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1998
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In the Laboratory
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Bilinear Regression Analysis as a Means To Reduce Matrix Effects in Simultaneous Spectrophotometric Determination of Cr(III) and Co(II): AQuantitative Analysis Laboratory Experiment
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Siddharth Pandey, Mary E. R. McHale, Karen S. Coym, and William E. Acree Jr.
University of North Texas, Department of Chemistry, P.O. Box 5068, Denton, TX 76203-5070
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July 1998
Vol. 75 No. 7
p. 878
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| Abstract |
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An undergraduate laboratory experiment is designed for the simultaneous determination of both Co(II) and Cr(III) in unknown liquid mixtures based upon a bilinear least squares regressional analysis of measured absorbance data. Unlike several published laboratory experiments, in our method standard solutions contain both ions. Numerical values of the four molar absorpti-vities are calculated from a least squares of analysis of the Beer-Lambert law expression for two light-absorbing species. From an educational standpoint, our modification gives students greater exposure to standard curve-fitting techniques and provides a convenient means to introduce computer programming and/or spreadsheet computations into the laboratory portion of the course. Cobalt (II) and chromium (III) concentrations determined using the bilinear regression method fall within 1-2 % of the correct values.
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| More Information |
 Citation |
Pandey, Siddharth; McHale, Mary E. R.; Coym, Karen S.; Acree, William E., Jr. J. Chem. Educ. 1998 75 878.
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Keywords |
Laboratory Instruction, Quantitative Analysis, Spectroscopy, UV-Vis Spectroscopy, Analytical Chemistry
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History |
Created:
Last Updated: |
June 22, 1999
June 24, 2005
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| Home > JCE Print > Journal of Chemical Education > Issues >
1998
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878
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