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• A fluffy phloroglucinol-urotropine porous polymer (PU-PP) was synthesized. • Miniaturized pipette tip solid phase extraction (PT-SPE) required only 3 mg PU-PP. • A PU-PP-PT-SPE-HPLC for simultaneous determination of four PAHs was developed. • The PU-PP-PT-SPE-HPLC method showed good practicability in lotus root samples. Polycyclic aromatic hydrocarbons (PAHs) posed a serious threat to food safety and human health due to long-term emission. In this work, a new method was established using phloroglucinol-urotropine porous polymer (PU-PP) in a pipette tip for solid phase extraction (PT-SPE) for the first time and used prior to determination of four PAHs (phenanthrene, anthracene, fluoranthene, and pyrene) in lotus roots. Synthesis of the PU-PP adsorbent was green compared with alternatives; urotropine was used as a cross-linker and ethanol–water as the solvent. PU-PP-based PT-SPE had the advantages of low solvent consumption, good purification, practicability, stability, and low-cost. The proposed pre-purification method offered low limits of detection (0.09–0.28 ng/g) and good recoveries (84.6–114.3 %, RSDs ≤ 5.6 %) for determination of the four PAHs, which were detected at trace concentrations in samples. This new method provides an alternative for monitoring trace pollutants in aquatic plant ingredients. [ABSTRACT FROM AUTHOR]

A step-index chalcogenide fiber with a rectangular core and a circular cladding was fabricated through an approach that combines an extrusion technique and a multiple-stage rod-in-tube method. This fiber has a Ge 12 As 24 Se 64 glass core with a size of ~2.8 μm × 5.9 μm, and a Ge 10 As 24 S 66 glass cladding with a diameter of ~220 μm, and shows a relatively large birefringence. When ~10 cm long fiber was pumped at 4.0 μm with 330 fs pulses, ~2.2–9.5 μm supercontinuum with a flatness of 20 dB and a polarization extinction ratio of ~10 dB was generated. • A chalcogenide glass fiber with a rectangular core is designed. • The fiber is fabricated by an extrusion technique and a rod-in-tube method. • The fiber shows a background loss of about 3.1 dB/m in the mid-infrared. • Polarized ~2.2–9.5 μm supercontinuum is generated in the fiber. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ant nest-like porous imprinting resin (IL-MIPPR) was fabricated for the first time. • IL-MIPPR has an economical, high yield, hierarchical porous, and large surface area. • IL-MIPPR − DSPE completed the extraction process of five PCBs in milk in about 10 min. • An IL-MIPPR − DSPE − GC–MS/MS was developed for the determination of PCBs in milk. Polychlorinated biphenyls (PCBs) are persistent toxic, organic chemicals that tend to accumulate in the food chain. This study reports the rapid and selective extraction and determination of PCBs (PCB81, 153, 105, 126, and 157) in milk samples by a dispersive solid-phase extraction (DSPE) coupled with gas chromatography-tandem mass spectrometry (GC–MS/MS). An ionic liquid-molecularly imprinted porous resin (IL-MIPPR) as a DSPE adsorbent was synthesized from m -aminophenol, formaldehyde, and 2,2′-benzidinedisulfonic acid as the monomer, crosslinker, and virtual template, respectively. The IL-MIPPR had a fast mass transfer (1.0 min) and good selectivity (imprinting factors of 1.8–3.0). The IL-MIPPR − DSPE − GC–MS/MS method exhibited good linearity (R2 ≥ 0.9995), the limit of detections (LODs) < 0.6 pg/g, and the recoveries ranged from 82.8 % to 106 % with relative standard deviations ≤ 6.6 %. This method is thus better than previously reported methods in terms of the LOD, the adsorbent dosage, and the extraction time. [ABSTRACT FROM AUTHOR]

• A three-dimensional graphene/MWCNT composite adsorbent was synthesized. • Graphene/MWCNT was used as a new adsorbent for extraction of 17β-estradiol. • The PT-SPE requiring less sample, adsorbent and organic reagent consumption. • The established method has good purification ability, sensitivity and accuracy. The illegal addition and abuse of 17β-estradiol (E2) in food has led to its accumulation in the body through the food chain, resulting in adverse effects on the human body through interference with the endocrine system. Because milk and dairy products are major components of the human diet, screening as well as quantitative analysis of E2 in these food types is important. In this work, a three-dimensional graphene/multi-walled carbon nanotube composite was synthesized and applied to a home-made pipette-tip solid-phase extraction cartridge and coupled with high-performance liquid chromatography-fluorescence detection to determine E2 in milk. The established method showed good linearity in the range of 5–250 ng mL−1 with correlation coefficient of 0.9998. The detection limit and quantitation limit were 0.7 and 2.3 ng mL−1, respectively. The repeatability and intermediate precision, expressed as the coefficient of variation were 3.7% and 6.0%, respectively. The accuracy of the method was investigated by recovery experiments with milk at three spiked levels (25, 100, and 250 ng mL−1), where the recoveries were in the 88.4–108.9% range with relative standard deviations ≤5.5%. The proposed method has the advantage of requiring less adsorbent (only 1.0 mg) and less organic reagent (1.0 mL of washing solvent, 1.2 mL of elution solvent) and exhibits excellent purification ability, with high sensitivity and accuracy, and was successfully applied for the determination of E2 in milk products. [ABSTRACT FROM AUTHOR]

Ga 8 Sb 32 S 60 chalcogenide glass is modified by arsenic (As) to further improve its thermal stability against crystallization, and the 3–5 μm mid-infrared (MIR) luminescent properties of Dy 3+ ions in the modified glasses are studied. Furthermore, fibers consisting of Dy 3+ -doped glass core and undoped glass cladding are drawn, and the transmission losses and MIR luminescence of the fibers are investigated. The substitution of a small part of Sb by As could remarkably improve the thermal stability of the glass without leading to significant changes on the optical transparency and the effective phonon energy. Although Dy 3+ addition has a negative effect on the thermal stability of the modified glasses, the doped glasses are still sufficiently stable for fiber drawing. Dy 3+ ions in the modified glasses show strong MIR emissions around 2.95 μm and 4.40 μm with high quantum efficiencies and large stimulated emission cross sections. The fabricated fibers exhibit a background loss of less than 2 dB/m in the 2–6 μm spectral range and intense MIR emissions. [ABSTRACT FROM AUTHOR]

Novel Ga–Sb–S chalcogenide glasses doped with different amount of Dy 3+ ions were prepared. Their thermal stability, optical properties, and mid-infrared (MIR) emission properties were investigated. The glasses show good thermal stability, excellent infrared transparency, very low phonon energy (∼306 cm −1 ), and intense emissions centered at 2.95, 3.59, 4.17 and 4.40 μm. Three Judd–Ofelt intensity parameters (Ω 2 = 8.51 × 10 −20 cm 2 , Ω 4 = 2.09 × 10 −20 cm 2 , and Ω 6 = 1.60 × 10 −20 cm 2 ) are obtained, and the related radiative transition properties are evaluated. The high quantum efficiencies and large stimulated emission cross sections of the MIR emissions (88.10% and 1.11 × 10 −20 cm 2 for 2.95 μm emission, 75.90% and 0.38 × 10 −20 cm 2 for 4.40 μm emission, respectively) in the Dy 3+ -doped Ga–Sb–S glasses make them promising gain materials for the MIR lasers. [ABSTRACT FROM AUTHOR]