Photo-degradation of basic green 1 and basic red 46 dyes in their binary solution by La2O3-Al2O3nanocomposite using first-order derivative spectra and experimental design methodology

In this work, the lanthanum oxide-aluminum oxide (La₂O₃-Al₂O₃) nanocomposite is introduced as an efficient photocatalyst for the photo-degradation of the dyes basic green 1 (BG1) and basic red 46 (BR46) in their binary aqueous solution under the UV light irradiation. The properties of this catalyst are determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Brunauer-Emmett-Teller (BET), and UV-visible spectrophotometry. The first-order derivative spectra are used for the simultaneous analysis of the dyes in their binary solution. The screening investigations indicate that five parameters including the catalyst dosage, concentration of the dyes, irradiation time, and solution pH have significant effects on the photo-degradation of the dyes. The effects of these variables together with their interactions in the photo-degradation of the dyes are studied using the Box-Behnken design (BBD). Under the optimum experimental conditions, obtained via the desirability function, the photo-catalytic activities of La₂O₃-Al₂O₃ and pure Al₂O₃ are also investigated. The results obtained show an enhancement in the photo-catalytic activity when La₂O₃ nanoparticles are loaded on the surface of Al₂O₃ nanoparticles.

Highly effective adsorption of xanthene dyes (rhodamine B and erythrosine B) from aqueous solutions onto lemon citrus peel active carbon: characterization, resolving analysis, optimization and mechanistic studies

Erythrosine B (EB) and rhodamine B (RB) dyes that were selected as model of xanthene dyes for dye adsorption from aqueous solution, were removed effectively.

A Simple Organic Solvent-Free Liquid-Liquid Microextraction Method for the Determination of Potentially Toxic Metals as 2-(5-Bromo-2-pyridylazo)-5-(diethylamino)phenol Complex from Food and Biological Samples

An organic solvent-free method was developed to extract some potentially toxic metals, as complexed with 2-(5-bromo-2-pyridylazo)-5-(diethylamino)phenol, from different real samples prior to their determination by microsampling flame atomic absorption spectrometry. The method, named ionic liquid-based ultrasound-enhanced air-assisted liquid-liquid microextraction (IL-USE-AALLME), is based upon withdrawing and pushing out a mixture of an aqueous sample and an IL (as the extraction solvent) for several times into a conical test tube using a single syringe, placed in an ultrasound bath (as the enhancing mass transfer agent) during the extraction process. Different effective parameters were studied, and at the optimized conditions, limits of detection, linear dynamic ranges, and enrichment factors were ranged from 0.9 to 2.2 μg L(-1), 3.0 to 1023 μg L(-1), and 20 ± 2 to 22 ± 2, respectively. After optimization, the method was successfully applied to determine Pb(2+), Cu(2+), Co(2+), Ni(2+), and Cr(3+) in different biological (hair and nail), vegetable (coriander, parsley, and tarragon), fruit juice (apple, orange, and peach), and water (tap, mineral, and wastewater) samples. The proposed method was compared with two other IL-based and disperser solvent-free methods (i.e., IL-based air-assisted liquid-liquid microextraction and IL-based ultrasound-assisted emulsification microextraction) to demonstrate its performance.

Application of a tandem air-agitated liquid–liquid microextraction technique based on solidification of floating organic droplets as an efficient extraction method for determination of cholesterol-lowering drugs in complicated matrices

To enhance sample clean-up in dispersive liquid–liquid microextraction in complicated matrices, a low-toxicity and sensitive extraction method, tandem air-agitated liquid–liquid microextraction, based on solidification of floating organic droplets is introduced.

Optimized miniaturized air-assisted liquid–liquid microextraction for determination of non-steroidal anti-inflammatory drugs in bio-fluid samples

A miniaturized air-assisted liquid–liquid microextraction method was developed for the simultaneous extraction of amlodipine, atorvastatin, and ibuprofen in some human bio-fluid samples prior to their determination using HPLC.

Ionic-liquid-based hollow-fiber liquid-phase microextraction method combined with hybrid artificial neural network-genetic algorithm for speciation and optimized determination of ferro and ferric in environmental water samples

A novel and environmentally friendly ionic-liquid-based hollow-fiber liquid-phase microextraction method combined with a hybrid artificial neural network (ANN)-genetic algorithm (GA) strategy was developed for ferro and ferric ions speciation as model analytes. Different parameters such as type and volume of extraction solvent, amounts of chelating agent, volume and pH of sample, ionic strength, stirring rate, and extraction time were investigated. Much more effective parameters were firstly examined based on one-variable-at-a-time design, and obtained results were used to construct an independent model for each parameter. The models were then applied to achieve the best and minimum numbers of candidate points as inputs for the ANN process. The maximum extraction efficiencies were achieved after 9 min using 22.0 μL of 1-hexyl-3-methylimidazolium hexafluorophosphate ([C6MIM][PF6]) as the acceptor phase and 10 mL of sample at pH = 7.0 containing 64.0 μg L(-1) of benzohydroxamic acid (BHA) as the complexing agent, after the GA process. Once optimized, analytical performance of the method was studied in terms of linearity (1.3-316 μg L(-1), R (2) = 0.999), accuracy (recovery = 90.1-92.3%), and precision (relative standard deviation (RSD) <3.1). Finally, the method was successfully applied to speciate the iron species in the environmental and wastewater samples.