Ultra-fast liquid chromatographic determination of atomoxetine, duloxetine, paroxetine, fluoxetine and sertraline in tap water, urine, and pharmaceutical formulations using 7,7,8,8-tetracyanoquinodimethane as a derivatization reagent

The widespread consumption of pharmaceuticals, including both human and veterinary drugs, has resulted in the accumulation of these substances in aquatic ecosystems, presenting significant ecological threats. Psychoactive drugs, particularly antidepressants, raise particular concern due to their direct effects on brain chemistry. The growing contamination of global water systems, especially in urban environments, underscores the increasing presence of these substances in nature. A novel analytical method using UFLC-UV was developed and validated for the quantification of Atomoxetine (ATM), Duloxetine (DLX), Paroxetine (PRX), Fluoxetine (FLX) and Sertraline (SRT) in tap water, urine, and pharmaceutical samples. This technique relies on creating a purple chromogen through a displacement reaction with TCNQ in acetonitrile, with heating at 80 °C for 20 minutes. The processed sample was then injected into a C18 column. Separation was performed using acetonitrile–water (85:15) as mobile phase at 1.0 mL/min flow rate. Detection was carried out at 567 nm. The method showed linearity in the range of 10–100 ng/mL for all compounds. The validated procedure was successfully implemented to identify these antidepressants in tap water, urine, and pharmaceutical formulations. Recovery values were found between 95.41 to 100.85%. The LOD values ranged from 1.02 to 1.98 ng/mL in all of the sample matrices.