Abstract: This invention relates introduction of at least one additive for the analysis of at least one substance of interest using a mass spectrometer or an ion mobility spectrometer. The substance to be analyzed is injected through an API interface. The additive is introduced by adding spray gas.

Abstract: The invention relates to an electrocatalytic or aero-electrocatalytic process for the reducing dissolving of a refractory compound of cerium such as CeO.sub.2. According to this process, the compound to be dissolved is introduced into an aqueous acid solution, e.g. a sulphuric solution, containing an electrochemical carrier constituted by one of the reducing or oxidizing species of a redox pair, whose redox potential is below +1.25 V/SHE, e.g. a ferric salt, a uranyl salt, molecular iodine or oxygen, and continuous generation and/or regeneration takes place by electrolysis of the reducing species of said redox pair.

Abstract: A process for reducing and dissolving PuO.sub.2 comprises contacting the plutonium dioxide with a hydrazine-free, acid aqueous solution containing a reducing agent, whose redox potential is below +0.5 V/ENH in order to reduce and dissolve the plutonium. The reducing agent can be Cr.sup.2+ or U.sup.4+.