DEFINITION
Mixture of variable proportions of hydrated manganese (II) (2RS)-2,3-dihydroxypropyl phosphate and hydrated manganese (II) 2-hydroxy-1-(hydroxymethyl)ethyl phosphate.
Content: 97.0 per cent to 102.0 per cent (dried substance).
CHARACTERS
Appearance: White or pale pink, hygroscopic powder.
Solubility: Practically insoluble in water and in ethanol (96 per cent). It is freely soluble in dilute mineral acids.
IDENTIFICATION
A. Mix 1 g with 1 g of potassium hydrogen sulphate R in a test tube fitted with a delivery tube. Heat strongly and direct the white vapour towards a piece of filter paper impregnated with a freshly prepared 10 g/l solution of sodium nitroprusside R. The filter paper develops a blue colour in contact with piperidine.
B. Disperse 50 mg in 5 ml of water R. Add 0.5 ml of ammonium sulphide solution. A pale pink precipitate is formed that dissolves on the addition of 1 ml of acetic acid R.
C. Ignite 0.1 g in a crucible. Take up the residue with 5 ml of nitric acid R and heat on a water-bath for 1 min. Filter. The filtrate gives reaction (b) of phosphates.
TESTS
Solution S: Dissolve 5.0 g in 20 ml of dilute hydrochloric acid. Filter if necessary. Add dilute ammonia until a precipitate is formed. Dissolve the precipitate by adding the minimum quantity needed of dilute hydrochloric acid and dilute to 100 ml with distilled water.
Glycerol and ethanol (96 per cent)-soluble substances: Maximum 1.0 per cent.
Shake 1.00 g with 25 ml of ethanol (96 per cent) for 1 min. Filter. Evaporate the filtrate to dryness on a water-bath and dry the residue at 70 °C for 1 h. The residue weighs a maximum of 10 mg.
Chlorides: Maximum 0.15 per cent.
Phosphates: Maximum 0.3 per cent.
Sulphates: Maximum 0.2 per cent.
Iron: Maximum 50 ppm.
Heavy metals: Maximum 20 ppm.
Loss on drying: Maximum 12.0 per cent, determined on 1.000 g by drying in an oven at 105 °C for 4 h.
ASSAY
To 0.200 g add 50 ml of water and stir until dissolution. Add 10 mg of ascorbic acid, 20 ml of ammonium chloride buffer solution pH 10.0 and 0.3 ml of a 2 g/l solution of mordant black 11 in triethanolamine. Titrate with 0.1 M sodium edta until the colour changes from violet to pure blue.
C3H7MnO6P·xH2O Formula wt, anhydrous 225.00
CAS: [1320-46-3]
DESCRIPTION
Manganese Glycerophosphate occurs as a white or pink-white powder. One gram dissolves in about 5 mL of 1:4 citric acid solution. It is slightly soluble in water, and is insoluble in alcohol.
REQUIREMENTS
Identification: A 1:20 solution in 2.7 N hydrochloric acid gives positive tests for Manganese.
Assay: Not less than 98.0% and not more than 100.5% of C3H7MnO6P after drying.
Lead: Not more than 4 mg/kg.
Loss on Drying: Not more than 12.0%.
