Assay— Inject an appropriate derivatized specimen into a gas chromatograph (see Chromatography 621) equipped with a flame-ionization detector, helium being used as the carrier gas. The following conditions have been found suitable: a 0.25-mm × 30-m capillary column coated with a 1-µm layer of phase G2; the injection port temperature is maintained at 250; the detector temperature is maintained at 280; the column temperature is maintained at 230 and programmed to rise 4 per minute to 280. The area of the C12H22O11·H2O peak is not less than 97% of the total peak area.

Assay— Inject an appropriate derivatized specimen into a gas chromatograph (see Chromatography 621) equipped with a flame-ionization detector, helium being used as the carrier gas. The following conditions have been found suitable: a 0.25-mm × 30-m capillary column coated with a 1-µm layer of phase G43; the injection port temperature is maintained at 250; the detector temperature is maintained at 250; the column temperature is maintained at 20 and programmed to rise 8 per minute to 280. The area of the C12H22O11 peak is not less than 99% of the total peak area.

Assay— Accurately weigh about 300 mg, freshly ignited in a muffle furnace at 600 ± 50, and dissolve it by warming with 10 mL of water and 1 mL of glacial acetic acid. Dilute with 75 mL of water, heat to boiling, add 50.0 mL of 0.1 N potassium dichromate VS, and boil for 2 to 3 minutes. Cool, transfer to a 200-mL volumetric flask with the aid of water, dilute with water to volume, mix, and allow to settle. Withdraw 100.0 mL of the clear liquid, and transfer to a glass-stoppered flask. Add 10 mL of diluted sulfuric acid and 1 g of potassium iodide, insert the stopper, mix gently, and allow to stand for 10 minutes. Then titrate the liberated iodine, representing the excess of dichromate, with 0.1 N sodium thiosulfate VS, adding 3 mL of starch TS as the endpoint is approached: each mL of 0.1 N potassium dichromate is equivalent to 7.440 mg of PbO. Not less than 98% is found.

Insoluble in acetic acid— Dissolve 2 g in 30 mL of dilute glacial acetic acid (1 in 2), boil gently for 5 minutes, filter, wash the residue with diluted acetic acid, and dry at 105 for 2 hours: the residue weighs not more than 10 mg (0.5%).

Substances not precipitated by hydrogen sulfide— Completely precipitate the lead from the filtrate obtained in the test for Insoluble in acetic acid by passing hydrogen sulfide into it, filter, and wash the precipitate with 20 mL of water. To one-half of the mixed filtrate and washings add 5 drops of sulfuric acid, evaporate to dryness, and ignite at 800 ± 25 for 15 minutes: the residue weighs not more than 5 mg (0.5%).

Volatile substances— Accurately weigh about 5 g, and heat strongly in a covered porcelain crucible: it loses not more than 2.0% of its weight.

Melting range 741 : between 175 and 180.

Assay— When tested by thin-layer chromatography, with the use of plates coated with chromatographic silica gel mixture, a developing system consisting of a mixture of toluene, 1,4-dioxane, and acetic acid (15.2:4.2:0.6), and sprayed with a mixture of sulfuric acid and methanol (1:1), heated at 110 for 20 minutes, and examined visually and under long-wavelength UV light, a single spot is exhibited.

Melting range 741 : between 184 and 186.

Description— Cubes, masses, fragments, or granules, of an indigo blue or deep violet color. Has the combined odor of indigo and violets, and tinges the saliva a deep blue. The indicator substances it contains are soluble in water and less soluble or insoluble in alcohol.

Ash— It yields not more than 60.0% of ash.

Specific rotation 781 : between +25.5 and +26.0.

Test solution: 20 mg per mL, in dilute hydrochloric acid (1 in 2).

Nitrogen content, Method I 461 : between 18.88% and 19.44% of N is found, corresponding to not less than 98.5% of C6H14N2O2, the test specimen previously having been dried at 105 for 2 hours.