A innovative switchable polarity solvent,based on 1,8‐diazabicyclo‐[5.4.0]‐ undec‐7‐ene and decanol was prepared for enrichment of aluminum in biological sample prior to analysis by flame atomic absorption spectrometry

A novel switchable solvent (SS) extraction methodology has been used for the enrichment of aluminium (Al) in acid‐digested blood samples of patients with neurological disorders before proceeding to flame atomic absorption spectrometry. 1,8‐Diazabicyclo[5.4.0]undec‐7‐ene and decanol in combination made a SS which reversibly changes from hydrophobic (nonpolar) to hydrophilic (polar) according to switch‐on and switch‐off phenomena in aqueous medium by exposure to anti‐solvent trigger (CO₂). The SS polar micro‐emulsion was switched on by bubbling CO₂, and switched off by heating from 40 to 70°C with exposure to N₂ gas. The changes obtained in the structure and physical properties of the SS due to switching from lower polarity to higher polarity were investigated using Fourier transform infrared spectroscopic analysis. The SS was effectively analysed as an extractive medium for hydrophobic chelate of Al with 3,5,7,2,4‐pentahydroxyflavone (morin) and extracted in SS. Then hydrophobic enriched Al‐morin‐SS was treated with 1.0 M HNO₃ and CO₂ purging at various time intervals, switch to a miscible polar hydrophilic monophase state. The SS was easily recycled up to six times for further enrichment process. For the developed method, various parameters were optimized such as pH, volume of chelating reagent, CO₂ purging time and pressure, and rate of heating. Under favourable conditions, enhancement factor and limit of detection were observed as 25 and 0.47 μg l^?1, respectively, for 10 ml of samples/standards solution. The accuracy of the developed method was determined using certified reference material (SRM 3101a), with a standard addition procedure. The method was used for the pre‐concentration of Al in blood samples of patients with neurological disorders.     

Phase transition,electronic and optical properties of III-Sb compounds under pressure

III-V semiconductors are the backbone of optoelectronic industry. Here, we have performed first principle calculations to investigate the structural, electronic and optical properties of III-Sb (III = B, Al, Ga, Sb) compounds under the effect of pressure. The structural phase transition from zincblende to rocksalt phases is determined by the common tangent of the two E–V curves. The obtained results are in good agreement with the available literature. Compounds make electronic transition from semiconductors to metals under pressure. The calculated band structure in zincblende structure was compared with experimental and theoretical findings. Optical properties including real and imaginary parts of the complex dielectric function, frequency-dependent reflectivity and optical conductivity are explained to characterize the optical nature of these compounds in both phases.     

Development of a new green non-dispersive ionic liquid microextraction method in a narrow glass column for determination of cadmium prior to couple with graphite furnace atomic absorption spectrometry

Easy and innovative non-dispersive ionic liquid based microextraction (NDILME) has been developed for preconcentration of trace level of cadmium (Cd) in aqueous real surface water samples prior to couple with graphite furnace atomic absorption spectrometry (GFAAS). A 200 cm long narrow glass column containing aqueous solution of standard/sample was used to increase phase transfer ratio by providing more contact area between two medium (aqueous and extractive), which drastically improve the recoveries of labile hydrophobic chelate of Cd ammonium pyrrolidinedithiocarbamate (APDC), into ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate [C₄mim][PF₆]. Different aspect of the desire method have been investigated and optimized. Under the optimized key experimental variables, limit of detection (LOD) and enhancement factor (EF) were achieved to be 0.5 ng L⁻¹ and 150, respectively. Reliability of the model method was checked by relative standard deviation (%RSD), which was found to be < 5%. Validity and accuracy of the developed method was checked by analysis of certified reference water samples (SLRS-4 Riverine water) using standard addition method.     

Nanoparticles decorated with a Schiff's base for the microextraction of Cd,Pb, Ni,and Co in environmental samples

In this paper, we report a new liquid–liquid microextraction procedure called “nanoparticles decorated with a Schiff's base for the microextraction of Cd, Pb, Ni, and Co in environmental samples”. The developed procedure was utilized for the extraction of Cd, Pb, Ni, and Co in environmental samples. The Schiff's base was formed by reacting salicylaldehyde with 3‐aminopropyltriethoxysilane‐functionalized iron oxide nanoparticles. Analyte extraction was conducted in a capillary column system loaded with modified nanoparticles and triton X‐114 as dispersion medium. 1‐Butyl‐3‐methylimidazolium hexafluorophosphate was employed as an extraction solvent. Acidified methanol in ultrasonic bath was used as desorption solvent, and elemental determination was carried out with flame atomic absorption spectrometer. Characterization of modified nanoparticles was performed with FTIR spectroscopy and transmission electron microscopy. Solution pH, nanoparticles amount, dispersant concentration, ionic liquid, and temperature were optimized for the extraction. Detection limits obtained for Cd, Pb, Ni, and Co were 0.183, 0.201, 0.241, and 0.192 μg L^?1, respectively, and enhancement factors were 79.1, 86.4, 95.7, and 82.0, respectively. The reproducibility of the developed procedure was in the range of 3.98–5.10%. Validation was checked by applying the developed procedure on certified reference water samples. The microextraction based on nanoparticles decorated with Schiff's base was successfully applied for the extraction of Cd, Pb, Ni, and Co in real environmental water samples.