Trimethoprim Hydrochloride

The study details the synthesis of quercetin-capped Au-Ag bimetallic nanoparticles (Qct-AuAg BMNps) in an aqueous environment.UV visible spectra showed absorbance peak of gold and bimetallic nanoparticles at 524 nm and 403 nm, resp.The SEM anal. of Qct-AuAg BMNps showed an average particle size of 67.5 nm with good uniformity (PdI: 0.386).FTIR confirmed the presence of resp. functional groups in Qct-AuAg BMNps.The Qct-AuAg BMNps were used as a colorimetric sensor for detecting calcium dobesilate monohydrate (CDM) in aqueous solutions, showing a linear spectrophotometric relationship with CDM concentration ranging from 0.000001 mM to 10 mM (R² = 0.9984).The detection and quantification limits were 1.66 x 10^-6 and 2.71 x 10^-5 mM, resp.The binding constant (K_a) was 9.8 x 10⁴ M^-1, with a 1:1 stoichiometry confirmed by Job's plot.The Qct-AuAg BMNps were successfully used to detect CDM in tap water and serum samples.The synthesis process was optimized using Box Behnken Design, with the optimal conditions found at 50°C, 2 mM quercetin, and a 5:1 silver-to-gold ratio.Therefore, the synthesized quercetin capped gold silver bimetallic nanoparticles were proved effective for the detection of CDM in liquid samples.

The aim of this study was to determine the occurrence and perform the environmental risk assessment (ERA) for emerging contaminants, primarily pharmaceuticals and personal care products (PPCPs), in the groundwater near a closed municipal landfill, on the example of a site in Tychy (southern Poland).Groundwater from a shallow aquifer was sampled in two seasons from eight piezometers located upstream, downstream, and on top of the landfill.The anal. covered 128 PPCPs.Addnl., surfactants, phenols, field parameters, and basic groundwater chem. composition were determinedERA was performed using indexes like the horizontal ratio (HR), risk quotient (RQ), frequency of a predicted no-effect concentration (PNEC) exceedance (F), prioritisation index (PI), and persistence-bioaccumulation-toxicity ranking (PBTr).The number of detected PPCPs in the groundwater reached up to 54, with total PPCP concentrations ranging from 492 to 3,230,036 ng/L.The study also revealed the presence of phenols (up to 62 mg/L) and surface active agents, particularly anionic surfactants (up to 77.7 mg/L).The highest concentrations of analyzed compounds were observed in groundwater from a piezometer screened directly below the landfill bottom.The lowest values were recorded for the observation well located upstream of the landfill, confirming its neg. impact and the release of PPCPs into the aquifer.The influence of the landfill was also reflected by low HR values (below 1) and high values of the site-specific risk quotient (above 1).Based on PI results, ibuprofen, bisphenol A, propyphenazone, and sulfamerazine were considered the compounds of highest risk.The same substances were among compounds with the highest PBTr values.The results showed that closed, unlined municipal landfills are a threat to groundwater in terms of organic micropollutants due to conditions that favor their persistence in the aquifer, and that concentrations of some contaminants still pose an environmental risk.