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Chalcohalides are attractive multifunctional candidates for new material due to their diverse crystal structures and the characteristics that come from the fusing of chalcogenides and halides. Here, we successfully synthesized a new Pb-based chalcohalide with multiple-halogens, namely, Pb3SBrI3, via a hydrothermal reaction using an organic chemical as the source of the sulfur. The Pb3SBrI3 exhibits unique neutral [Pb3SBrI3]∞ layers composed of rich Pb-centered units including PbS3 trigonal pyramids, PbSI4 square pyramids, and PbBr2I4 octahedra that are piled along the a-axis. Notably, the Pb3SBrI3 is the first Pb-based chalcohalide featuring such a 2D structure. In this work, we examined in detail its synthesis, crystal structure, optical properties and theoretical calculation results. [ABSTRACT FROM AUTHOR]

In this study, a novel enhanced dispersive liquid–liquid microextraction method was developed for the determination of four pyrethroid insecticides (deltamethrin, etofenprox, bifenthrin and fenpropathrin) in tea infusions, based on solidified floating organic solvents containing [P4,4,4,12][PF6] generated in situ and a hydrophobic mixture of 1-chlorododecane and 1-dodecanol. Both the hydrophobic mixture and [P4,4,4,12][PF6] were used as extractants in this method. Several key factors, such as the solvent mixture dosage, the molar ratio of [P4,4,4,12]Br to KPF6, the reaction temperature and the added salt concentration, that affected the recovery were optimized. According to the results of spiked recovery experiments under optimized conditions, the recoveries of all four pyrethroid pesticides ranged from 81.2% to 103.7%, with relative standard deviation (RSD) values ranging from 2.2% to 5.1%. The limit of detection (LOD) values for deltamethrin, etofenprox, bifenthrin and fenpropathrin were 0.39 μg L−1, 0.47 μg L−1, 0.42 μg L−1 and 0.68 μg L−1, respectively. This method fully utilizes the advantageous characteristics of ionic liquids (ILs) and adds the extractant mixture simultaneously to the IL, making the whole experimental process environmentally friendly, efficient, simple and fast. Overall, this is an effective method for the detection of pyrethroid pesticide residues in tea infusions. [ABSTRACT FROM AUTHOR]

A pretreatment method using hyperbranched polyester (HBPE) composite as sorbent based on dispersive micro-solid-phase (d-μ-SPE) extraction preceding high-performance liquid chromatography analysis was developed for the determination of benzoylurea insecticides (BUs) in water samples. Parameters that may influence the extraction efficiency, such as the diameter and the amount of the sorbent, extraction and desorption time and the pH value of the solution, were investigated and optimized using batch and column procedures. Under optimized conditions, good linearity was obtained for all of the tested compounds, with r values of at least 0.9924. The linearity of the method was determined in the range of 1–25 000 μg L−1. The limits of detection (LODs) ranged from 0.024 to 0.068 μg L−1. The recoveries of the four benzoylurea insecticides in water samples increased from 85.50–96.12%. The results confirmed the possibility of using hyperbranched polyester in the determination of relatively hydrophobic trace pesticides residues. Finally, the proposed method was applied to the determination of BUs in water samples with satisfactory results. [ABSTRACT FROM AUTHOR]

In the present study, a convenient, low-cost, sensitive and environmentally friendly method for the determination of four benzoylurea insecticides (BUs) in water and tea beverage samples was developed. The alkalized luffa sponge fibers (AL) were modified by the ionic liquid 1-hexadecyl-3-methylimidazolium bromide ([C16MIM]Br) through physisorption and used as the sorbent of dispersive solid-phase extraction (DSPE). The sorbent was characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The retained analytes were eluted using 200 μL of methanol and then quantified by high performance liquid chromatography-ultraviolet detection (HPLC-UVD). The influences of extraction parameters of [C16MIM]Br-AL-DSPE on the BUs were thoroughly studied. Under the optimal conditions, good linearity was observed over the concentration range of 1–500 ng mL−1, with coefficients of determination greater than 0.99. The limits of detection (LODs) of the developed method were 0.14–0.21 ng mL−1 in water and 0.19–0.23 ng mL−1 in tea beverage samples. Satisfactory recoveries were achieved in the range of 72.8–89.3%, with relative standard deviations lower than 10%. Finally, the established [C16MIM]Br-AL-DSPE-HPLC-UVD method was successfully applied for the determination of BU residues in environmental water and tea beverage samples. [ABSTRACT FROM AUTHOR]

A novel in situ metathesis reaction combined with an ultrasound-assisted dispersive liquid–liquid microextraction based on the solidification of sedimentary ionic liquids (in situ UA-SSIL-DLLME) was combined with high-performance liquid chromatography (HPLC) to detect four triazole pesticides in water and juice samples. In this method, the hydrophobic ionic liquid [P4448][PF6], formed in situ by the hydrophilic ionic liquid [P4448]Br and the anion-exchange reagent KPF6, was used as the microextraction solvent. The extraction procedure was assisted by ultrasound at 50 W for 5 min. After centrifugation and cooling, [P4448][PF6] was sedimented at the bottom and easily collected by decanting the aqueous phase directly. Various parameters affecting the extraction efficiency, such as the quantity of [P4448]Br, the molar ratio of [P4448]Br to KPF6, salt addition, ultrasound time, centrifugation rate and time, and sample pH, were evaluated. Good linearities with correlation coefficients greater than 0.99 were obtained under the optimum conditions. The limits of detection varied between 0.90 and 1.38 μg L−1, and the enrichment factors were in the range of 94–101. The recoveries of these four triazole pesticides ranged from 85.18% to 91.14%, with relative standard deviations less than 4.86% and 5.87% for intra-day (n = 3) and inter-day (n = 3), respectively. The proposed method was then successfully applied to analyze the target compounds in environmental water and juice samples. [ABSTRACT FROM AUTHOR]

Two ionic liquid-coated-Fe3O4 magnetic particles (IL-Fe3O4 MPs) were developed for use in two types of dispersive micro-solid phase extraction (D-μ-SPE) for the high-performance liquid chromatographic analysis of clofentezine and chlorfenapyr in environmental water samples. Self-assembling IL-Fe3O4 MPs were used in D-μ-SPE as adsorbents. Two D-μ-SPE extraction methods, namely, direct dispersive micro-solid phase extraction (d-D-μ-SPE) and in situ solvent formation-based dispersive micro-solid phase extraction (ISF-D-μ-SPE), were proposed, using [C8MIM][PF6] to extract analytes through two pathways. Lower IL doses were required in the extraction process compared with those in other IL-based methods. Fe3O4 MPs can also be recycled and reused after extraction and are thus environmentally friendly. These newly developed methods were demonstrated to be feasible for use in the quantitation of clofentezine and chlorfenapyr at trace levels, with lower limit of detection values ranging from 0.4 to 0.5 ng mL−1 for d-D-μ-SPE and 0.4 ng mL−1 for ISF-D-μ-SPE. Finally, relative standard deviations of less than 6.0% were obtained. [ABSTRACT FROM AUTHOR]

Chalcohalides are attractive multifunctional candidates for new material due to their diverse crystal structures and the characteristics that come from the fusing of chalcogenides and halides. Here, we successfully synthesized a new Pb-based chalcohalide with multiple-halogens, namely, Pb 3 SBrI 3 , via a hydrothermal reaction using an organic chemical as the source of the sulfur. The Pb 3 SBrI 3 exhibits unique neutral [Pb 3 SBrI 3 ] ∞ layers composed of rich Pb-centered units including PbS 3 trigonal pyramids, PbSI 4 square pyramids, and PbBr 2 I 4 octahedra that are piled along the a -axis. Notably, the Pb 3 SBrI 3 is the first Pb-based chalcohalide featuring such a 2D structure. In this work, we examined in detail its synthesis, crystal structure, optical properties and theoretical calculation results.