Hematein, C16H12O6—300.26—Prepared from logwood extract or from hematoxylin by treatment with ammonia and exposure to air.Reddish-brown crystals with a yellowish-green metallic luster.Very slightly soluble in water (about 1in 1700);slightly soluble in alcohol and in ether;insoluble in benzene and in chloroform;freely soluble in diluted ammonia solution to form a solution of dusky purplish red color and in an aqueous solution of sodium hydroxide (1in 50),to form a solution of bright red color,viewed in each case through a layer 1cm in depth.Melts at a temperature above 200
and tends to decompose at 250.
Hematoxylin (Hydroxybrasilin), C16H14O6.3H2O—356.32—Acrystalline substance derived from the heart-wood of Haematoxylon campechianumLinné(Fam.Leguminosae).Colorless to yellow prisms.Very slightly soluble in cold water and in ether;rapidly soluble in hot water and in hot alcohol.When exposed to light,it acquires a red color and yields a yellow solution.Dissolves in ammonia TSand in solutions of alkali hydroxides and carbonates.When dissolved in solutions of the following salts,it develops the colors indicated:in alum solution a red color;in stannous chloride solution a rose color;in solutions of cupric salts a greenish-gray color.It gradually turns black in potassium dichromate solution.Store hematoxylin and its solutions protected from light and air.
Hemoglobin,Bovine— [9008-02-0]—Use a suitable grade.
[NOTE—Asuitable grade is available as Bovine Hemoglobin substrate powder from Sigma-Aldrich,www.sigma-aldrich.com.]
1-Heptadecanol, C17H36O—256.48[1454-85-9]—Use a suitable grade.
Heptafluorobutyric Acid, C4F7O2H—214.04[375-22-4]—Use a suitable grade.
n-Heptane —Use n-Heptane,Chromatographic.
n-Heptane,Chromatographic —Clear,colorless,volatile,flammable liquid consisting essentially of C7H16.It has a characteristic odor.Practically insoluble in water;soluble in absolute alcohol.Miscible with ether,with chloroform,with benzene,and with most fixed and volatile oils. [NOTE—n-Heptane may require purification by passage through a column of silica gel,a ratio of about 25g of the gel for each 100mLof n-heptane being used,and subsequent fractional distillation.]
Boiling range(Reagent test):
between 94.5and 99.0.
and 99.0.
Spectral purity—
Measure in a 1-cm cell at 250nm,with a suitable spectrophotometer,against water as the blank:its absorbance is not more than 0.10.
Residue on evaporation—
It meets the requirements of the test for Residue on evaporationunder Hexane,Solvent.
Hexadecyl Hexadecanoate (Hexadecyl Palmitate;Cetyl Palmitate), C32H64O2—480.85—Use a suitable grade.
[NOTE—Suitable grades are available commercially as Hexadecyl Palmitate,and Palmitic Acid Palmityl Ester from Sigma-Aldrich,www.sigma-aldrich.comand Cetyl Palmitate,Catalog number C1203,from Spectrum Chemical Mfg.Corp.,www.spectrumchemical.com.]
Hexamethyldisilazane, C6H19NSi2—161.39—Clear,colorless liquid,having a characteristic odor.
Assay—
When examined by gas-liquid chromatography,it shows a purity of not less than 95%.The following conditions have been found suitable for assaying the article:A2-mm ×1.8-m glass column packed with phase G3on support S1.Helium,flowing at a rate of about 40mLper minute,is the carrier gas,the detector temperature is about 310,the injection port temperature is about 100,and the column temperature is programmed to start at 35,hold for 5minutes,then rise at a rate of 8per minute to 200.Aflame-ionization detector is employed.
,the injection port temperature is about 100,and the column temperature is programmed to start at 35,hold for 5minutes,then rise at a rate of 8per minute to 200.Aflame-ionization detector is employed.
Residue after evaporation—
Transfer 200g to a tared dish,and evaporate on a steam bath to dryness.Dry the residue at 105for 1hour,cool,and weigh:not more than 0.0025%of residue is found.
for 1hour,cool,and weigh:not more than 0.0025%of residue is found.
Hexamethyleneimine (Homopiperidine), C6H12NH—99.17—Colorless to nearly colorless liquid.
Refractive index á831ñ:
between 1.4640and 1.4660at 20.
.
n-Hexane, C6H14—86.18(for use in spectrophotometry)—Use Hexanes.
Hexane,Solvent (Petroleum Benzin;Petroleum Ether) —Clear,volatile liquid,having an ethereal or faint,petroleum-like odor.Practically insoluble in water;soluble in absolute alcohol.Miscible with ether,with chloroform,with benzene,and with most fixed and volatile oils.[Caution—It is dangerously flammable.Keep it away from flames and store in tight containers in a cool place. ]
Appearance and color—
Pour 100mL,previously well-mixed in its original container,into a 100-mLcolor-comparison tube,and compare with a standard,in a similar tube,containing 2mLof platinum-cobalt TSin similar volume:the two liquids are equally clear and free from suspended matter or sediment and when viewed across the columns by transmitted light,the test specimen is not darker in color than the standard.
Odor—
Its odor is not disagreeable or suggestive of mercaptans or thiophene.
Distilling range(Reagent test)—
Distill 100mL:none distils below 30and not less than 100%distils between 30and 60.
and not less than 100%distils between 30and 60.
Residue on evaporation—
Evaporate 150mL(100g)on a steam bath,and dry at 105for 30minutes:the residue weighs not more than 1mg (0.001%).
for 30minutes:the residue weighs not more than 1mg (0.001%).
Acidity—
Shake 10mLwith 5mLof water for 2minutes,and allow the layers to separate:the water layer does not turn blue litmus red within 15seconds.
Heavy oils and fats—
Gradually pour 10mLonto the center of a clean filter paper:there is no disagreeable odor and no greasy stain visible on the paper after it has stood for 30minutes.
Hexane,Solvent,Chromatographic —It complies with the specifications for Hexane,Solvent,and meets the requirements of the following additional test.
Spectral purity—
Measure in a 1-cm cell at 300nm,with a suitable spectrophotometer,against air as the blank:its absorbance is not more than 0.08.
Hexanes (suitable for use in UVspectrophotometry);usually a mixture of several isomers of hexane (C6H14),predominantly n-hexane,and methylcyclopentane (C6H12)—Use ACSreagent grade.
Hexanitrodiphenylamine (Dipicrylamine), C12H5N7O12—439.21—Yellow-gold powder or prisms.Explosive.Usually contains about 15%of water as a safety precaution.Insoluble in water,in alcohol,in acetone,and in ether;soluble in glacial acetic acid and in alkalies.
Water,Method Iá921ñ:
not more than 16%.
Hexanophenone, C12H16O—176.25—Yellow liquid.
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 a 1-µm layer of phase G3;the injection port temperature is maintained at 280;the detector temperature is maintained at 300;the column temperature is maintained at 180and programmed to rise 10per minute to 280.The area of the C12H16Opeak is not less than 98%of the total peak area.
;the detector temperature is maintained at 300;the column temperature is maintained at 180and programmed to rise 10per minute to 280.The area of the C12H16Opeak is not less than 98%of the total peak area.
Refractive index á831ñ:
1.511±0.002at 20.
.
Horseradish Peroxidase Conjugated to Goat Anti-Mouse IgG— Affinity purified polyclonal antibody to Mouse Immune globulin (IgG)heavy and light chains (whole IgG)produced in Goat and labeled with horseradish peroxidase.Available either as a lyophilized powder or as a solution in a suitable buffer,generally 10mMsodium phosphate,pH7.4,containing a suitable preservative,such as 0.01%thimerosal,and an inactive protein(s)to prevent adsorption on the surface of the container.Use a suitable grade.Store at –20
.
Hydrazine Hydrate,85%in Water, (NH2)2·H2O—50.06—Colorless liquid.
Assay—
Transfer 600mg,accurately weighed,to a 100-mLvolumetric flask.Dilute with water to volume,and mix.Pipet 10mLinto a suitable beaker,add 1.0g of sodium bicarbonate and 50.0mLof 0.1Niodine VS.Titrate the excess iodine with 0.1Nsodium thiosulfate VS,using starch TSas the indicator.Perform a blank determination,and make any necessary correction.Each mLof 0.1Niodine is equivalent to 12.52mg of (NH2)2·H2O.Not less than 83%is found.
Hydrazine Dihydrochloride, (NH2)2·2HCl—104.97—White powder.
Assay—
Dissolve about 34mg,accurately weighed,in 50mLof water.Add carefully while stirring,1g of sodium bicarbonate.[Caution—There may be a rapid evolution of carbon dioxide.
]Titrate with 0.1Niodine solution,determining the endpoint potentiometrically.Perform a blank determination,and make any necessary corrections.Each mLof 0.1Niodine solution is equivalent to 2.63mg of (NH2)2·2HCl.Not less than 98%is found.
Hydrazine Sulfate, (NH2)2·H2SO4—130.12[10034-93-2]—Use ACSreagent grade.[Caution—Great care should be taken in handling hydrazine sulfate because it is a suspected carcinogen. ]
Hydrindantin (2,2¢-Dihydroxy-2,2¢-biindan-1,1¢,3,3¢-tetrone), C18H10O6—322.27[5103-42-4]—Sparingly soluble in hot water;soluble in methoxyethanol.When heated above 200
,it becomes reddish brown.
Hydriodic Acid, HI—127.91—Use ACSreagent grade (containing not less than 47.0%of HI).
[NOTE—For methoxy determination (see Methoxy Determination á431ñ),use hydriodic acid ACSreagent grade 55%.Use this grade also for alkoxyl determinations in assays in the individual monographs.]
Hydrochloric Acid, HCl—36.46—Use ACSreagent grade.
Hydrochloric Acid,Diluted (10percent)—Prepare by mixing 226mLof hydrochloric acid with sufficient water to make 1000mL.
Hydrofluoric Acid, HF—20.01—Use ACSreagent grade.
Hydrogen Peroxide,30Percent, H2O2—34.01—Use ACSreagent grade.
Hydrogen Peroxide Solution —Use Hydrogen Peroxide Topical Solution.
Hydrogen Sulfide, H2S—34.08—Colorless,poisonous gas,heavier than air.Soluble in water.Is generated by treating ferrous sulfide with diluted sulfuric or diluted hydrochloric acid.Other sulfides yielding hydrogen sulfide with diluted acids may be used.Is also available in compressed form in cylinders.
Hydrogen Sulfide Detector Tube— Afuse-sealed glass tube so designed that gas may be passed through it and containing suitable absorbing filters and support media for the indicator,the latter consisting of a suitable lead salt.
Measuring range:
1to 20ppm.
[NOTE—Available from Draeger Safety,Inc.,www.draeger.com,or from Gastec Corp.,www.gastec.co.jp,distributed in the USAby www.nextteq.com.]
Hydroquinone, C6H4(OH)2—110.11—Fine,colorless or white,needle crystals.Darkens on exposure to air and light.Soluble in water,in alcohol,and in ether.
Assay—
Accurately weigh about 250mg,and dissolve in a mixture of 100mLof water and 10mLof 0.1Nsulfuric acid in a 250-mLconical flask.Add 3drops of a 1in 100solution of diphenylamine in sulfuric acid,and titrate with 0.1Nceric sulfate VSuntil the solution is red-violet in color.Each mLof 0.1Nceric sulfate is equivalent to 5.506mg of C6H4(OH)2.Not less than 99%is found.
3¢-Hydroxyacetophenone, C8H8O2—136.15—Light brown powder chips and chunks.Melts at about 96
.Sparingly soluble in chloroform,yielding a clear,light yellow solution.
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 G1;the detector and the injection port temperature are maintained at 300;the column temperature is maintained at 180and programmed to rise 10per minute to 280and held at that temperature for 10minutes.The area of the main peak is not less than 97%of the total peak area.
;the column temperature is maintained at 180and programmed to rise 10per minute to 280and held at that temperature for 10minutes.The area of the main peak is not less than 97%of the total peak area.
4¢-Hydroxyacetophenone, HOC6H4COCH3—136.15—Gray powder,melting at about 109
.
p-Hydroxybenzoic Acid, C7H6O3—138.12—White crystals.
Assay—
Transfer about 700mg,accurately weighed,to a suitable container,and dissolve in 50mLof acetone.Add 100mLof water,mix,and titrate with 0.5Nsodium hydroxide VS,determining the endpoint potentiometrically.Perform a blank determination,and make any necessary correction.Each mLof 0.5Nsodium hydroxide is equivalent to 69.06mg of C7H6O3:not less than 97%is found.
4-Hydroxybenzoic Acid Isopropyl Ester, HOC6H4COOCH(CH2)2—180.18—Use a suitable grade.
1-Hydroxybenzotriazole Hydrate, C6H5N3O·xH2O—135.13(anhydrous)—White,crystalline powder.Sparingly soluble in alcohol yielding a clear,pale yellow solution.
2-Hydroxybenzyl Alcohol, C7H8O2—124.14—Off-white flakes.Very soluble in alcohol,in chloroform,and in ether;soluble in 15parts water and in benzene.
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 C7H8O2peak is not less than 99%of the total peak area.
;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 C7H8O2peak is not less than 99%of the total peak area.
N-(2-Hydroxyethyl)piperazine-N'-(2-ethanesulfonic acid), C8H18N2O4S—238.3[7365-45-9]—Use a suitable grade.
4-Hydroxyisophthalic Acid, C8H6O4—182.13—Colorless branched needles.Freely soluble in alcohol and in ether.
Hydroxylamine Hydrochloride, NH2OH·HCl—69.49—Use ACSreagent grade.
Hydroxy Naphthol Blue (1-(2-Naphtholazo-3,6-disulfonic Acid)-2-naphthol-4-sulfonic acid,disodium salt),C20H12N2O11S3Na2—598.50—Deposited on crystals of sodium chloride in the concentration of about 1%.Use ACSreagent grade.
10b-Hydroxynorandrostenedione (10b-Hydroxy-19-norandrost-4-ene-3,17-dione), C18H24O3—288.38—Use a suitable grade.
3-Hydroxyphenyldimethylethyl Ammonium Chloride [Dimethylethyl(3-hydroxyphenyl)ammonium Chloride]—Use Edrophonium Chloride.
D-a-4-Hydroxyphenylglycine, C8H9NO3—167.16—Shiny leaflets.Sparingly soluble in water,in alcohol,in acetone,in ether,in chloroform,in ethyl acetate,in benzene,and in glacial acetic acid;soluble in alkalies and in mineral acids;freely soluble in warm 20%v/v hydrochloric acid.
4-(4-Hydroxyphenyl)-2-butanone, C10H12O2—164.20—White powder.
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 G43;the injection port temperature is maintained at 280;the detector temperature is maintained at 300;the column temperature is maintained at 180and programmed to rise 10per minute to 280.The area of the C10H12O2peak is not less than 98.5%of the total peak area.
;the detector temperature is maintained at 300;the column temperature is maintained at 180and programmed to rise 10per minute to 280.The area of the C10H12O2peak is not less than 98.5%of the total peak area.
8-Hydroxyquinoline (Oxine), C9H7NO—145.16—Use ACSreagent grade 8-Quinolinol.
Hypophosphorous Acid,50Percent (Hypophosphorous Acid), HPH2O2—66.00—Acolorless to faintly yellow liquid.Miscible with water and with alcohol.
Assay—
Accurately weigh about 4mL,dilute with 25mLof water,add methyl red TS,and titrate with 1Nsodium hydroxide VS:each mLof 1Nsodium hydroxide is equivalent to 66.00mg of HPH2O2.Not less than 48%is found.
Chloride—
Add 0.2mLto a mixture of 10mLof silver nitrate TSand 5mLof nitric acid,and heat until brown fumes are no longer evolved:any white,insoluble residue remaining is negligible.
Phosphate—
Dilute 1mLwith water to 50mL,render alkaline with ammonia TS,filter if a precipitate is formed,and add to the filtrate 5mLof magnesia mixture TS:not more than a slight precipitate is formed within 5minutes.
Sulfate(Reagent test,Method I)—
Dilute 1mLwith water to 50mL:20mLof the solution shows not more than 0.2mg of SO4.
Hypoxanthine, C5H4N4O—136.11[68-94-0]—White to yellowish-white powder.Soluble in 1Nsodium hydroxide.Use a suitable grade.