Determination of Ethylenediaminetetraacetic acid (EDTA) levels in surface waters by high performance liquid chromatography (HPLC)-Ultraviolet/Visible (UV/VIS) detector

Abstract

Ethylenediaminetetraacetic acid (EDTA) is a chemical that is harmful to human health with its high solubility in water, which is used as a metal chelating agent in industries such as medicine, food, personal care product, agriculture. Thus, it is necessary to should be monitored in surface waters taken from dams supplying drinking and utility water. This work presents the applicability of the HPLC-UV/VIS system for the quantification of EDTA in surface waters based on the limit values of national and international legislation such as the Turkish Regulation on the Management of Surface Water Quality. The applicability of EDTA quantification in surface water was checked with validation study. The method validation consisted of selectivity, calibration curve linearity, limit of detection (LOD) and limit of quantification (LOQ), accuracy (recovery), and precision. In selectivity study, no peaks belonging to interfering compounds that would cause false-positive results were found in the chromatograms at the retention time of EDTA (5.773 min.). The linearity of EDTA was obtained ranging from 10 µg/L to 200 µg/L concentrations with the correlation coefficient of 0.9985 and the calibration curve equation of y=4659.4x-50223. The LOD and LOQ values of EDTA was 2.85 µg/L and 9.51 µg/L with the RSD of 5.36. In accuracy, the mean recovery of EDTA in surface water has been determined as 87.51 percent with an RSD of 6.11. The repeatability (RSD, %) varied from 5.44 % to 7.02 % with concentrations of 35.19 ± 1.91 μg/L and 17.11 ± 1.20 μg/L, whereas the reproducibility (RSD, %) was obtained at 3.45 % with the concentration of 34.13 ± 1.18 μg/L. In this study, the presence of EDTA was investigated in approximately 300 surface water samples and EDTA was found as positive in the concentration range of 11.17 µg/L to 52.14 µg/L in eleven real samples.