Ibuprofen (IBU), paracetamol (PARA), and diclofenac (DIC) are three of the most used non-opioid analgesics and are most frequently detected in the environment. Some methods to analyze these compounds in water have been previously reported, but they have limitations such as long analysis time, high reagent consumption, and lack of sensitivity. An electrospray ionization high-performance liquid chromatography–mass spectrometry (ESI-HPLC-MS/MS)-based method was developed for the determination of these analgesics, applying 3D printing to improve the extraction process. The method was validated and applied to quantify the target pharmaceuticals using commercial tablets. For PARA and DIC, a gradient elution with 0.1% formic acid in water (A) and 0.1% formic acid in acetonitrile (B) was employed. For the analysis of IBU, an isocratic elution with 10 mM acetate in water (A) and acetonitrile (B) was used. ESI-MS/MS spectra were obtained in positive polarity to identify DIC and PARA, while negative polarity was used for IBU. LOD were 40.91, 3.64, and 1.96, and the LOQ were 136.36, 12.15, and 6.52 ng/L for IBU, PARA, and DIC, respectively. R2 was >0.99 and RSD < 10% in all cases. The 3D-printed extraction device can be used for up to 10 cycles. This method demonstrated a remarkable performance compared to previous studies, mainly in terms of precision (RSD = 0.6–4.16%), mobile phase consumption (4 mL), and analysis time (<7 min), and was applied in the analysis of surface water samples.
Rodríguez-Saldaña et al. (2026) studied this question.