Olefin Detector Tube
A fuse-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.
0.06 to 3.2 Vol.% Propylene, 0.04 to 2.4 Vol.% Butylene.
(the sodium salt of azobenzene-betanaphthol disulfonic acid
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 TS
to its 1 in 500 solution causes no precipitation (acid color
). The addition of hydrochloric acid to a mixture of 500 mg of zinc dust and 10 mL of its 1 in 500 solution 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 G does not deflagrate (distinction from nitro colors
). The addition of barium or calcium chloride TS to a concentrated solution of orange G produces a colored, crystalline precipitate. The addition of hydrochloric acid to its 1 in 500 solution produces no change; the addition of sodium hydroxide TS
to a similar solution produces a yellowish red to a Bordeaux color but no precipitation. Orange G dissolves in sulfuric acid with an orange to yellowish-red color. No change in color results upon diluting the solution cautiously with water.
White to light tan crystals.
Transfer about 60 mg, accurately weighed, to a 100-mL volumetric flask, dissolve in methanol, dilute with methanol to volume, and mix. Transfer 5.0 mL of this solution to a 50-mL volumetric 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 273 nm. From the observed absorbance, calculate the absorptivity (see Spectrophotometry and Light-scattering 851
): the absorptivity is not less than 13.2, corresponding to not less than 98% of C7