Evaluation of test kits for sustainable water management in changing conditions

ABSTRACT On-site chemical analysis using test kits is essential for water analysis and management, especially in changing conditions. It is important to propose the procedure for the evaluation of test kits, i.e. determining the quality of the results they provide. In the present work, we have used the diagnostic tests evaluation approach to determine the metrological characteristics of colorimetric water test kits. Each color and the assigned concentration on the test kit color scale is treated as a binary classifier. This approach allowed calculating the metrological characteristics of 11 test kits for water analysis produced by the SIA MedEcoTest (Riga, Latvia). The results show that sensitivity, specificity, and precision are in the range of 80–100%. The metrological parameter values do not depend on the color of the test kit reaction used (p-values of 0.4–0.9). The test kits for higher concentration ranges demonstrate higher sensitivity than the test kits for lower ranges, but the specificity is not affected.