Preparation of polysulfone materials on nickel foam for solid-phase microextraction of floxacin in water and biological samples

Superhydrophilic Triazine-Based Covalent Organic Frameworks via Post-Modification of FeOOH Clusters for Boosted Photocatalytic Performance

The triazine-based covalent organic frameworks (tCOF), an intriguing subtype of COFs, are expected as highly promising photocatalysts for various photocatalytic applications owing to their fully conjugated structures and nitrogen-rich skeletons. However, the inherent hydrophobicity and fast recombination of photoexcited electron-hole pairs are two main factors hindering the application of tCOF in practical photocatalytic reactions. Here, a post-synthetic modification strategy to fabricate superhydrophilic tCOF-based photocatalysts is demonstrated by in situ growing FeOOH clusters on TaTz COF (TaTz-FeOOH) for efficient photocatalytic oxidation of various organic pollutants. The strong polar FeOOH endows TaTz-FeOOH with good hydrophilic properties. The well-defined heterogeneous interface between FeOOH and TaTz allows the photoelectrons generated by TaTz to be consumed by Fe (III) to transform into Fe (II), synergistically promoting the separation of holes and the generation of free radicals. Compared with the unmodified TaTz, the optimized TaTz-FeOOH (1%) shows excellent photocatalytic performance, where the photocatalytic degrade rate (k) of rhodamine B is increased by about 12 times, and the degradation rate is maintained at 99% after 5 cycles, thus achieving efficient removal of quinolone antibiotics from water. This study provides a new avenue for the development of COF-based hydrophilic functional materials for a wide range of practical applications.

Development of a rapid efficient solid-phase microextraction: An overhead rotating flat surface sorbent based 3-D graphene oxide/ lanthanum nanoparticles @ Ni foam for separation and determination of sulfonamides in animal-based food products

In this study, an overhead rotating flat surface sorbent based solid-phase microextraction was developed as a rapid and efficient method for simultaneous separation and determination of sulfonamides in animal based-food products. 3D graphene oxide/ lanthanum nanoparticles @ Ni foam was introduced as a novel selective sorbent. SEM-EDX and FT-IR techniques were applied for characterization of the sorbent. At optimum conditions, the linear ranges of 0.4-700.0 (µg L^-1), 0.3-900.0 (µg L^-1), and 0.25-500 (µg L^-1) and the enrichment factors of 606.8, 604.3, 608.9 were obtained for SDZ, SMX, and SMZ, respectively. The LOD (S/N = 3) of 0.14, 0.11, 0.08 (µg L^-1) were achieved for SDZ, SMX, and SMZ, respectively. The intra-day and inter-day precision (%) (five days, n = 7) for the concentration of 100 µg L^-1 were less than 4.3 and 3.8, respectively. The recoveries over 90.0 % revealed high capability of the method for utilization in complex matrixes.

Impact of biochar-induced vertical mobilization of dissolved organic matter, sulfamethazine and antibiotic resistance genes variation in a soil-plant system

The migration risk of antibiotic and antibiotic resistance genes (ARGs) have attracted lots of attentions due to their potential threaten to public health. Strategies to reduce their vertical mobilization risk are urgently required for groundwater safety and human health. Biochar enjoys numerous interests due to its excellent sorption affinity. However, little was known about the efficacy of biochar amendment in impeding the vertical mobilization of antibiotic and ARGs. To fill this gap, a column study was carried out to investigate biochar-induced variations in the leaching behavior of dissolved organic matter (DOM), sulfamethazine (SMZ) and ARGs. Results showed that biochar addition enhanced DOM export from soil, changed its composition and impeded the vertical transport of SMZ. Biochar amendment could effectively decrease the occurrence of extracellular and intracellular sul2 in soil and impede its vertical transportation, however, it did not work out with sul1 gene. Structural equation modeling analysis demonstrated that the abundance of sul2 was significantly controlled by SMZ concentration, while the primary drivers of sul1 were SMZ concentration and DOM content. These results indicated the failure in inhibiting the vertical transfer of sul1 under biochar amendment and highlighted the important role of DOM in the leaching of soil ARGs.

Reduced graphene oxide coated nickel foam for stir bar sorptive extraction of benzotriazole ultraviolet absorbents from environmental water

The use of porous carrier and coating sorbents in stir bar sorptive extraction (SBSE) contributes to the improvement of extraction efficiency and dynamics. Herein, porous nickel foam (NF) with large surface area and magnetic property was used as the carrier of stir bar. NF was added into the mixture of graphene oxide (GO) and reducing agent, and reduced graphene oxide (RGO) coating was obtained on the surface of NF substrate by in situ hydrothermal reduction. The characterization results of Fourier transform infrared spectroscopy, X-ray power-diffraction and scanning electron microscope showed that GO was partially reduced into RGO, and the RGO coating was uniformly loaded on the NF surface. The obtained RGO-NF composite was used as the stir bar coating for the analysis of six benzotriazole (BZTs) UV absorbents. The extraction efficiency was between 48 and 64% for six BZTs. RGO-NF stir bar exhibited faster adsorption/desorption kinetics than commercial polydimethylsiloxane coated stir bar (50 min vs 120/360 min) due to its porous structure and large specific surface area. On this basis, a method of RGO-NF coated stir bar sorptive extraction combined with high performance liquid chromatography (HPLC)-DAD was established for the determination of six BZTs. Under the optimized conditions, the limits of detection were 0.33-0.50 μg/L for six target BZTs, and the linear range was 1-100 μg/L. The proposed method merits good ability to resist matrix and was used to analyze six BZTs in environmental water samples. The recoveries of target BZTs were obtained within 83.0-112% in the spiked East Lake water and 97.0-111% in the spiked Yangtze River water, respectively.

A restricted access molecularly imprinted polymer coating on metal–organic frameworks for solid-phase extraction of ofloxacin and enrofloxacin from bovine serum

A restricted access molecularly imprinted polymer (RAMIP) crosslinked with bovine serum albumin (BSA) was prepared on the surface of the mesoporous UiO-66-NH₂ metal–organic framework (MOF). The surface morphology, imprinting behavior, and protein exclusion properties of UiO-66-NH₂@RAMIP@BSA were investigated. The maximum adsorption capacity was 50.55 mg g⁻¹ for ofloxacin, with a 99.4% protein exclusion rate. Adsorption equilibrium was reached in 9 min. Combined with RP-HPLC, a solid-phase extraction column filled with UiO-66-NH₂@RAMIP@BSA was used to selectively enrich and analyze ofloxacin and enrofloxacin antibiotics from bovine serum with recoveries of 93.7–104.2% with relative standard deviations of 2.0–4.5% (n = 3). The linear range and the limit of detection were 0.1–100 μg mL⁻¹ and 15.6 ng mL⁻¹, respectively. These results suggest that UiO-66-NH₂@RAMIP@BSA is an efficient pretreatment adsorbent for biological sample analysis.

A restricted access molecularly imprinted polymer (RAMIP) crosslinked with bovine serum albumin (BSA) was prepared on the surface of the mesoporous UiO-66-NH₂ metal–organic framework (MOF).