Development and validation of a simple and rapid analytical method for the micropollutant 2,4-DTBP using RP-UHPLC/DAD in synthetic aqueous solutions and municipal wastewater

Abstract

A new, simple, and rapid analytical method using the RP-UHPLC/DAD system and external calibration strategy was developed to quantify 2,4-Di-tert-butylphénol (2,4-DTBP) in wastewater. Three municipal wastewater samples collected from three pumping stations (SP1, SP2 and SP3) over three days at different times were analyzed. The RP-UHPLC/DAD system's suitability and the developed method were assessed using a 2,4-DTBP standard solution (1.5µg/mL). Validation involved checking the analyte's maximum absorbance at a wavelength of 228.81nm. The dynamic range tested (0.2, 0.4, 0.8, 1.6, 3.2, and 6.4µg/mL) showed a correlation coefficient (r²) of 0.999. Validation parameters such as linearity, accuracy, precision, limit of detection (LOD), limit of quantification (LOQ), and robustness were confirmed. Recovery experiments with synthetic aqueous solutions of 2,4-DTBP at predefined concentrations (0.5, 1, and 2µg/mL) demonstrated recovery rates between 98.44% and 98.97%, with %RSDs less than 2%, indicating high accuracy. Inter-day and intra-day precision studies for levels of (0.2, 0.4, 0.8 and 1.6µg/mL) showed %RSDs below 2%. Robustness tests, involving slight changes in column temperature (±2°C) and flow rate (±0.1mL), resulted in %RSDs between 0.05% and 1.03%. The LOD and LOQ were determined to be 0.06µg/mL and 0.19µg/mL, respectively. Quantification results for wastewater samples from SP1, SP2, and SP3 were 3.35µg/mL, 1.17µg/mL, and 1.23µg/mL, respectively, demonstrating the method's optimization and feasibility for analyzing low concentrations of 2,4-DTBP in these samples. The results of all the parameters for this method were found to be in compliance with the acceptance criteria according to the guidelines of the International Council for Harmonisation (ICH).