Packaging and storage
Preserve in tight containers.
Labeling
Label Syrup in terms of the content of ferrous sulfate (FeSO4·7H2O) and in terms of the content of elemental iron.
Identification
Dissolve 1 mL of Syrup with water to about 100 mL: the solution responds to the tests for
Ferrous Salts 191 and for
Sulfate 191.
Assay
Transfer 25 mL of Syrup, accurately measured, to a 250-mL conical flask. Add 15 mL of 2 N sulfuric acid and 100 mL of water, and shake well. Add 3 drops of orthophenanthroline TS, and titrate with 0.1 N ceric sulfate VS. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N ceric sulfate is equivalent to 27.80 mg of ferrous sulfate (FeSO4·7H2O).