Diclofenac analysis in natural waters using UV-visible absorption spectrometric method

In this work, we developed an UV-visible (UV-VIS) absorption spectrometric method for the quantification of sodium diclofenac in natural waters. Several UV-VIS absorption method parameters were optimized. The maximum absorption wavelength was comprised between 276 and 292 nm, depending on the solvent, with molar absorption coefficients greater than 104 L mol-1 cm-1. The linearity of the UV-VIS calibration curves extended over one to three orders of magnitude, with correlation coefficients (R2) very close to unity. The low relative standard deviation (RSD)  values indicated a good reproducibility of the measurements. Analytical applications to natural waters yielded satisfactory results with average recovery rates between 94.7 and 99.1%.