Quantitative and selective ion measurement - uses an adsorption medium which is washed with a reagent for chromatography and photometer detection

摘要

To give a quantitative selective count of one or more ions present in metallic or cpd. types of the same metal as a soln. for analysis, the soln. is passed through an absorption medium which only absorbs those ions to be detected. The ions are washed from the absorption medium by a flow medium which contains a reagent which, by chemical reaction, forms a specific recognisable compound. The wash is treated by chromatography to separate the materials dissolved in its content, for the chromatographed wash to be examined by a detector. The concn. of the ions is determined by applying the detected measurements to a characteristic chemo-physical value. Pref. before the absorption medium is washed, the unabsorbed analysis soln. is washed clear with deionised water. The recognisable cpd. is a characteristic coloured cpd. for a photo-meter detector to give a measured value with a characteristic extinction coefft. for the cpd. An acid rhodanide soln. is pref. for washing ions from the absorption medium. The photometer detector works with characteristic wavelengths for Cu and/or ferrous rhodanide complexes. An acid ion exchanger is used as the absorption medium, or it is a semiconductor of Si or a fixed Si cpd. The pref. reagent is PAR (4-(2-pyridylazo) resorcin). The ion concn. is determined by comparison with the extinction coefft. of various concd. calibrating solns. USE/ADVANTAGE - The technique is for the analsyis of ions in the semiconductor industry, where disruptive ions could affect the material performance. The process gives a quantitative and selective measurement of ions in solns. with a concn. of 10 power (-6) g/litre.