Ammonia is one of the important varieties for chemical product inspection. Ammonia inspection is one of the important links widely used in industries such as industry, agriculture, textiles, medicine, printing and dyeing, and food. Recently, the food-grade ammonia testing standard GB29201-2020 was officially released, and the "National Food Safety Standard Ammonia and Liquid Ammonia" will be officially implemented on March 11 next year. Bain engineers first learned about the inspection regulations of GB29201-2020 food-grade ammonia, especially food-grade liquid ammonia. In order to facilitate your understanding of the new standard, we will take the relevant regulations for industrial ammonia and chemical reagent ammonia inspection as examples, and make a horizontal comparison with food-grade ammonia to help you have a comprehensive understanding of ammonia inspection.

The previous version of GB29201-2020 is version 12. At that time, this version was made with reference to the American FCC standard ammonia water. GB29201-2020 maintains consistency with the items and indicators of ammonia in the previous version. However, higher standards have been proposed for the physical and chemical indicators and inspection methods of food-grade liquid ammonia. At the same time, GB29201-2020 recommends using the method specified in GB5009.75 or GB5009.12 to test the lead content in ammonia. Of course, the name of the new standard has changed accordingly, and the word liquid ammonia has been added.

The above is the general change of the new standard. So what are the regulations for food-grade ammonia in GB29201-2020? Food-grade ammonia water mainly inspects four items: ammonia content, lead content, evaporation residue, and easy oxide test. The newly added liquid ammonia inspection items mainly include 6 items of ammonia, water, oxygen, nitrogen, carbon monoxide, and hydrocarbons. The specific inspection standards are as follows:

Ammonia inspection standard.

1. The standard of ammonia content should be 27.0%~30%;

2. Lead content standard ≤0.5mg/kg;

3. The standard of evaporation residue ≤0.02%;

4. Pass the detection of easily oxidizable substances.

Liquid ammonia inspection standard

1. Ammonia content standard ≥99.9990%;

2. The moisture standard should be ≤0.0004%;

3. The oxygen content standard is less than or equal to 0.0001%;

4. The nitrogen content standard is less than or equal to 0.0003%;

5. Samples with CO content ≤0.0001%;

6. The hydrocarbon content standard is less than or equal to 0.0001%.

The above GB29201-2020 regulations and standards related to food-grade ammonia and liquid ammonia inspection. Of course, the usefulness is different, and the inspection items, inspection indicators, and inspection standards are also different. For example, the inspection standard for industrial-grade ammonia water should be HG/T5353-2018 "Industrial Ammonia Water". However, the chemical reagents using ammonia should be tested according to GB/T631-2007 "Ammonia for Chemical Reagents". As for the test items, the different uses of ammonia are different. For example, industrial ammonia only needs to test ammonia concentration, color and evaporation residue. In addition to these three reagents, ammonia can also test chloride, sulfide, sulfate, carbonate, phosphate, sodium, magnesium, potassium, iron, copper, lead, reduced potassium permanganate, etc.

In addition to the different inspection items, according to the data of the index standards, the inspection standards for the different uses of ammonia are also different. For example, ammonia concentration is one of the most important indicators of ammonia quality. Food grade ammonia concentration should be between 27.0% and 30%, industrial grade ammonia concentration should be ≥20.0%, and chemical reagent ammonia concentration should be between 25.0% and 28.0%. between. The liquid ammonia concentration standard is more stringent, reaching ≥99.9990%. Therefore, it can be seen from the above that the ammonia inspection must be based on the conditions of use to select standards, items and indicators to obtain the required inspection data.