Development of magnetic nanomaterials has greatly promoted the innovation of in-tube solid-phase microextraction. This review article gives an insight into recent advances in the modifications and ...applications of magnetic nanomaterials for in-tube solid-phase microextraction. Also, different magnetic nanomaterials which have recently been utilized as in-tube solid-phase microextraction sorbents are classified. This study shows that magnetic nanomaterials have gained significant attention owing to large specific surface area, selective absorption, and surface modification. Magnetic in-tube solid-phase microextraction has been applied for the analysis of food samples, biological, and environmental. However, for full development of magnetic in-tube SPME, effort is still needed to overcome limitations, such as mechanical stability, selectivity and low extraction efficiency. To achieve these objectives, research on magnetic in-tube SPME is mainly focused in the preparation of new extractive phases.
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•Four groups of materials, used as coatings for magnetic in-tube SPME, were reviewed.•Silica and layered double hydroxides as coatings in magnetic in-tube SPME were investigated.•The roles of variable magnetic field in magnetic in-tube SPME are described.•Magnetic in-tube SPME techniques as well-known sample preparation methods were described.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This study introduces an electrochemical sensor designed for the determination of ascorbic acid (AA), dopamine (DA), and acetaminophen (AC). The sensor was crafted through a single ...electropolymerization step in a solution containing pyrrole and modified gold nanoparticles. Characterization of the resulting polypyrrole composite was conducted using diverse techniques, including scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, UV–vis spectroscopy, dynamic light scattering, electrochemical impedance spectroscopy, and cyclic voltammetry. Differential pulse voltammetry was employed to record peak currents for the oxidation of the analytes. The sensor exhibits a linear response within the concentration ranges of 20–1000 μM for AA, 0.1–8.0 μM for DA and 4.0–150 μM for AC with detection limits (3
σ
) of 8.8 μM for AA, 79 nM for DA and 0.9 μM for AC, respectively. The efficacy of the developed sensor was validated through the electrochemical determination of these analytes in human serum, ampoules, and tablets, demonstrating its practical applicability in real samples.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The aggregation behavior was investigated in mixtures of sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB) (anionic-rich catanionic) solutions. The study was conducted in ...solutions of water–ethylene glycol (EG) by means of surface tension, conductometry, cyclic voltammetry, zeta potential measurements, transmission electron microscopy (TEM) and dynamic light scattering (DLS) techniques. The degree of counterion dissociation (
α
), critical micelle concentration, aggregation numbers, interfacial properties, interparticle interaction parameters, and morphology of aggregates were determined. Based on regular solution theory, the cosolvent effects between SDS and CTAB as surfactants were also analyzed for both mixed monolayers at mixed micelles (
β
M
) and the air/liquid interface (
β
σ
). It was shown that the formation of large aggregates occurred in the presence of an excess of anionic surfactant. A phase transition from cylindrical micelles to spherical micelles in the anionic-rich regime was observed with an increase in the EG volume fraction. The inter particle interactions were assessed in terms of cosolvent effects on the micellar surface charge density and the cylindrical-to-spherical morphology change. Zeta potential and size of the aggregates were determined using dynamic light scattering and confirmed the models suggested for the processes taking place in each system.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Tumor markers are highly sensitive and play an important role in the early diagnosis of cancer. We developed an electrochemical sandwich-type immunosensor that detects human epidermal growth factor ...receptor 2 (HER2). Magnetic framework (Fe
3
O
4
@ TMU-24) and AuNPs (Fe
3
O
4
@ TMU-24 -AuNPs) are utilized in this sensing platform. In addition to their high specific surface area and excellent biocompatibility, Fe
3
O
4
@ TMU-24-AuNPs nanocomposites exhibited excellent electrocatalytic properties. The primary antibody of HER2 (Ab
1
) was immobilized on the surface of the Fe
3
O
4
@ TMU-24-AuNPs. In this sensing method, palatine doped to CdTe QDs (Pt: CdTe QDs) is utilized as a novel labeling signal biomolecule (secondary antibodies). Pt: CdTe QDs own good biocompatibility and excellent catalytic performance. The amperometric technique was used to achieve the quantitative determination of HER2 by using a sandwich-type electrochemical immunosensor. Under the optimum conditions, the dependency of the current signal and HER2 concentration showed a linear region from 1 pg ml
−1
–100 ng ml
−1
with 0.175 pg ml
−1
as the limit of detection. This biosensing device also showed long stability and good reproducibility, which can be used for the quantitative assay of HER2.
•Speciation of chromium in different water samples.•Chelating of Cr species with APDC and quantification using HPLC.•Application of dual electromembrane extraction system.•Simultaneous extraction of ...anionic and cationic species of Cr.•Quantification of Cr(VI) and Cr(III) in tap, mineral and river water samples.
This study proposes the dual electromembrane extraction followed by high performance liquid chromatography for selective separation-preconcentration of Cr(VI) and Cr(III) in different environmental samples. The method was based on the electrokinetic migration of chromium species toward the electrodes with opposite charge into the two different hollow fibers. The extractant was then complexed with ammonium pyrrolidinedithiocarbamate for HPLC analysis. The effects of analytical parameters including pH, type of organic solvent, sample volume, stirring rate, time of extraction and applied voltage were investigated. The results showed that Cr(III) and Cr(VI) could be simultaneously extracted into the two different hollow fibers. Under optimized conditions, the analytes were quantified by HPLC instrument, with acceptable linearity ranging from 20 to 500μgL−1 (R2 values≥0.9979), and repeatability (RSD) ranging between 9.8% and 13.7% (n=5). Also, preconcentration factors of 21.8–33 that corresponded to recoveries ranging from 31.1% to 47.2% were achieved for Cr(III) and Cr(VI), respectively. The estimated detection limits (S/N ratio of 3:1) were less than 5.4μgL−1. Finally, the proposed method was successfully applied to determine Cr(III) and Cr(VI) species in some real water samples.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In this work, for the first time, a rapid, simple and sensitive microextraction procedure is demonstrated for the matrix separation, preconcentration and determination of inorganic selenium species ...in water samples using an electrochemically controlled in-tube solid phase microextraction (EC-in-tube SPME) followed by hydride generation atomic absorption spectrometry (HG-AAS). In this approach, in which EC-in-tube SPME and HG-AAS system were combined, the total analysis time, was decreased and the accuracy, repeatability and sensitivity were increased. In addition, to increases extraction efficiency, a novel nanostructured composite coating consisting of polypyrrole (PPy) doped with ethyleneglycol dimethacrylate (EGDMA) was prepared on the inner surface of a stainless-steel tube by a facile electrodeposition method. To evaluate the offered setup and the new PPy-EGDMA coating, it was used to extract inorganic selenium species in water samples. Extraction of inorganic selenium species was carried out by applying a positive potential through the inner surface of coated in-tube under flow conditions. Under the optimized conditions, selenium was detected in amounts as small as 4.0 parts per trillion. The method showed good linearity in the range of 0.012–200 ng mL−1, with coefficients of determination better than 0.9996. The intra- and inter-assay precisions (RSD%, n = 5) were in the range of 2.0–2.5% and 2.7–3.2%, respectively. The validated method was successfully applied for the analysis of inorganic selenium species in some water samples and satisfactory results were obtained.
An electrochemically controlled in-tube solid phase microextraction followed by hydride generation atomic absorption spectrometry was developed for extraction and determination ultra-trace amounts of Se in aqueous solutions. Display omitted
•A nanostructured composite coating consisting of PPy doped with EGDMA was prepared.•The coating was synthesised electrochemically in inner surface of a stainless-steel capillary tube.•It was used to extract Se from water samples followed by hydride generation AAS.•Extraction of selenium was carried out by applying a positive potential into in-tube SPME.•Ultra trace amounts of Se with LOD = 8.0 ppt was detected in aqueous solutions.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
In this study, a simple and rapid extraction method based on the application of polypyrrole‐coated Fe3O4 nanoparticles as a magnetic solid‐phase extraction sorbent was successfully developed for the ...extraction and preconcentration of trace amounts of formaldehyde after derivatization with 2,4‐dinitrophenylhydrazine. The analyses were performed by high‐performance liquid chromatography followed by UV detection. Several variables affecting the extraction efficiency of the formaldehyde, i.e., sample pH, amount of sorbent, salt concentration, extraction time and desorption conditions were investigated and optimized. The best working conditions were as follows: sample pH, 5; amount of sorbent, 40 mg; NaCl concentration, 20% w/v; sample volume, 20 mL; extraction time, 12 min; and 100 μL of methanol for desorption of the formaldehyde within 3 min. Under the optimal conditions, the performance of the proposed method was studied in terms of linear dynamic range (10–500 μg/L), correlation coefficient (R2 ≥ 0.998), precision (RSD% ≤ 5.5) and limit of detection (4 μg/L). Finally, the developed method was successfully applied for extraction and determination of formaldehyde in tap, rain and tomato water samples, and satisfactory results were obtained.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Zn‐based TMU‐24 as a metal–organic framework (MOF), containing amide‐functionalized pores was prepared by a facile and efficient strategy. The obtained TMU‐24 was illustrated to be efficient ...adsorbents for the eosin B removal from an aqueous solution. Due to their large surface area, stability, tunability, and porosity of the TMU‐24, as well as π–π and hydrophobic interactions, hydrogen bonding formation between the dye and the MOF ligands, the fabricated sorbents showed fast adsorption kinetics (9 min) and high adsorption capacity. The effect of important factors such as pH, amount of adsorbent, contact time, and desorption conditions to achieve the optimal removal conditions was investigated. The optimum condition was pH = 6, absorbent dosage 4 mg and contact time 9 min. The adsorption results match with those of the Langmuir model and the pseudo‐second‐order kinetics, suggesting that eosin B was adsorbed to the adsorbent in monolayers due to its chemical affinity. The maximum adsorption capacity of TMU‐24 for the removal of eosin B was 370.37 mg/g. Thermodynamic parameters suggested that the adsorption procedure is spontaneous and exothermic. TMU‐24 exhibited excellent reusability (6 cycles) and had potential in the treatment of dyes polluted wastewater.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Purpose
The purpose of this paper is to document a gap between generation X and Y’s behavior toward decision making for hiring a professional financial planner in context of an emerging country.
...Design/methodology/approach
This research is based on a public survey in Malaysia on the effect of five major contributing factors (namely, awareness, acceptability, affordability, accessibility and assurance) on the decision to hire a professional financial planner. The study further shed light into the difference among the influential factors among generation X and Y.
Findings
Although awareness, acceptability, affordability and assurance have demonstrated significant effect on decision making in general, their impact varies among different age groups. Results of moderation tests on the role of age suggest that for Gen X, the determinant factor is only their acceptability of the financial planning service. However, awareness, affordability, acceptability and assurance are critical factors for Gen Y respondents. In contrast to Gen Y, the Gen X respondents tend to have more awareness toward their needs for financial planning; they have gained enough experience to assess the credibility of the planner and test their assurance; and have higher earnings to afford the financial planners services.
Originality/value
Findings of this study are novel as it provide first hand picture from an emerging market in South-East Asia. Moreover, the study documents generation gap in financial decision making process.
Simultaneous extraction of acidic, basic, and neutral drugs from different biological samples is a considerable and disputable concept in sample preparation strategies. In the present work, a new ...in-tube solid phase microextraction approach named electrochemically controlled double in-tube solid phase microextraction (EC-DIT-SPME) is introduced for simultaneous extraction of acidic, basic, and neutral drugs from different biological matrices. For this purpose, novel nanostructured coatings based on copolymer of polypyrrole and indole-2-carboxylic acid (PPy- co -PIca) as non-overoxidized and overoxidized forms were electrochemically synthesized on the inner surface of stain-less steel tubes. During the extraction procedure, the PPy- co -PIca and overoxidized PPy- co -PIca coated stain-less steel tubes were used as anode and cathode electrodes, respectively. Extraction of basic and acidic drugs were performed on the surface of overoxidized PPy- co -PIca and PPy- co -PIca, which are connected to the negative and positive potentials, respectively. With regard to the fact that neutral drugs can be absorbed in both electrodes, extraction of neutral drugs will be done in both of them. Satisfactory analytical figures of merit including linear dynamic range and limits of detection in the range of 0.15–500 ng mL −1 and 0.05–1.9 ng mL −1 and good extraction recoveries (38.5–78.6%) were obtained. Finally, the proposed method was successfully applied for simultaneous analysis of acidic, basic, and neutral drugs in some biological samples.
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IJS, KILJ, NUK, UL, UM, UPUK
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