Assay— Accurately weigh about 500mg,transfer to a suitable container,add 30mLof water,and mix.Add 40mLof water,and mix.Add phenolphthalein TS,and titrate with 0.1Nsodium hydroxide VS.Each mLof 0.1Nsodium hydroxide is equivalent to 10.21mg of C5H10O2:not less than 99.0%of C5H10O2is found.

Assay— Inject an appropriate specimen into a suitable gas chromatograph (see Chromatography á621ñ)equipped with a flame-ionization detector,helium being used as the carrier gas.The following conditions have been found suitable:a 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 300;the column temperature is maintained at 150and programmed to rise 10per minute to 300.The area of the C11H14Opeak is not less than 98%of the total peak area.

Refractive index á831ñ: 1.5149at 20.

Boiling range: between 105and 107,at a pressure of 5mm of mercury.

Assay— Transfer about 400mg,accurately weighed,to a 500-mLconical flask,and add 150mLof water and 30mLof dilute sulfuric acid (1in 2).Boil the solution on a hot plate for 5minutes,add 50mLof water,and continue boiling until a yellow solution is obtained.Transfer the hot plate and the flask to a well-ventilated hood,and bubble sulfur dioxide gas through the solution for 10minutes,or until the solution is a clear,brilliant blue color.Rinse the gas delivery tube into the flask with a few mLof water,then bubble carbon dioxide gas through the solution for 30minutes while continuing to boil the solution gently.Cool the solution to about 80,and titrate with 0.1Npotassium permanganate VSto a yellow-orange endpoint.Perform a complete blank determination,and make any necessary correction.Each mLof 0.1Npotassium permanganate is equivalent to 9.095mg of V2O5.Not less than 99.5%is found.

Assay— Accurately weigh about 400mg of the dried test specimen obtained in the test for Water,and transfer with 15to 20mLof water into a beaker.Add 3mLof sulfuric acid,cover the beaker with a watch glass,and heat on a steam bath until all dissolves.Cool,dilute with 125mLof water,and titrate with 0.1Npotassium permanganate VSto the production of a pinkish color that persists for 1minute:each mLof 0.1Npotassium permanganate is equivalent to 16.30mg of VOSO4.Not less than 97%is found.

Water— Dry about 1g,accurately weighed,at 220to constant weight:it loses not more than 50.0%of its weight.

Pentavalent vanadium— Heat 1g,accurately weighed,with 50mLof water and 5mLof hydrochloric acid in a flask until dissolved.Cool,add 2g of potassium iodide,insert the stopper,and allow to stand for 30minutes.Add 50mLof water,and titrate the liberated iodine with 0.1Nsodium thiosulfate VS,adding 3mLof starch TSas the indicator.Correct for the volume of thiosulfate consumed by a blank.Each mLof 0.1Nthiosulfate is equivalent to 5.095mg of vanadium (V).Not more than 0.5%is found,calculated on the dried basis.

Substances not precipitated by ammonia— Dissolve 1.0g by heating with 20mLof water and 2mLof hydrochloric acid.Dilute with water to about 75mL,and neutralize to litmus paper with ammonia TS.Transfer the solution to a cylinder,slowly add 5mLof ammonia TSand sufficient water to make 100mL,and allow to stand overnight.Decant 50mLof the supernatant through a filter,add 5drops of sulfuric acid,evaporate to dryness,and ignite:the residue weighs not more than 10mg (2.0%).

Assay— Inject an appropriate volume into a gas chromatograph (see Chromatography á621ñ)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 G2;the injection port temperature is maintained at 100;the detector temperature is maintained at 300;and the column temperature is maintained at 0and programmed to rise 10per minute to 150.The area of the CH3COOCH=CH2peak is not less than 99%of the total peak area.

Assay— Inject an appropriate volume into a gas chromatograph (see Chromatography á621ñ)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 G2;the injection port temperature is maintained at 250;the detector temperature is maintained at 300;and the column temperature is maintained at 100and programmed to rise 10per minute to 250.The area of the C6H9NOpeak is not less than 99.0%of the total peak area.

Water,Method 1á921ñ: not more than 0.1%,determined on 2.5g,using a mixture of 50mLof methanol and 10mLof butyrolactone as the solvent.