EVALUATING GEOCHEMISTRY FIELD TEST KITS

This study focused evaluating two field test kits (Exact Micro 20 and the Hach Spectrophotometer) used to test water quality and comparing it to ion chromatograph (IC). These field test kits are commonly used in the field to determine if water needs further testing or when working in isolated areas (low-income countries) where access to IC is limited. It is important that these kits be accurate if they are to be used to indicate whether water is safe to use. In order to do this, three Exact Micro 20s, one Hach Odyssey Spectrophotometer, and an ion chromatograph were tested using known concentrations made from an anion standard for nitrate, nitrite, phosphate, sulfate, fluoride and chloride. Each field test kit tested each level of concentration for each substance in the concentration three times, the ion chromatograph ran once with each level of concentration. Preliminary results show some variation in accuracy between substance and level of concentration. It is likely 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. This research will be continued in more detail and will be useful for those relying on the test kits to understand the water quality of anywhere.