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Apparatus and technique for multiple tests by the confined-spot method of colorimetric analysis: Application to field estimation of nickel and copper

January 1, 1958

The confined-spot method of colorimetric analysis is generally applicable to the semiquantitative estimation of traces of ions in solution that form colored precipitates or otherwise alter material on a confined area of reagent paper. For precise results, the rate of flow of test solutions through the reagent paper must be reproduced on successive runs, so that the same proportion of reaction products is collected each time on the confined spot. A simple apparatus gives a controlled rate of flow and makes possible the analysis of many samples at one time with good reproducibility. This apparatus utilizes the increasing pull, resulting from the gradual lowering of the water level in a tank, to draw a sample solution through a confined area of reagent paper at a reproducible rate. Application to the rapid determination of nickel with dimethylglyoxime and of copper with rubeanic acid provides a method for determination of as little as 0.06 γ of nickel and 0.03 γ of copper. The coefficients of variation are 14 and 22%, respectively. This method has wide applicability in more rapid and convenient determination of trace amounts of many metals.

Citation Information

Publication Year 1958
Title Apparatus and technique for multiple tests by the confined-spot method of colorimetric analysis: Application to field estimation of nickel and copper
DOI 10.1021/ac60136a026
Authors J. H. McCarthy, R. E. Stevens
Publication Type Article
Publication Subtype Journal Article
Series Title Analytical Chemistry
Series Number
Index ID 70010451
Record Source USGS Publications Warehouse
USGS Organization