Date of Award

Fall 1999

Document Type


Degree Name

Master of Science (MS)


Chemistry & Biochemistry



Committee Director

Edward J. Poziomek

Committee Member

Patricia A. Pleban

Committee Member

Roy L. Williams

Call Number for Print

Special Collections LD4331.C45 T356


Humic substances are of current interest because of their roles in environmental processes involving pollutants. It is also becoming recognized that humic substances may interfere in analysis of environmental samples though the possible adverse effects do not appear to be fully appreciated. The present effort focuses on determining whether humic materials interfere in the analysis of nitrite in water using the Griess reaction. This is a well-known reaction using nitrosation to gjve a diazonium salt followed by coupling with an appropriate reagent to form a dye. This colorimetric method continues to be applied in the laboratory and the field for nitrite. It was found that nitrite analyses at low ppm levels in water may be 50%-60% low in the presence of ppm amounts of specific humic acids. It was shown that the interference is due to molecular association of the Griess dye with the humic acid. The interference results in less color, and with some humic acids, a shift in the wavelength of maximum absorption.


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