Assay— When examined by gas-liquid chromatography,using suitable gas chromatographic apparatus and conditions,it shows a purity of not less than 99%.

Assay— Transfer about 1g,accurately weighed,to a suitable,tared crucible,moisten with a few drops of sulfuric acid,and ignite gently to constant weight.Each mg of residue is equivalent to 3.662mg of C10H21NaO4S.Not less than 95%is found.

Insoluble matter— Boil 1g with 30mLof water in a small flask:the solution is colorless and clear,or not more than opalescent.

Loss on drying á731ñ— Dry it at 105to constant weight:it loses not more than 10.0%of its weight.

Residue on ignition(Reagent test)— Ignite 1g with 0.5mLof sulfuric acid:the residue weighs not more than 5mg (0.5%).

Chloride(Reagent test)— Dissolve 3g in 75mLof boiling water,cool,dilute with water to 75mL,and filter if necessary.To 25mLof the filtrate add 2mLof nitric acid and 1mLof silver nitrate TS,and allow to stand for 5minutes:any turbidity produced is not greater than that of a control containing 0.02mg of added Cl (0.002%).

Sulfate(Reagent test,Method I)— To a 25-mLportion of the filtrate from the preceding test add 0.5mLof diluted hydrochloric acid and 2mLof barium chloride TS,and allow to stand for 10minutes:any turbidity produced is not greater than that of a control containing 0.2mg of added SO4(0.02%).

Alcohol-soluble substances— Boil 1g with 20mLof alcohol for 5minutes under a reflux condenser,and filter while hot.Evaporate 10mLof the filtrate on a steam bath,and dry at 105:the residue weighs not more than 5mg (1%).

Reducing sugars— Shake 2g with 100mLof water for 10minutes,and filter until clear.To 50mLof the filtrate add 50mLof alkaline cupric tartrate TS,and boil for 3minutes.Filter through a tared filtering crucible,wash with water,then with alcohol,and finally with ether,and dry at 105for 2hours:the precipitate of cuprous oxide weighs not more than 115mg (corresponding to about 5%of reducing sugars as dextrose).

Insoluble matter— Dissolve 2g in 100mLof water,without heating,and filter immediately:the insoluble residue does not exceed 1mg (0.05%).

Residue on ignition(Reagent test): not more than 1mg,from 2g (0.05%).

Suitability test for detection of selenium— Dissolve 1.633g of selenious acid (H2SeO3)in water,and dilute with water to 1liter.Dilute 10mLof this solution with water to 1liter,to make a solution containing 0.010mg of Se per mL.Place 1mLof the resulting solution in a 100-mLbeaker,add 2mLof formic acid solution (1in 7),and dilute with water to 50mL.Add 2mLof 3,3¢-diaminobenzidine hydrochloride solution (1in 200),and allow to stand for 30to 50minutes.Adjust with 6Nammonium hydroxide to a pHbetween 6and 7.Transfer to a 125-mLseparator,add 10.0mLof toluene,and shake vigorously for 30seconds:a distinct yellow color is produced in the toluene layer.Ablank containing diaminobenzidine hydrochloride but no selenium standard,treated in the same manner,shows no color in the toluene layer.

Loss on ignition— Accurately weigh about 4g,and ignite to constant weight:it loses not more than 10.0%of its weight.

Organic impurities— It does not darken appreciably upon ignition.

Loss on drying á731ñ— Dry it at 110for 2hours:it loses not more than 2.0%of its weight.

Melting range á741ñ: between 82and 84.

Solubility in alcohol— Asolution of 100mg in 10mLof alcohol is not more than faintly turbid.

Residue on ignition(Reagent test)— Ignite 500mg with 0.5mLof sulfuric acid:the residue weighs not more than 1mg (0.2%).

Sensitiveness— To 10mLof a water solution containing 0.01mg of phenol add 0.3mLof a sodium borate buffer (made by dissolving 2.84g of crystallized sodium borate in 90mLof warm water,adding 8.2mLof 1Nsodium hydroxide and diluting with water to 100mL)and 0.1mLof a solution of 10mg of the test specimen in 20mLof alcohol:a distinct blue color develops within 10minutes.

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 phase G2;the injection port temperature is maintained at 200;the detector temperature is maintained at 300;and the column temperature is maintained at 100and programmed to rise 10per minute to 200.The area of the C8H19Npeak is not less than 99%of the total peak area.

Refractive index á831ñ: between 1.415and 1.419at 20.

Assay— Accurately weigh about 2g into a suitable flask,add 25.0mLof 1Nsodium hydroxide and 30mLof isopropyl alcohol,and mix.Digest the mixture at a temperature near boiling for 30minutes,then cool in a water bath to room temperature.Add phenolphthalein TS,and titrate with 1Nsulfuric acid VSto the disappearance of the pink color.Perform a complete blank determination,and make any necessary correction.Each mLof 1Nsulfuric acid consumed is equivalent to 139.2mg of C16H22O4.Not less than 98%is found.

Refractive index á831ñ: between 1.491and 1.493at 20.

Acid content— Accurately weigh about 10g,and dissolve in 100mLof an alcohol-ether mixture (1:1).Add phenolphthalein TS,and titrate immediately with 0.05Nalcoholic potassium hydroxide VS.Each mLof 0.05Nalcoholic potassium hydroxide is equivalent to 4.15mg of phthalic acid:not more than 0.02%is found.

Melting range,Class Iá741ñ: between 49and 50.

Melting range á741ñ: between 38and 41.

Assay— When examined by gas-liquid chromatography,with the use of suitable apparatus and conditions,it shows a purity of not less than 98%.

Density: between 1.299and 1.301.

Refractive index á831ñ: between 1.548and 1.550at 25.

Residue on evaporation— Evaporate 80mLon a steam bath,and dry at 105for 1hour:the residue weighs not more than 50mg (0.005%).

Acidity— Add phenolphthalein TSto 25mLof methanol,and titrate with 0.02Nalcoholic potassium hydroxide VSuntil a faint pink color persists for 15seconds.Pipet 25mLof test specimen into the solution,mix,avoiding exposure to the atmosphere,and titrate with 0.02Nalcoholic potassium hydroxide VS:not more than 2.2mLis required to restore the pink color (about 0.005%).

Assay—

Residue on ignition(Reagent test)— Ignite 200mg with 5drops of sulfuric acid:the residue weighs not more than 1mg (0.5%).

Sensitiveness— Dissolve 100mg in 60mLof alcohol,add 2.5mLof 0.1Nsodium hydroxide,and dilute with water to 100mL.Add 1mLof this solution to a solution of potassium iodide prepared by dissolving 100mg of potassium iodide,previously dried at 105to constant weight and accurately weighed,in 50mLof water containing 1mLof glacial acetic acid,and titrate with 0.1Nsilver nitrate VSuntil the color of the precipitate changes from pale yellowish orange to pink.The volume of 0.1Nsilver nitrate consumed is not more than 0.10mLgreater than the calculated volume,the calculated volume being based upon the KIcontent of the dried specimen as determined in the Assayunder Potassium Iodide(USPmonograph).

Assay— Inject an appropriate specimen into a gas chromatograph (see Chromatography á621ñ)equipped with a thermal-conductivity detector,helium being used as the carrier gas.The following conditions have been found suitable:a 0.53-mm ×30-m capillary column coated with a 5-µm layer of phase G2;the injection port temperature is maintained at 200;the detector temperature is maintained at 200;and the column temperature is maintained at 0and programmed to rise 5per minute to 40,and then to rise at 10per minute to 180.The area of the CHCl2Fpeak is not less than 98%of the total peak area.

Melting range á741ñ: between 103and 107,but the range between beginning and end of melting does not exceed 2.

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 phase G2;the injection port temperature is maintained at 230;the detector temperature is maintained at 300;the column temperature is maintained at 130and programmed to rise 10per minute to 280.The area of the C6H4Cl2Opeak is not less than 98.5%of the total peak area.

Assay— Inject an appropriate specimen 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 phase G2;the injection port temperature is maintained at 250;the detector temperature is maintained at 300;and the column temperature is maintained at 150and programmed to rise 10per minute to 280.The area of the C8H6Cl2O2peak is not less than 97%of the total peak area.

Melting range á741ñ: between 65and 67.

Solubility in alcohol— Asolution of 100mg in 10mLof alcohol is complete and clear.

Residue on ignition— Ignite 500mg with 0.5mLof sulfuric acid:the residue weighs not more than 1mg (0.2%).

Sensitiveness— It meets the requirements of the test for Sensitivenessunder 2,6-Dibromoquinone-chlorimide.

Add the following:

Assay— Accurately weigh about 400mg in a tared,small weighing bottle equipped with a well-fitting closure.Transfer the stoppered bottle to a 250-mLbeaker,add sufficient glacial acetic acid TSto cover the bottle,and open the bottle under the surface of the acid.Add crystal violet TS,and titrate with 0.1Nperchloric acid VS.Each mLof 0.1Nperchloric acid is equivalent to 18.13mg of (C6H11)2NH.Not less than 98%is found.

Specific gravity á841ñ: between 0.911and 0.917.

Boiling range(Reagent test): between 255and 257.

Water,Method Iá921ñ: not more than 0.5%.

Assay— Inject an appropriate specimen (about 0.2µL)into a suitable gas chromatograph (see Chromatography á621ñ)equipped with a flame-ionization detector,helium being used as the carrier gas flowing at about 40mLper minute.The following conditions have been found suitable:a 3-mm ×1.8-m stainless steel column containing 20%phase G16on support S1A;the injection port temperature is maintained at 250;the column temperature is maintained at 140and programmed to rise 6per minute to 200.The detector temperature is maintained at 310.The area of the N,N-diethylaniline peak having a retention time of about 4.9minutes is not less than 99%of the total peak area.

Refractive index á831ñ: between 1.5405and 1.5425at 20.

Specific gravity á841ñ: between 1.117and 1.120at 20.

Distilling range á721ñ: between 240and 250.

Acidity— Transfer 54mL(60g)to a 250-mLconical flask,add phenolphthalein TS,and titrate with 0.02Nalcoholic potassium hydroxide VSto the production of a pink color that is stable for at least 15seconds:not more than 2.5mLis consumed (0.005%as CH3COOH).

Water á921ñ: not more than 0.2%.

Residue on ignition á281ñ— Transfer 50g to a tared platinum dish,heat the dish gently until the vapors ignite,and allow the specimen to burn completely.Ignite the residue at 800±25,cool,and weigh:the residue weighs not more than 2.5mg (0.005%).

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 0.25-mm ×30-m capillary column coated with G2.The injection port temperature is maintained at 200;the column temperature is maintained at 100and programmed to rise 10per minute to 250and held there for 5minutes.The detector temperature is maintained at 300.The area of the main peak is not less than 95%of the total peak area.

Refractive index á831ñ: between 1.4815and 1.4845at 20.

Specific rotation á781ñ: between -47and -49,determined in a solution in 75percent acetic acid containing 100mg per mL.

Solubility in alcohol— Asolution of 500mg in 20mLof warm alcohol is colorless and complete.

Loss on drying á731ñ— Dry it at 105to constant weight:it loses not more than 6%of its weight.

Residue on ignition(Reagent test): not more than 0.3%.

Assay— When tested by thin-layer chromatography,with the use of plates coated with chromatographic silica gel mixture,a developing system consisting of toluene and methanol (80:20),and examined visually and under long-wavelength UVlight,a single spot is exhibited.

Assay—

Assay—

Assay— Dissolve about 75mg,accurately weighed,in 30mLof methanol.Slowly add 40mLof water.Titrate with 0.1Nsodium hydroxide VS,determining the endpoint potentiometrically.Perform a blank determination and make any necessary correction.Each mLof 0.1Nsodium hydroxide is equivalent to 15.41mg of C7H6O4.Not less than 99%is found.

Melting range á741ñ: about 207,with decomposition.

Residue on ignition— Ignite 200mg with 5drops of sulfuric acid:the weight of the residue does not exceed 1.0mg (0.5%).

Sensitiveness— Weigh accurately about 100mg of potassium iodide,previously dried at 105to constant weight,and dissolve it in 50mLof water.Add 1mLof diiodofluorescein TSprepared from the test specimen and 1mLof glacial acetic acid,and titrate with 0.1Nsilver nitrate VSuntil the color of the precipitate changes from brownish red to a bluish red.The volume of 0.1Nsilver nitrate consumed is not in excess of 0.10mLover the calculated volume,based on the KIcontent of the dried potassium iodide determined as follows.Dissolve about 500mg of potassium iodide,accurately weighed,in about 10mLof water,and add 35mLof hydrochloric acid and 5mLof chloroform.Titrate with 0.05Mpotassium iodate VSuntil the purple color of iodine disappears from the chloroform.Add the last portions of the iodate solution dropwise,agitating vigorously and continuously.After the chloroform has been decolorized,allow the mixture to stand for 5minutes.If the chloroform develops a purple color,titrate further with the iodate solution.Each mLof 0.05Mpotassium iodate is equivalent to 16.60mg of KI.

Specific gravity: between 0.716and 0.720.

Distilling range,Method IIá721ñ— Not less than 95%distils between 65and 70.

Peroxides— To 10mL,contained in a clean,glass-stoppered cylinder previously rinsed with a portion of the ether under examination,add 1mLof freshly prepared potassium iodide solution (1in 10).Shake,and allow to stand for 1minute:no yellow color is observed in either layer (about 0.001%as H2O2).

Residue on evaporation— [Note—If peroxide is present,do not carry out this procedure.]Evaporate 14mL(10g)from a tared shallow dish,and dry at 105for 1hour:the residue weighs not more than 1mg (0.01%).

Acidity— Add 2drops of bromothymol blue TSto 10mLof water in a glass-stoppered,50-mLflask,and titrate with 0.010Nsodium hydroxide until a blue color persists after vigorous shaking.Add 5mLof Diisopropyl Ether,and titrate with 0.010Nsodium hydroxide:not more than 0.30mLis required to restore the blue color (0.005%as CH3COOH).

NOTE—For spectrophotometric determinations,use diisopropyl ether that meets the following additional requirement:

Absorbance— Its absorbance at 255nm,in a 10-mm quartz cell,does not exceed 0.2,water being used as the blank.

Assay— Not less than 98%of C6H15Nis found,a suitable gas chromatograph equipped with a flame-ionization detector being used.The following conditions have been found suitable:a 3.2-mm ×1.83-m stainless steel column is packed with a cross-linked polystyrene support;the injection port temperature is maintained at 250and the detector at 310;the column temperature is programmed to rise at 10per minute from 50to 220.

Refractive index á831ñ: between 1.3915and 1.3935,at 20.

Assay— Accurately weigh about 500mg,dissolve in 50mLof glacial acetic acid,mix,add crystal violet TS,and titrate with 0.1Nperchloric acid VS.Each mLof 0.1Nperchloric acid is equivalent to 12.92mg of C8H19N.Not less than 98%is found.

Refractive index á831ñ: between 1.4125and 1.4145at 20.

Assay— Inject an appropriate specimen into a suitable gas chromatograph (see Chromatography á621ñ)equipped with a flame-ionization detector,nitrogen being used as the carrier gas.The following conditions have been found suitable:a 0.3-mm ×30-m capillary column coated with phase G1;the injection port temperature is maintained at 270;the detector temperature is maintained at 300;the column temperature is maintained at 150and programmed to rise 10per minute to 270.The area of the main peak is not less than 97%of the total peak area.

Melting range á741ñ: between 50and 52.

Boiling range(Reagent test)— Not less than 95%distils between 83and 86.

Refractive index á831ñ: between 1.379and 1.381,at 20.

Acidity— To 20mLadd bromophenol blue TS,and titrate with 0.020Nsodium hydroxide:not more than 2.0mLis consumed (about 0.015%as CH3COOH).

Water,Method Iá921ñ: not more than 0.2%.

Melting range á741ñ: between 65and 67.

Assay—

Refractive index á831ñ: between 1.514and 1.518at 20.

Melting range á741ñ: between 109and 111.

Assay— When examined by gas-liquid chromatography,with the use of suitable apparatus and conditions,it shows a purity of not less than 99%.

Distilling range á721ñ: between 164.5and 167.5.

Residue on evaporation— Evaporate 215mLon a steam bath,and dry at 105for 1hour:the residue weighs not more than 2mg (0.001%).

pHof 20%solution— Weigh 20g of it into a 100-mLvolumetric flask,and dilute with carbon dioxide-free water to volume:the solution shows a pHbetween 4.0and 7.0.

Ultraviolet absorbance— Determine its absorbance throughout the range 270to 400nm,using a 1-cm cell,a suitable spectrophotometer,and water to set the instrument:the absorbance does not exceed 1.00at 270nm,0.30at 280nm,0.15at 290nm,0.05at 310nm,0.03at 320nm,and 0.01at 360to 400nm.

Water,Method Iá921ñ: not more than 0.05%.

Solubility— Insoluble in water;sparingly soluble in chloroform,in ether,or in fatty oils.Dissolve 100mg in 20mLof alcohol:the solution is complete or practically so and clear.

Melting range á741ñ: between 115and 117.

Residue on ignition á281ñ: not more than 0.1%.

Sensitiveness— Add 0.05mLof an alcohol solution (1in 200)and 2g of ammonium chloride to 25mLof carbon dioxide-free water:the lemon-yellow color of the solution is changed to orange by the addition of 0.05mLof 0.1Nhydrochloric acid and restored on the subsequent addition of 0.05mLof 0.1Nsodium hydroxide.

Melting range á741ñ: between 132and 136.

Melting range á741ñ: between 83and 85.

Refractive index á831ñ: about 1.5609at 20.

Assay— Inject an appropriate specimen (about 0.2µL)into a suitable gas chromatograph (see Chromatography á621ñ)equipped with a flame-ionization detector,helium being used as the carrier gas flowing at about 40mLper minute.The following conditions have been found suitable:a 3-mm ×1.8-m stainless steel column containing 20%phase G16on support S1A;the injection port temperature is maintained at 250;the column temperature is maintained at 50and programmed to rise 10per minute to 200.The detector temperature is maintained at 310.The area of the N,N-dimethylaniline peak having a retention time of about 11.5minutes is not less than 99%of the total peak area.

Refractive index á831ñ: between 1.5571and 1.5591at 20.

Boiling range(Reagent test)— Distill 100mL:the difference between the temperatures observed,when 1mLand 95mLhave distilled,is not more than 2.5.Its boiling temperature at a pressure of 760mm of mercury is 194.2.

Hydrocarbons— Dissolve 5mLin a mixture of 10mLof hydrochloric acid and 15mLof water:a clear solution results and it remains clear on cooling to about 10.

Aniline or monomethylaniline— Place 5mLin a glass-stoppered flask,add 5mLof a solution of acetic anhydride in benzene (1in 10),mix,and allow to stand for 30minutes.Add 30.0mLof 0.5Nsodium hydroxide VS,shake the mixture,add phenolphthalein TS,and titrate with 0.5Nhydrochloric acid VS.Perform a blank determination,and make any necessary correction.Not more than 0.30mLof 0.5Nsodium hydroxide is consumed by the test specimen.

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 0.25-mm ×30-m capillary column coated with phase G1:the detector temperature and the injection port temperature are maintained at 300;the column temperature is maintained at 180and programmed to rise at the rate of 10per minute to 280and held at that temperature for 10minutes.The area of the main peak is not less than 99%of the total peak area.

Melting range á741ñ: between 148and 150.

Add the following:

Add the following:

Assay— Transfer about 250mg,accurately weighed,to a suitable beaker,add 100mLof glacial acetic acid,and dissolve by stirring.When solution is complete,titrate with 0.1Nperchloric acid VS,determining the endpoint potentiometrically.Perform a blank determination,and make any necessary correction.Each mLof 0.1Nperchloric acid is equivalent to 17.12mg of C12H13N.Not less than 98%is found.

Refractive index á831ñ: between 1.6210and 1.6230at 20,sodium light being used.

Sulfanilamide test— Dissolve 20mg of USP Sulfanilamide RSin 100mLof water to obtain the Sulfanilamide solution.Into two 150-mLbeakers pipet 1.0mLand 2.5mLof the Sulfanilamide solution,respectively.Dilute with water to 90mL.To provide a blank,place 90mLof water in a third beaker.To each beaker add 8.0mLof trichloroacetic acid solution (3in 20)and 1.0mLof sodium nitrite solution (1in 1000).Stir the solutions for 5minutes,then add 10mLof acetate buffer TS,and 1.0mLof a 1in 1000solution of N,N-dimethyl-1-naphthylamine in alcohol.The pHis about 5to 6,using pHpaper.Stir for an additional 5minutes,then add 20mLof glacial acetic acid.The pHis about 3to 4,using pHpaper.In comparison with the blank,the beaker containing 1.0mLof the Sulfanilamide solutionshows a pink color,while the other beaker shows a deep pink to red color.

Refractive index á831ñ: 1.4243at 20.

Assay— Inject a 1in 3solution of it in xylene into a suitable gas chromatograph equipped with a flame-ionization detector,helium being used as the carrier gas at a flow rate of about 40mLper minute.The following conditions have been found suitable:a 3.2-mm ×1.83-m stainless steel column packed with 10%phase G25on support S1A;the injection port is maintained at about 250and the detector at about 310;the column temperature is programmed to rise at 8per minute from 100to 200.Similarly inject a specimen of xylene.The area of the C8H10Opeak is not less than 98%of the total peak area corrected for xylene.

Melting range á741ñ: between 44and 46.

Assay— Transfer about 400mg,accurately weighed,to a 250-mLbeaker,and dissolve in about 75mLof water.Titrate with 0.1Nsodium hydroxide VS,determining the endpoint potentiometrically.Each mLof 0.1Nsodium hydroxide is equivalent to 10.46mg of C8H12N2·2HCl.Not less than 98%is found.

Solubility— Asolution of 1g in 10mLof water produces not more than a slight haze.

Melting range á741ñ: between 89and 92.

Residue on ignition(Reagent test): not more than 0.5%.

Melting range á741ñ: between 69and 71.

Solubility in sodium hydroxide— Asolution of 500mg in 25mLof 1Nsodium hydroxide is clear or not more than faintly turbid.

Residue on ignition— Ignite 1g with 0.5mLof sulfuric acid:the residue weighs not more than 1mg (0.1%).

Melting range á741ñ: between 51and 53.

Residue on ignition— Ignite 500mg with 5drops of sulfuric acid:the residue weighs not more than 1mg (0.2%).

Melting range á741ñ: between 197and 200.

Solubility in sulfuric acid— Dissolve 500mg in a mixture of 25mLof sulfuric acid and 25mLof water:the solution is clear or not more than slightly turbid.

Residue on ignition(Reagent test): negligible,from 500mg.

Melting range á741ñ: between 26and 28.

Melting range á741ñ: between 192and 194.

Assay— Dissolve about 115mg,accurately weighed,in 30mLof methanol.Slowly add about 20mLof water,heating slightly if necessary for complete solution.Titrate with 0.1Nsodium hydroxide VS,determining the endpoint potentiometrically.Perform a blank determination and make any necessary correction.Each mLof 0.1Nsodium hydroxide is equivalent to 22.73mg of C14H13NO2.Not less than 98.0%is found.

Assay—

Refractive index á831ñ: between 1.495and 1.499at 20.

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 phase G2;the injection port temperature is maintained at 230;the detector temperature is maintained at 300;and the column temperature is maintained at 160and programmed to rise 10per minute to 260.The area of the C10H8N2·HCl peak is not less than 98.5%of the total peak area.

Melting range á741ñ: between 42and 44.

Add the following:

Melting point á741ñ: higher than 300.

Add the following: