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A simple and sensitive magnetic solid phase extraction (MSPE) method was developed for the separation-preconcentration and speciation of Cr in water samples. The system is based on the adsorption of Cr (VI)-ammonium pyrrolidinedithiocarbamate (APDC) complex on the activated charcoal@MoSe2@Fe3O4 composite. Total chromium has also been determined after the conversion of Cr (III) to Cr (VI) by oxidation with KMnO4. Cr (III) was determined as the difference between the total content of the Cr and Cr (VI). For quantitative recoveries, the effects of solution pH, adsorbent amount, volume of the sample, ligand volume, eluent type, and volume and effect of foreign ions were investigated. The limit of detection and limit of quantification for Cr was 0.36 ng mL−1 and 1.19 ng mL−1, respectively. The procedure was applied for the determination and speciation of chromium in water samples. [ABSTRACT FROM AUTHOR]

A sophisticated electrochemical sensor is presented employing a glassy carbon electrode (GCE) modified with a novel composite of synthesized graphitic carbon nitride (g-C3N4) and CoNiO2 bimetallic oxide nanoparticles (g-C3N4/CoNiO2). The sensor's electrocatalytic capabilities for Sunitinib (SUNI) oxidation were demonstrated exceptional performance with a calculated detection limit (LOD) of 52.0 nM. The successful synthesis and integrity of the composite were confirmed through meticulous characterization using various techniques. FT-IR analysis affirmed the successful synthesis of g-C3N4/CoNiO2 by providing insights into its molecular structure. XRD, FE-SEM, SEM–EDX, and BET analyses collectively validated the material's structural integrity, surface morphology, and electrocatalytic performance. Optimization of key analytical parameters, such as loading volume, concentration, electrolyte solution type, and pH, enhanced the electrocatalytic sensing capabilities of g-C3N4/CoNiO2. The synergistic interaction between g-C3N4 and CoNiO2 bimetallic oxide nanoparticles executed the sensor highly effective in the electrical oxidation of SUNI. Across a concentration range of 0.1–83.8 µM SUNI, the anodic peak current exhibited a linear increase with good precision. Application of the newly developed g-C3N4/CoNiO2 system to detect SUNI in a variety of samples, including urine, human serum, and capsule dosage forms, obtained satisfactory recoveries ranging from 97.1 to 103.0%. This methodology offers a novel approach to underscore the potential of the developed sensor for applications in biological and pharmaceutical monitoring. [ABSTRACT FROM AUTHOR]

Detection and removal of trace amounts of toxic organic and inorganic pollutants in water and wastewater is important for the entire ecosystem. The development of new materials for the determination and removal of contaminants is constantly necessary. Layer double- hydroxides (LDHs) form a broad class of nanomaterials that represent anionic clay composite material used in research and development applications to protect the environment from pollutants. LDH structures functionalized with carbon-based materials are promising adsorbents in the extraction of organic and inorganic pollutants through adsorption and ion exchange mechanisms due to their increased versatility. This review describes recent studies on carbon-containing structure-based LDH composites used in the determination and removal of organic and inorganic pollutants in water and wastewater. Thus, it will lead to the realization of new studies for the determination and removal of different pollutants in other matrices besides water samples of LDHs. [ABSTRACT FROM AUTHOR]

A microextraction method has been developed for the determination of rhodamine B (Rh-B) in water and cosmetics by separation and preconcentration with liquid microextraction based upon a switchable hydrophilic solvent and determination by spectrophotometry. The analyte was extracted into the triethylamine (TEA) phase using sodium hydroxide (NaOH) to convert protonated triethylamine carbonate (P-TEA-C) to triethylamine. Various analytical parameters such as the pH of the sample solution, extraction solvent volume, and sample volumes affecting the quantitative recovery values of rhodamine B were optimized. The limit of detection (LOD) and limit of quantification (LOQ) were 2.96 and 9.88 ng/mL, respectively. The developed method was successfully applied to the determination of rhodamine B and satisfactory recovery values were obtained. The developed approach is fairly fast and an environmentally friendly alternative for the separation and preconcentration of rhodamine B water and cosmetic samples. [ABSTRACT FROM AUTHOR]

An efficient and simple deep eutectic solvent (DES)-based liquid phase microextraction method has been used for chromotrope 2R dyestuff at trace levels prior to its UV-Vis spectropthometric determination. In this aspect, DES was prepared by decanoic acid and tetra-n-butylammonium bromide component used as 1:3 molar ratios. The developed separation-preconcentration method was optimised various analytical parameters such as pH, sample volume, eluent sample volume, volume of DES, sample volume of tetrahydrofuran (THF) and matrix effect etc. on the recovery of chromotrope 2R dyestuff were investigated. Quantitative recovery data for chromotrope 2R were found at pH 3.0. The detection limits of the chromotrope 2R were found to be as 5.4 µg L−1. The accuracy of the developed method was successfully applied by the determination of the addition-recovery studies in the water sample, detergent and food samples with satisfactory results. The proposed method was applied to natural water samples for the determination of chromotrope 2R with satisfactory results. [ABSTRACT FROM AUTHOR]

A solid-phase extraction method for separation-preconcentration of copper as 1-(2-pyridylazo)-2-naphthol (PAN) on Coprinus atramentaria has been presented. The copper concentration was determined by micro-sampling flame atomic absorption spectrometry (FAAS). It could be discussed that the developed method has low LOD in addition to high preconcentration factor. By considering the over advantages of recommended method, we can suggest the use of its to preconcentration of Cu(II) by routinly. The various analytical factors affecting the efficiency of extraction were optimised. Copper(II)-PAN chelate was quantitatively recovered at pH 6.0 on Coprinus atramentaria and eluted with 2 M HNO3. The limit of detection, limit of quantification, inter-day and intra-day precision values of copper were 0.7 μg L−1, 2.33 µg L−1, 5.31% and 5.15%, respectively. The pre-concentration factor was 70. The method was confirmed by applying the method to certified reference materials and addition–recovery tests prior to application to the determination of copper ions in various samples recovery results. The solid-phase extraction with FAAS is a successful method for the determination of copper in different samples. [ABSTRACT FROM AUTHOR]

A new magnetic core-shell multiwalled carbon nanotube@nanodiamond nanocomposite was synthesized, characterized and used as magnetic solid-phase extraction material. The usability of material was checked on the separation and pre-concentration of quercetin in tea samples by magnetic solid-phase extraction and high-performance liquid chromatography with diode array detector system. There was a linear relationship between chromatographic area and concentration of quercetin in the range of 5.0–600 ng mL−1. The limit of detection and quantification limits were 1.46 and 4.91 ng mL−1, respectively. The developed method has been applied to determine quercetin at trace levels in tea samples. [ABSTRACT FROM AUTHOR]

In this study, preconcentration and separation of Cu(II) and Pb(II) ions by using Fe3O4@SiO2@Bacillus pumilis before their determinations by flame atomic absorption spectrometry (FAAS) were investigated. The thermophilic Bacillus pumilis were isolated from Meyremderesi spring, Şırnak, Turkey. Effects of important parameters such as pH, adsorbent amount, eluent type, concentration and volume of eluent and sample volume on magnetic solid phase extraction (MSPE) were examined in details. The preconcentration factors for Cu(II) and Pb(II) ions were calculated as 30 and 40, respectively. The accuracy of the proposed extraction procedure was validated analysing certificated reference materials and addition – recovery tests. The concentration of copper and lead were determined in water samples from Turkey by Flame AAS after application developed preconcentration-separation method. [ABSTRACT FROM AUTHOR]