g and 0.0001g.

A.3.3.2 Magnetic stirrer.

A.3.3.3 Acidity meter: the accuracy is +/-0.01.

A.3.4 Determination method Add 65.0mL of pH 3.60 hydroxylamine hydrochloride solution and 30.8mL of triethanolamine solution into a 200mL small beaker. Put a Teflon (or equivalent material) rotor in each small beaker. Place the small beaker on a magnetic stirrer and stir. Accurately add a certain amount of sample (approximately equivalent to 300mg of five carbon bisacetal). Put a lid and stir. Stir at room temperature for at least 60min, but not more than 90min. At the same time, do a reagent blank test without adding a specimen. After the stirring is over, use 0.5mol/L hydrochloric acid to titrate the specimen and the blank sample to pH