Abstract: Improvement to the process of elementary analysis of a specimen by high frequency inductively coupled plasma mass spectrometry, by means of an apparatus including a torch for producing plasma from a plasma producing medium and for injecting the specimen in this plasma and an interface for taking a sample in the specimen, comprising two consecutive conical members disposed along the same axis except that the conical members have angles with different apices and are each provided with an axial orifice enabling a fraction of the specimen to be analyzed to pass therethrough. According to the invention, a given quantity of a make-up gas is added to the specimen which is injected into the plasma, the make-up gas having a high heat producing power, so as to raise the temperature of the plasma for locally heating the sampling conical members thereby preventing the components of the specimen which are present in the plasma from depositing on the conical members.

Abstract: A process for the preparation of metal fluorides usable for the production of fluoride glasses consists of reacting in an organic liquid medium, such as toluene, (a) a compound of said metal chosen from among the gaseous compounds thereof, the compounds of said metal soluble in the organic liquid medium and the compounds of said metal in solution in an organic solvent miscible with said medium, and (b) a fluorinating agent chosen from among the gaseous fluorinating agents, the fluorinating agents which are partly soluble in the organic medium and the fluorinating agents which are partly soluble in an organic solvent miscible with said medium, to form a fluoride of said metal, the organic liquid medium being such that it reacts neither with the compound of the metal, nor with the fluorinating agent and does not dissolve the fluoride formed. To prepare the zirconium tetrafluoride, it is possible to introduce in toluene, gaseous Zr(BH.sub.4).sub.