Method and system for X-ray fluorescence (XRF) analysis of exploration samples

A collector device for determining a metal in an exploration sample containing a concentration of the metal not directly detectable by X-ray fluorescence (XRF) is disclosed. The collector device comprises an adsorbent material capable of concentrating metal from a digestion mixture produced by digesting the exploration sample, wherein the adsorbent material is configured for association with an analysis window of the XRF detector to facilitate determination by the XRF detector of the amount of metal value in the exploration sample. A sample preparation vessel, method and system which may be used to prepare exploration samples for metal analysis is also disclosed. Said vessel includes a vessel for receiving the exploration sample, a digestion composition or a digestion tablet, and a digestion medium; a closure for the vessel to allow the vessel to be agitated and thereby produce a digestion mixture comprising dissolved metal and the collector device as described above. The closure and the collector device are coupled in a manner whereby the collector device is retrieved from the vessel by removing the closure therefrom. The digestion composition and the digestion tablet include a metal lixiviant and an alkali compound and may further include an accelerant and/or a pH indicator.