Potassium sorbate is white to light yellow scaly crystals, crystal particles or crystal powder. Odorless or slightly odorous. It is easily absorbed by moisture and oxidized and decomposed for a long time. Easily soluble in water. Soluble in propylene glycol and ethanol.
Identification of potassium sorbate:
Take about 0.l g of this product, add 10ml of water to dissolve, add 1m l of acetone, add dilute hydrochloric acid to make it acidic, add 2 drops of bromine solution and shake it to make the bromine solution fade.
Take this product, add water to make a solution containing 0.2mg per lm l, take an appropriate amount, add 0.lm o l/L hydrochloric acid solution to make a solution containing 2Mg per lm l, and determine it according to the ultraviolet-visible spectrophotometry (General Rule 0401) that there is maximum absorption at a wavelength of 264nm.
The infrared light absorption map of this product should be consistent with the control map (Spectral Set 688 Figure) (General Rule 0402).
The flame reaction of potassium salts in the aqueous solution of this product (Tongye 0301).
Acceptance of potassium sorbate:
Pharmacy:
Take l.0 g of this product, add 2 drops of phenolphthalein indicator liquid. If it looks light red, add hydrochloric acid titration solution (O.lmo l/L) 0.25ml, and the light red should disappear; if it is colorless, add sodium hydroxide titration solution (0.1m o l/L) 0.25ml, and the light red should be displayed.
Clarity and color of the solution:
Take 0.20g of this product, add 5ml of water to dissolve, and check according to law (General Rules 0901 and General Rules 0902 The solution should be clear and colorless; if color is developed, compare it with the standard colorimetric solution of yellow No. 3 (General Rules 0901 first method, it must not be deeper.
Chloride:
Take 0.40g of this product, add 15ml of water to dissolve, add 10ml of dilute nitric acid while stirring, filter, wash the residue with 10ml of water in batches, combine the filtrate and washing solution, add water to make about 40ml, and check according to law (General Rules 08 0 1) Compared with the control solution made of 7.0ml of standard sodium hydrogen chloride solution, it must not be more concentrated (0.018%).
Sulphate:
Take 1.05g of this product, add 30ml of water to dissolve, add 2m l of dilute hydrochloric acid while stirring, filter, wash with 8m l of water in batches, combine the filtrate and wash solution, add water to make about 40m l, check according to law (General Rule 0802), and compared with the control solution made of 4.0ml of standard potassium sulfate solution, it must not be more concentrated (0.038%).
Aldehyde:
Take this product l.O g, put it in a 100ml measuring flask, add 50ml isopropanol and 30ml water to dissolve, use lm o l/L hydrochloric acid solution to adjust the pH value to 4 (use precision pH test strip), add water to dilute to scale, shake well, take 10m l, place it in Nass colorimetric tube, add magenta-sulfite test solution (take alkaline magenta 0.2g, dissolve in 120m l hot water, let cool, add 10% crystalline sodium sulfite solution 20m l and 2ml hydrochloric acid, mix well) lm l, shake well, and leave for 30 minutes, and use standard formaldehyde solution (take the appropriate amount of formaldehyde solution, add water to make a solution containing 0.lm g of formaldehyde in lm l) 1.0m l, add isopropanol 5m l and water 4m l Comparison solution made by the same method must not be deeper (0.1%).
Dry weight loss:
Take this product and dry it to a constant weight at 10 5 1, and lose weight loss shall not exceed 1.0% (General rule 0831).
Heavy metal:
Take this product 2.0 g, place it in a crucible, add 0.5g of magnesium oxide, and slowly heat it to make it white or off-white. Then burn it at 800°C for 1 hour. Use hydrochloric acid solution (1-2) 10m l dissolve the residue in 2 times, add concentrated ammonia solution dropwise to appear neutral to the phenolphthalein indicator liquid, let cool, add glacial acetic acid to make the red disappear, then add glacial acetic acid 0.5m l and acetate buffer (pH 3.5) 2m l, transfer to Nass colorimetric tube, add water to dilute it to 25m l; take another standard lead solution 2.0ml, add magnesium oxide 0.5g, operate the same as above method, check according to law (General Rule 0821 First Method), and contain no more than 10 parts per million.
Arsenic salt:
Take 0.67g of this product, add calcium hydroxide l.O. g, mix, add a small amount of water, stir evenly, after drying, first burn with low heat to charcoal, then burn at 500~600°C to completely ash, let cool, add 5m l hydrochloric acid and 23ml of water to dissolve, check according to law (General Rule 0822 First Law), and should comply with regulations (0.0003%).
