an azeotrope comprising desflurane and hydrogen fluoride . the azeotrope can be prepared by fractionally distilling a crude mixture of desflurane and hf . purer desflurane can be readily and easily separated from the azeotrope . it is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader quickly to ascertain the subject matter of the technical disclosure . it is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the appended issued claims .