Evaluating the Accuracy of Hydrogeological Field Test Kits

Session Number

Project ID: ERSP 2

Advisor(s)

Dr. Melissa Lenczewski; Northern Illinois University

Discipline

Earth and Space Sciences

Start Date

22-4-2020 10:05 AM

End Date

22-4-2020 10:20 AM

Abstract

Research the effectiveness of several hydrogeological field test kits, including the Hach Spectrophotometer, and the Exact Micro 20.

In this study, three Exact Micro 20s and one Hach Odyssey Spectrophotometer were tested using five solutions of known concentrations made by mixing anion standards of nitrate, nitrite, sulfate, phosphate, fluoride and chloride with deionized water. Each field test kit was used to measure the concentration of each substance in each of the standardized solutions three times. An ion chromatograph was used once with each standardized solution to confirm the calculated concentration.

The results of this study indicate that the accuracy of a test kit depends on the substance being tested and proximity of the concentration to the low and high levels of the testing range. Specifically, the kit test results were less accurate for nitrate, nitrite and chloride and when the concentration present was close to the limits of the test kits’ stated detection limits. This research should be continued by testing cations, and taking more data for anions, and will be useful for those relying on the test kits to understand the quality of water as measured in the field, since these test kits have not previously been evaluated.

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Apr 22nd, 10:05 AM Apr 22nd, 10:20 AM

Evaluating the Accuracy of Hydrogeological Field Test Kits

Research the effectiveness of several hydrogeological field test kits, including the Hach Spectrophotometer, and the Exact Micro 20.

In this study, three Exact Micro 20s and one Hach Odyssey Spectrophotometer were tested using five solutions of known concentrations made by mixing anion standards of nitrate, nitrite, sulfate, phosphate, fluoride and chloride with deionized water. Each field test kit was used to measure the concentration of each substance in each of the standardized solutions three times. An ion chromatograph was used once with each standardized solution to confirm the calculated concentration.

The results of this study indicate that the accuracy of a test kit depends on the substance being tested and proximity of the concentration to the low and high levels of the testing range. Specifically, the kit test results were less accurate for nitrate, nitrite and chloride and when the concentration present was close to the limits of the test kits’ stated detection limits. This research should be continued by testing cations, and taking more data for anions, and will be useful for those relying on the test kits to understand the quality of water as measured in the field, since these test kits have not previously been evaluated.