Análisis de fármacos en aguas residuales de tres hospitales de la ciudad de Puebla, México.

Artículo en revista indizadaMediante sus efluentes, los hospitales contribuyen a la ocurrencia de microcontaminantes emergentes como los fármacos, en el agua. Este trabajo cuantificó la presencia de nueve fármacos en las aguas residuales de tres hospitales privados de México con 66, 92 y 120 camas, respectivamente. Las muestras se caracterizaron fisicoquímicamente y, empleando cromatografía líquida de alta resolución acoplada a espectrometría de masas (UPLC-MS/MS), se reportaron las siguientes concentraciones máximas promedio: paracetamol (38740.11±33832.15 ng/L), naproxeno (6321.42±11074.86 ng/L), ketorolaco (1429.80±237.94 ng/L), ibuprofeno (249.46±143.68 ng/L), ranitidina (149.60±303.70 ng/L), hidrocortisona (96.72±57.21 ng/L), dexametasona (33.02±41.23 ng/L), esomeprazol (22.85±24.12 ng/L) y omeprazol (22.50±23.97 ng/L). En aguas tratadas se detectó una reducción del 67 al 100% en los niveles de hidrocortisona, naproxeno, paracetamol y ranitidina. Los resultados obtenidos informan la presencia de fármacos que no habían sido reportados previamente en efluentes hospitalarios mexicanos y demuestran el impacto de las plantas de tratamiento, contribuyendo a la evidencia existente para impulsar acciones de regulación, innovación tecnológica y monitoreo.Los autores agradecen al Consejo Nacional de Ciencia y Tecnología (CONACYT) de México por el apoyo para la realización de esta investigación dentro del marco del Proyecto No. PN 2016 - 3620. Esta investigación también fue parcialmente apoyada por la Vicerrectoría Académica de la UDLAP (proyecto de investigación interno 2019)

Electrochemical behaviour of dopamine at covalent modified glassy carbon electrode with l-cysteine: preliminary results

The surface of glassy carbon (GC) electrode has been modified by oxidation of L-cysteine. The covalent modified GC electrode with L-Cysteine has been studied, according the supporting electrolyte used. Favourable interactions between the L-cysteine film and DA enhance the current response compared to that at the Nafion GC and bare GC electrodes, achieving better performances than those other electrodes. This behaviour was as result of the adsorption of the cysteine layer film, compact and uniform formation; depending on L-cysteine solution (phosphate buffer or chloridric acid supporting electrolyte) used for modifying GC surface. In cyclic voltammetric measurements, modified electrodes can successfully separate the oxidation/reduction DA peaks in different buffer solutions, but an evident dependence in the response was obtained as function of pH and modified electrode. The modified electrode prepared with L-cysteine/HCl solution was used to obtain the calibration curve and it exhibited a stable and sensitive response to DA. The results are described and discussed in the light of the existing literature

Plasmonic Spherical Nanoparticles Coupled with Titania Nanotube Arrays Prepared by Anodization as Substrates for Surface-Enhanced Raman Spectroscopy Applications: A Review

As surface-enhanced Raman spectroscopy (SERS) continues developing to be a powerful analytical tool for several probes, four important aspects to make it more accessible have to be addressed: low-cost, reproducibility, high sensibility, and recyclability. Titanium dioxide nanotubes (TiO2 NTs) prepared by anodization have attracted interest in this field because they can be used as safe solid supports to deposit metal nanoparticles to build SERS substrate nanoplatforms that meet these four desired aspects. TiO2 NTs can be easily prepared and, by varying different synthesis parameters, their dimensions and specific features of their morphology can be tuned allowing them to support metal nanoparticles of different sizes that can achieve a regular dispersion on their surface promoting high enhancement factors (EF) and reproducibility. Besides, the TiO2 photocatalytic properties enable the substrate’s self-cleaning property for recyclability. In this review, we discuss the different methodological strategies that have been tested to achieve a high performance of the SERS substrates based on TiO2 NTs as solid support for the three main noble metal nanoparticles mainly studied for this purpose: Ag, Au, and Pt