C2Cl2F4 170.92

Ethane,1,2-dichloro-1,1,2,2-tetrafluoro-.
1,2-Dichlorotetrafluoroethane [76-14-2].

Packaging and storage— Preserve in tight cylinders,and avoid exposure to excessive heat.

Identification— The IRabsorption 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:4.34(s),4.48(m),5.28(m),5.95(m),7.36(s),9.5(vs),10.9(vs),11.8(vs),13.6(s),and 14.8(s).The stronger maxima are best obtained at pressures less than 10mm of mercury.

Boiling temperature: approximately 4,determined as directed under Approximate Boiling Temperature (see Aerosols,Nasal Sprays,Metered-Dose Inhalers,and Dry Powder Inhalers á601ñ).

Water: not more than 0.001%,determined as directed under Water Content (see Aerosols,Nasal Sprays,Metered-Dose Inhalers,and Dry Powder Inhalers á601ñ).

High-boiling residues: not more than 0.01%,determined as directed for High-Boiling Residues,Method I,under Aerosols,Nasal Sprays,Metered-Dose Inhalers,and Dry Powder Inhalers á601ñ.

Chromatographic purity— In the chromatogram recorded for the Assay,identify the peaks due to dichlorodifluoromethane and trichloromonofluoromethane 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 dichlorotetrafluoroethane is not greater than 0.4%of the total of all peak areas.

Inorganic chlorides— Place 5mLof anhydrous methanol in a test tube,add 3drops of a saturated solution of silver nitrate in anhydrous methanol,shake,and add 7g of Dichlorotetrafluoroethane:no opalescence or turbidity is produced.

Assay—

Expert Committee:(PA1)Pharmaceutical Analysis 1

USP28–NF23Page 2998

Phone Number:1-301-816-8379