Abstract: Provided are a standard sample film or a standard sample for use in laser ablation inductively coupled plasma mass spectrometry, the standard sample film or the standard sample containing an organic substance and having a small variation in signal intensity of an ion of a metal element depending on a measurement position; a method for producing a standard sample film; a sample set; a quantitative analysis method; and a transfer film. The standard sample film of the present invention is a standard sample film for use in laser ablation inductively coupled plasma mass spectrometry, the standard sample film containing a polymer, a metal element, and an internal standard, and having a maximum height difference in film thickness of the standard sample film of 0.50 ?m or less.

Abstract: A process for extracting and separating silver safely and selectively from a raw material containing slightly soluble silver compounds and recovering silver from the extract in a simple manner without resorting to electrolysis or a special reducing agent, and further recovering high-purity silver, includes mixing the raw material with an organic solvent solution of an organophosphorus compound containing in the molecule sulfur in the form of S.sup.2- ions, thereby extracting silver into an organic phase simultaneously with dissolving the slightly soluble silver compounds, stripping the silver from the organic phase containing the extracted silver with an aqueous solution of alkali sulfite and forming a stripping solution, and reducing the stripping solution to separate silver therefrom.