Packaging and storage—
Preserve in tight cylinders, and prevent exposure to excessive heat.
Identification—
A:
The IR absorption spectrum of it exhibits maxima, among others, at about the following wavelengths, in µm: 3.4 (vs), 6.8 (s), 7.2 (m), and 10.4 (m).
Acidity of residue—
Add 10 mL of water to the residue obtained in the test for
High-boiling residues, mix by swirling for about 30 seconds, add 2 drops of
methyl orange TS, insert the stopper in the tube, and shake vigorously: no pink or red color appears in the aqueous layer.
Limit of sulfur compounds—
Carefully open the container valve to produce a moderate flow of gas. Do not direct the gas stream toward the face, but deflect a portion of the stream toward the nose: the odor is free from the characteristic odor of sulfur compounds.
Assay—
Chromatographic system—
Under typical conditions, the gas chromatograph is equipped with a thermal-conductivity detector and contains a 3-mm × 6-m aluminum column packed with 10 weight percent of liquid phase G30 on nonacid-washed support S1C, helium is used as the carrier gas at a flow rate of 50 mL per minute, and the temperature of the column is maintained at 33
.
System suitability—
The peak responses obtained for n-butane in the chromatograms from duplicate determinations agree within 1%.
Procedure—
Connect 1 Butane cylinder to the chromatograph through a suitable sampling valve and a flow control valve downstream from the sampling valve. Flush the liquid specimen through the sampling valve, taking care to avoid entrapment of gas or air in the sampling valve. Inject a suitable volume, typically 2 µL, of Butane into the chromatograph, and record the chromatogram. Calculate the percentage purity by dividing 100 times the n-butane response by the sum of all of the responses in the chromatogram.
601
), determined at 21