Detection of Pharmaceutically Active Compounds in Tap Water Samples by Direct Injection HPLC/MS-MS: A Danger Signal in Deficiency in Residue Management.

To date, there is an increased risk to public health and the environment due to the presence of pharmaceutically active compounds within drinking water supply and distribution networks. Owing to this, a direct injection-HPLC/MS-MS method was developed for the simultaneous determination of 16 active pharmaceutical compounds in tap water samples: amoxicillin, ampicillin, cephalexin, cefotaxime, cefuroxime, ciprofloxacin, clarithromycin, clindamycin, chloramphenicol, cyproterone, erythromycin, flutamide, spironolactone, sulfamethoxazole, tamoxifen, and trimethoprim. Limits of detection (LOD) ranged from 0.2 to 6.0 µg/L while quantification limits (LOQ) from 0.3 to 20 µg/L. Recovery percentages were between 70 and 125%. Total analysis time was short, with all compounds being resolved in less than 2.1 min. Of the 22 tap water samples collected and analyzed, the highest concentrations corresponded to amoxicillin (147 µg/L) and ciprofloxacin (44 µg/L). The findings could set a precedent for establishing safe levels of these compounds and increasing standards for tap water quality in this region.

Iron metal-organic framework supported in a polymeric membrane for solid-phase extraction of anti-inflammatory drugs.

A solid-phase extraction methodology using a MIL-101(Fe)/PVDF membrane was proposed as a useful alternative for the simultaneous determination of naproxen, diclofenac, and ibuprofen, three anti-inflammatory drugs (NSAIDs), in wastewater samples by HPLC-CCD analysis. The MIL-101(Fe) was prepared by a rapid microwave-assisted method and supported in a polymeric PVDF membrane. The prepared material was characterized by X-ray diffraction (XRD), nitrogen adsorption-desorption, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FT-IR). The factors that affect the extraction of the NSAIDs using the MIL-101(Fe)/PVDF membrane as the sample volume, the solution pH and the elution solvent were studied in detail. The selected conditions were 50 mL of sample solution at pH 3 and 5 mL of methanol: acetone (30:70, v v-1) acidified with formic acid at 2% as elution solvent. The analytical method was linear with determination coefficients (r2 ≥ 0.998) in the calibration ranges from 2 to 100 ng mL-1 for naproxen, 20-200 ng mL-1 for diclofenac, and 100-300 ng mL-1 for ibuprofen. The intra and inter-day precision (repeatability and reproducibility, respectively) of the method (RSD%, n = 5) were lower than 4.8% and 7.1%, respectively. The accuracy reported as recovery percentages ranged from 82 to 118%, and the limits of detection were between 1.8 and 32.3 ng mL-1. Moreover, MIL-101(Fe)/PVDF membrane exhibited improved adsorption efficiency compared to that of its analog MIL-101(Cr)/PVDF and the pristine PVDF membranes, obtaining in an easy and rapid (60 min) way a low-cost and low-toxic adsorbent with excellent stability, reusability, mechanic resistance, and simple operation which shows excellent performance.