Packaging and storage
Preserve in tight cylinders, and avoid exposure to excessive heat.
The IR absorption spectrum of it, determined in a 10-cm cell with sodium chloride windows, at atmospheric pressure, exhibits maxima, among others, at the following wavelengths, in µm: 4.67 (m), 5.95 (m), 7.28 (s), 8.06 (m), 9.2 (vs), 10.7 (vs), 11.8 (vs), and 13.4 (m). The stronger maxima are best obtained at pressures less than 10 mm of mercury.
In the chromatogram recorded for the Assay
, identify the peaks due to dichlorodifluoromethane and dichlorotetrafluoroethane from relative retention times observed on chromatographing the Resolution preparation:
the sum of these two peak areas is not greater than 0.2% of the total of all peak areas; and the sum of the areas of all peaks other than that for trichloromonofluoromethane is not greater than 0.4% of the total of all peak areas.
Place 5 mL of anhydrous methanol in a test tube, add 3 drops of a saturated solution of silver nitrate in anhydrous methanol, shake, and add 7 g of Trichloromonofluoromethane: no opalescence or turbidity is produced.
Introduce the liquid phase of Trichloromonofluoromethane into an evacuated headspace vial.
Inject the gas phase headspace Assay preparation into the chromatograph, record the chromatogram, and measure the peak areas. Calculate the percentage (a/a) of CCl3F in the portion of Trichloromonofluoromethane taken.
: Daniel K. Bempong, Ph.D., Scientist
Expert Committee : (MDPS05) Monograph Development-Pulmonary and Steroids
USP29NF24 Page 3451
: Volume No. 27(1) Page 1825
Phone Number : 1-301-816-8143