Adsorption of Congo Red from Aqueous Solution using Doped Strontium Hexaferrite – Zero Valent Iron Nanocomposite: Kinetic, Isotherm, and Thermodynamic Studies

391-397This study has dealt with synthesis of doped strontium hexaferrite / zero-valent iron nanocomposite (SrFe12O19/nZVI) and adsorption of Congo Red (CR) dye by the nanocomposite from aqueous solution was evaluated. The adsorbent was characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) analysis and Scanning Electron Microscopy (SEM). Optimization of experimental conditions such as pH, initial concentration of pollutant, adsorbent weight, contact time, and temperature was done. Maximum removal efficiency was achieved at pH of 8.5, initial concentration of CR=20 μg mL-1, adsorbent weight of 0.12 g with 15 min contact time and 25ºC temperature. Langmuir isotherm with R2=0.9959 seems to have best fit to the CR adsorption results. Also, kinetic studies revealed that adsorption of CR was fitted to the pseudo-second-order model with R2=0.9969. In addition, thermodynamic parameters were evaluated

DIRECT ORTHOGONAL SIGNAL CORRECTION-PARTIAL LEAST SQUARES FOR SIMULTANEOUS SPECTROPHOTOMETRIC DETERMINATION OF SULFAMETHOXAZOLE AND TRIMETHOPRIM IN PHARMACEUTICAL FORMULATION AND SYNTHETIC SAMPLES

International audienc

Use of nanomaterials in the pretreatment of water samples for environmental analysis

The challenge of providing clean drinking water is of enormous relevance in today’s human civilization, being essential for human consumption, but also for agriculture, livestock and several industrial applications. In addition to remediation strategies, the accurate monitoring of pollutants in water sup-plies, which most of the times are present at low concentrations, is a critical challenge. The usual low concentration of target analytes, the presence of in-terferents and the incompatibility of the sample matrix with instrumental techniques and detectors are the main reasons that renders sample preparation a relevant part of environmental monitoring strategies. The discovery and ap-plication of new nanomaterials allowed improvements on the pretreatment of water samples, with benefits in terms of speed, reliability and sensitivity in analysis. In this chapter, the use of nanomaterials in solid-phase extraction (SPE) protocols for water samples pretreatment for environmental monitoring is addressed. The most used nanomaterials, including metallic nanoparticles, metal organic frameworks, molecularly imprinted polymers, carbon-based nanomaterials, silica-based nanoparticles and nanocomposites are described, and their applications and advantages overviewed. Main gaps are identified and new directions on the field are suggested.publishe

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Kinetic and thermodynamic studies of Direct Red 23 removal using zero-valent nanoparticles immobilized on multi walled carbon nanotubes from aqueous solution

383-392In the present study nanoscale zero valent iron (nZVI) has been immobilized on multi-walled carbon nanotubes (MWCNTs) and used to remove Direct Red 23 (DR 23) from aqueous solution. The effect of parameters such as, initial dye concentration, solution pH, adsorbent content, temperature and contact time on the adsorption process have been investigated. The studied adsorbent exhibits high efficiency for dye adsorption and the equilibrium state is achieved in 6 min. For equilibrium studies, three isotherm models, namely Langmuir, Freundlich and Temkin are used. It is found that Langmuir fits very well with experimental data. The kinetic studies suggest the process following pseudo second-order kinetics and involvement of the particle-diffusion mechanism. The value of different thermodynamic parameters, like Gibb’s free energy change, enthalpy change and entropy change of the adsorption process have also been evaluated. The adsorption of DR 23 has been found to be endothermic

Adaptive Neuro-Fuzzy Inference System (ANFIS) Applied for Spectrophotometric Determination of Fluoxetine and Sertraline in Pharmaceutical Formulations and Biological Fluid: Determination of fluoxetine and sertraline in pharmaceutical formulations and biological fluid

The UV-spectrophotometric method of analysis was proposed for simultaneous determination of fluoxetine (FLX) and sertraline (SRT). Considering the strong spectral overlap between UV-Vis spectra of these compounds, a previous separation should be carried out in order to determine them by conventional spectrophotometric techniques. Here, full-spectrum multivariate calibrations adaptive neuro-fuzzy inference system (ANFIS) method is developed.Adaptive neuro-fuzzyinference system (ANFIS) is a neuro fuzzy technique where the fusion is made between the neural network and the fuzzy inference system that is a computational method. The experimental calibration matrix was constructed with 30 samples. The concentration ranges considered were 5-120μg.mL−1fluoxetine and 10-120μg.mL−1sertraline .Absorbance data of the calibration standards were taken between 200-300nm with UV-Vis spectrophotometer. The method was applied to accurately and simultaneously determine the content of pharmaceutical in several synthetic mixtures and real samples. Assaying various synthetic mixtures of the components validated the presented methods. Mean recovery values were found to be 101.26% and 100.24%, respectively for determination of FLX and SRT