| 摘要 |
A process comprises subjecting 1, 1, 1, 2 - tetrafluoroethane containing organic impurities to at least two distillations. A process comprises subjecting 1, 1, 1, 2 - tetrafluoroethane containing organic impurities to at least two distillations, where the second is conducted under higher pressure than the first one; and separated at the exit from the second distillation process. At least one fraction comprises hydrofluoroalkane, free from organic impurities. Independent claims are also included for: (1) use of 1, 1, 1, 2 - tetrafluoroethane purified by process as claimed as propulsive gas for pharmaceutical aerosols; (2) a method for analysis of organic impurities level of hydro-fluoroalkane comprising gas chromatography conducted at initial temperature up to 40 deg C (preferably up to (-20) deg C), and detection of impurities by mass spectrometry, using SIM (selected ion monitoring) or TOF (time of flight) mode; (3) a process for production of hydrofluoroalkane, using purification process and method of analysis as claimed as means of quality control; (4) a process for producing pharmaceutical aerosols containing at least one hydrofluoroalkane of pharmaceutical quality, using quality control method as claimed; (5) production of purified hydrofluoroalkane selected from 1, 1, 1, 2, 3, 3, 3 - heptafluoropropane, 1, 1, 1, 3, 3 - pentafluoro-propane and 1, 1, 1, 3, 3 - pentafluorobutane, using 2-stage distillation process as claimed; and (6) purified hydrofluoroalkane with molar content of each organic impurity below 10 ppm.
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