硼酸

Boric Acid BP Eur

H3BO3 -- 61.8 -- CAS 10043-35-3Boric Acid BP

DEFINITIONBoric acid contains not less than 99.0 per cent and not more than the equivalent of 100.5 percent of H3BO3.

CHARACTERSA white, crystaler, colourless, shiny plates greasy to the touch, or white crystals, soluble in water and in alcohol, freely soluble in boiling water and in glycerol (85 per cent).

IDENTIFICATIONA. Dissolve 0.1 g by gently heating in 5 ml of methanol, add 0.1 ml of sulric acid and ignite the solution. The flame has a green border.B. Solution S (see Tests) is acid.

TESTSSolution SDissolve 3.3 g in 80 ml of boiling distilled water, cool and dilute to 100 ml with carbon dioxide-free water prepared from distilled water.Appearance of solutionSolution S is clear and colourless.br>The of solution S is 3.8 to 4.8.Solubility in alcoholDissolve 1.0 g in 10 ml of boiling alcohol. The solution is not more opalescent than reference suspension and is colourless.Organic matterIt does not darken on progressive heating to dull redness.Sultes10 ml of solution S diluted to 15 ml with distilled water complies with the limit test for sultes (450 ppm).Heavy metals