Octadecyl Silane —This reagent is formed in situby reaction of the column support with a suitable silylating agent such as octadecyl trichlorosilane.
Octanophenone, C14H20O—204.31—Colorless liquid.
Assay—
MOBILE PHASE—
Prepare a filtered and degassed mixture of acetonitrile and water (7:3).
PROCEDURE—
Inject about 20µLinto a suitable liquid chromatograph (see Chromatography á621ñ)equipped with a 254-nm detector and a 4.6-mm ×15.0-cm column that contains packing L1.The flow rate is about 2mLper minute.The area of the C14H20Opeak is not less than 99%of the total peak area.
Refractive index á831ñ:
1.5043at 20
.
.
(p-tert-Octylphenoxy)nonaethoxyethanol, C34H62O11—646.85—Use a suitable grade.
[NOTE—Asuitable grade is available commercially as “Tergitol Nonionic NPX,”and as “Triton N101,”from reagent suppliers.]
(p-tert-Octylphenoxy)polyethoxyethanol —Use a suitable grade.
[NOTE—Asuitable grade is available commercially as “Triton 100”from reagent suppliers.]
Octyl Sulfate,Sodium Salt, C8H17O4SNa—232.27—White powder.
Solubility—
A2-g portion dissolves in 100mLof water.
Odorless Absorbent Paper —See Filter Paper,Quantitative.
Olefin 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 in a stabilized form of permanganate.
Measuring range:
0.06to 3.2Vol.–%Propylene,0.04to 2.4Vol.–%Butylene.
Orange G (the sodium salt of azobenzene-betanaphthol disulfonic acid), C6H5N:NC10H4(OH)(SO3Na)2-2,6,8—452.37—Orange to brick-red powder or dark red crystals.Readily soluble in water,yielding an orange-yellow solution;slightly soluble in alcohol;insoluble in ether and in chloroform.The addition of tannic acid TSto its 1in 500solution causes no precipitation (acid color).The addition of hydrochloric acid to a mixture of 500mg of zinc dust and 10mLof its 1in 500solution produces decolorization.When filtered,the colorless filtrate,on standing exposed to air,does not regain its original color (presence of azo-group).When heated,orange Gdoes not deflagrate (distinction from nitro colors).The addition of barium or calcium chloride TSto a concentrated solution of orange Gproduces a colored,crystalline precipitate.The addition of hydrochloric acid to its 1in 500solution produces no change;the addition of sodium hydroxide TSto a similar solution produces a yellowish red to a Bordeaux color but no precipitation.Orange Gdissolves in sulfuric acid with an orange to yellowish-red color.No change in color results upon diluting the solution cautiously with water.
Orcinol (5-Methylresorcinol), C7H8O2·H2O—142.15—White to light tan crystals.
Assay—
Transfer about 60mg,accurately weighed,to a 100-mLvolumetric flask,dissolve in methanol,dilute with methanol to volume,and mix.Transfer 5.0mLof this solution to a 50-mLvolumetric flask and dilute with methanol to volume,and mix.Using a suitable spectrophotometer,1-cm cells,and methanol as the blank,record the absorbance of the solution at the wavelength of maximum absorbance at about 273nm.From the observed absorbance,calculate the absorptivity (see Spectrophotometry and Light-scattering á851ñ):the absorptivity is not less than 13.2,corresponding to not less than 98%of C7H8O2·H2O.
Orthophenanthroline —See 1,10-Phenanthroline.
Osmium Tetroxide (Osmic Acid;Perosmic Anhydride), OsO4—254.23—Use ACSreagent grade.
Oxalic Acid, H2C2O4·2H2O—126.07—Use ACSreagent grade.
3,3¢-Oxydipropionitrile, O(CH2CH2CN)2—124.14—Clear,colorless to slightly yellow liquid.Refractive index:about 1.446at 20
.
Boiling range:
between 174and 176at 10mm of mercury.
and 176at 10mm of mercury.
Oxygen-Helium Certified Standard —Amixture of 1.0%oxygen in industrial grade helium.It is available from most suppliers of specialty gases.