Inspection method of stearic acid

Water-soluble acid: Take 5g of this product, melt it by heating, add new boiling hot water of equal volume, shake for 2 minutes, let cool, filter, add 1 drop of methyl orange indicator liquid to the filtrate, it shall not show red.

Neutral fat or wax: Take 1.0g of this product, add 0.5g of anhydrous sodium carbonate and 30mL of water, boil to dissolve, and the solution should be clear.

Residue on ignition: Take 4.0g of this product and inspect according to law. The remaining residue shall not exceed 0.1%.

Heavy metal: Take the residue left under the item of residue on ignition and inspect according to law, and the content of heavy metal shall not exceed 5 parts per million.