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In this study, the nanometer-sized ferrous-ferric oxide magnetic nanocomposite (Fe 3 O 4 @MnO 2 @Al 2 O 3 @Au) was successfully synthesized using co-precipitation and sol gel methods The structural, morphological and magnetic properties of the nanocomposite material were characterized by FTIR, BET, XRD, SEM/EDS, Zeta-potential measurements, TEM and VSM. The nanocomposite was applied as a sorbent for preconcentration of As via ultrasound assisted magnetic solid phase extraction (UA-MSPE). The preconcentrated arsenic was quantified using ICP-MS. A 2 5−1 fractional factorial design was used as a tool for optimizing the developed analytical methodologies. Under optimized conditions, the limit of detection and quantification were 8.6 and 28.5 ng L −1 respectively. The intraday (n = 15) and interday (n = 5) precisions of the developed UA-MSPE method expressed in terms of relative standard deviation (%RSD) were 4.1 and 6.2% and the enrichment factor was found to be 95. The extraction efficiency of the current method was greater than 95%. The developed UA-MSPE method was successfully applied in the preconcentration of arsenic in environmental water samples and nanocomposites modified with MnO 2 , Al 2 O 3 , Au and their application for preconcentration of arsenic in river water sample and the concentration ranged from 0.13–0.18 μg L −1 . The Fe 3 O 4 @MnO 2 @Al 2 O 3 @Au nanoadsorbent combined the advantages of magnetic separability and high affinity toward arsenic adsorption. [ABSTRACT FROM AUTHOR]

A micelle-mediated preconcentration method has been developed for determination of Safranine T at trace amounts, which is widely used in textile industry. It can be evaluated as one of the dangereous chemicalsdue to its carcinogenicity and toxic properties. The method is based on the cloud point extraction (CPE) of Safranine T at pH 8.0 in the presence of Triton X-114 as nonionic surfactant. The obtained surfactant-rich phase (SRP) was diluted with ethanol and its absorbance was measured at 532 nm. Experimental parameters affecting preconcentration and determination steps have been optimized. The obtained calibration graph was linear in the range of 4-200 µg L-1 and correlation coefficient was 0.9838. Detection limit was 1.14 µg L-1 and the relative standard deviation for 10 and 100 µg L-1 of Safranine T were 2.7 and 1.8 %, respectively. The method was applied for determination of Safranine T in environmental water samples with satisfactory results. [ABSTRACT FROM AUTHOR]

[Display omitted] In the present study, electrospun zeolitic imidazolate framework-8/poly(lactic acid) nanofibers were successfully synthesized and characterized as a potential nanosorbent for the pipette-tip micro-solid phase extraction of chlorpropham, pirimicarb, carbaryl, and methiocarb carbamate insecticides from environmental water samples. The extraction procedure was followed by gas chromatography/mass spectrometry separation and determination of the target analytes. All the effective parameters of the extraction procedure were optimized through the one variable at-a-time method. Thanks to the very simple extraction procedure as well as the application of electrospun nanofibers with high surface area, the four analytes were efficiently extracted with as lowest extraction times as practicable. Under the optimal conditions, the calibration plots of the analytes were obtained within broad linear dynamic ranges of 0.5 – 150 ng mL−1 for chlorpropham and pirimicarb plus 1.0 – 175 ng mL−1 for carbaryl and methiocarb, respectively. Besides, limits of detection as low as 0.2 and 0.15 ng mL−1 for chlorpropham and pirimicarb, respectively, as well as 0.5 ng mL−1 for carbaryl and methiocarb indicate the favorable sensitivity of the analytical procedure. The applicability of the developed method was evaluated by quantitative determination of the target analytes in four different environmental water samples. Relative recoveries higher than 88.0% shows the acceptable accuracy of the method in the quantitative determination of the four carbamate insecticides. [ABSTRACT FROM AUTHOR]

This study reports a deep eutectic solvent based dispersive liquid-liquid microextraction (DES-DLLME) to extract aromatic amines (4-chloroaniline, 3-nitroaniline, 2-naphtylamine) in environmental water samples before their HPLC-UV determination. The hydrophobic deep eutectic solvent (DES) was prepared by mixing bis(2-ethylhexyl) phosphate (BEHP) as a hydrogen bond acceptor and phenol as a hydrogen bond donor. Affecting factors on the extraction of the aromatic amines were investigated and optimized. Optimum conditions were: DES type: BHHP-Ph ratio: 1 to 2; pH of solution: 8.0; DES volume: 80 µL, salt amount: 10% (w/v). Under optimum conditions, the developed method showed a wide linear range of 0.2–200 µg L−1 (R2 ≥ 0.99) with satisfactory recoveries (≥90.0%). The limit of detections (LODs) and limit of quantifications (LOQs) were in the range of 0.07–0.17 µg L−1 and 0.2–0.5 µg L−1, respectively. The enrichment factors were 170, 180 and 190 for 4-chloroaninile, 3-nitroaniline, 2-naphtylamine, respectively. Based on obtained results, the proposed method is straightforward, efficient, sensitive, and eco-friendly for the extracting and determining of the aromatic amines in environmental water samples. [ABSTRACT FROM AUTHOR]

A new solid phase extractor named silica gel immobilized indapamide (4-chloro-N-(2-methyl-2,3-dihydroindol-1-yl)-3-sulfamoylbenzamide) (SG-INDP) was synthesized by microwave free-solvent technique as a new environmentally friendly modification method. This new phase was investigated for removal of copper ions from aqueous media. It was characterized by the FT-IR, scan electron microscope and X-ray diffraction analyses. The effects of sample pH, time of equilibrium, sorbent weight, copper ions concentrations and interfering ions were studied and optimized using batch technique at room temperature. The maximum percentage of extraction of Cu(II) (99.90 ± 0.1%) using SG-INDP was achieved. The fast adsorption equilibrium could be reached within 20 min and the kinetic data were fitted well by a pseudo-second-order equation ( r 2 = 0.999). Results of sorption isotherms of the sorbent were better fitted with the Langmuir ( r 2 = 0.994) and Freundlich ( r 2 = 0.985) models. The new synthesized solid phase extractor was applied for removal of Cu(II) from natural water samples. [ABSTRACT FROM AUTHOR]

An ionic liquid aqueous two-phase solvent subla-tion (IL-ATSS) of l-hexyl-3-methylimidazolium Bromide ([C6min]Br)/Tri-potassium Citrate (K3C6H5O7) coupled with high performance liquid chromatography (HPLC) method was developed for the separation and determination of sulfamethoxazole (SMX) in water samples. The optimal conditions were investigated and discussed. The real water samples containing SMX were analyzed, and the results were satisfying. The limit of detection (LOD) was 0.8 ng mL-1, and the limit of quantification (LOQ) was 2.7 ng mL-1. In addition, the enrichment factor (22.7) of IL-ATSS is higher than ionic liquids aqueous two-phase extraction (9.6). This novel process is suited to separation and enrichment a massive dose and low content of substances in the environ-ment. [ABSTRACT FROM AUTHOR]

Abstract: A method based on cloud point extraction(CPE) was developed for the determination of 2,4-dichlorophenol in environmental water samples using high-performance liquid chromatography separation and ultraviolet (HPLC-UV) detection. The non-ionic surfactant Triton X-100 was chosen as extraction solvent. The parameters and affecting factors of extraction efficiency, such as concentration of Triton X-100 and sodium chloride, acidity of solution, equilibrium temperature, equilibrium time and centrifugation time were evaluated and optimized. Under the optimum conditions: 0.9% (w/v) Triton X-100, 0.2mol/L sodium chloride and 0.4% (v/v) hydrochloride, heat-assisted at 80°C for 60min, the extraction efficiencies was more than 95%. The results show that the linear dynamic ranges of detection is 0.005∼0.5mg/L for 2,4-dihlorophenol with the correlation coefficient of 0.9998, and the limit of detection is 2.0×10-2μg/L (3σ) with relative standard deviation (RSD) of 3.51% (n = 9). The enhancement factor can achieve 33 for the determination of 2,4-dichlorophenol in environmental water samples. The recoveries range from 94.4% to 104.0% for three environmental water samples. The proposed method is simple, rapid, sensitive, accurate and friendly to environment. It is suitable to the determination of 2,4-dichlorophenol in environmental water samples. [Copyright &y& Elsevier]

The ubiquitous occurrence of steroid estrogens (SEs) in the aquatic environment has raised global concern for their potential environmental impacts. This paper extensively compiled and reviewed the available occurrence data of SEs, namely estrone (E1), 17α-estradiol (17α-E2), 17β-estradiol (17β-E2), estriol (E3), and 17α-ethinyl estradiol (EE2), based on 145 published articles in different regions all over the world including 51 countries and regions during January 2015–March 2020. The data regarding SEs concentrations and estimated 17β-estradiol equivalency (EEQ) values are then compared and analyzed in different environmental matrices, including natural water body, drinking and tap water, and wastewater treatment plants (WWTPs) effluent. The detection frequencies of E1, 17β-E2, and E3 between the ranges of 53%–83% in natural water and WWTPs effluent, and the concentration of SEs varied considerably in different countries and regions. The applicability for EEQ estimation via multiplying relative effect potency (REP i) by chemical analytical data, as well as correlation between EEQ bio and EEQ cal was also discussed. The risk quotient (RQ) values were on the descending order of EE2 > 17β-E2 > E1 > 17α-E2 > E3 in the great majority of investigations. Furthermore, E1, 17β-E2, and EE2 exhibited high or medium risks in water environmental samples via optimized risk quotient (RQ f) approach at the continental-scale. This overview provides the latest insights on the global occurrence and ecological impacts of SEs and may act as a supportive tool for future SEs investigation and monitoring. Image 1 • Five-year period worldwide occurrence status of steroid estrogens is summarized. • The utilization of 17β-estradiol relative effect potency (REP i) is discussed. • Estrogenic activity and environmental risks of steroid estrogens are assessed. • Control strategies are further required to efficiently eliminate steroid estrogens. [ABSTRACT FROM AUTHOR]