Length-controlled hydrophobic CF3-COF as a highly efficient absorbent coating for dual-mode solid-phase microextraction of sixteen polycyclic aromatic hydrocarbons in water samples.

Polycyclic aromatic hydrocarbons (PAHs), a group of seriously hazardous environmental contaminants, have attracted extensive attention due to their carcinogenicity, genotoxicity, mutagenicity, and ubiquity. In this work, the excellent hydrophobic trifluoromethyl-enriched covalent organic framework (CF3-COF) was designed and synthesized as coating of solid-phase microextraction (SPME). The CF3-COF offered a high adsorption selectivity for PAHs, which could be attributed to the multiple interactions between the CF3-COF and PAHs, including hydrophobicity interaction, π-π and H bond interactions. Furthermore, headspace (HS) and direct immersion (DI) dual-mode solid-phase microextraction (HS/DI-SPME) were innovatively integrated as a dual-mode extraction by varying the length of SPME coating on stainless-steel, which could simultaneously and efficiently extract 16 PAHs with different volatile. Amazingly, the proposed strategy achieved fast adsorption for PAHs and shortened the adsorption equilibrium time to 15 min. By further integrating with gas chromatography tandem mass spectrometry (GC-MS/MS), PAHs could be detected in the range of 0.008-0.16 ng mL-1 with a quantitative limit of 0.029-0.47 ng mL-1, respectively. The recoveries of PAHs in water samples ranged from 80.84 to 117.67 %. This work indicates that the dual-mode CF3-COF-SPME is a promising candidate for the enrichment of multiple hazardous substances in complicated samples.

Functionalized magnetic metal organic framework nanocomposites for high throughput automation extraction and sensitive detection of antipsychotic drugs in serum samples.

Due to the complexity of biological sample matrix, the automated and high-throughput pretreatment technology is urgently needed for monitoring the antipsychotic drugs for mental patients. In this study, functionalized magnetic zirconium-based organic framework nanocomposites (Fe3O4@SiO2@Zr-MOFs) were successfully designed and synthesized by the layer-by-layer growth. Among them, Fe3O4@SiO2@UiO-67-COOH showed the best adsorption performance, and at the same time it exhibited excellent water dispersibility, high thermal stability, chemical stability and high hydrophobicity. Results of adsorption kinetics, isotherm and FT-IR showed that the adsorption process was dominated by chemical adsorption (hydrogen bond, electrostatic interaction, π-π interaction) and monolayer adsorption. Moreover, the smaller pore size improved the protein exclusion rate which reached 98.9-99.8%. Based on the above result, the synthesized magnetic nanoparticles were introduced to 96-well automatic extractor, antipsychotic drugs in 96 serum samples were automatically extracted within 9 min, which most greatly saved the time and labor costs and avoided artificial errors. By further integrating with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), antipsychotic drugs can be detected in the range of 0.2-3.0 ng mL-1 with a quantitative limit of 0.06-0.9 ng mL-1. The recoveries of antipsychotic drugs and their metabolites in serum ranged from 95.7% to 112.3% within 1.4-6.5% of RSD. These features indicate that the proposed method is promising for high throughput and sensitively monitoring of drugs and other hazardous substances.

[Determination of four bisphenol environmental hormone residues in infant serum by liquid chromatography-tandem mass spectrometry].

Bisphenols are important industrial raw materials that are widely used to produce plastic bottles (feeding bottles), infant cups, and food and beverage (milk powder) cans. Because of the estrogen-like effect of bisphenols, even low-dose intake of these compounds by trace migration affects normal hormone levels in the human body. Therefore, it is imperative to develop a rapid, accurate, and highly sensitive method for the determination of bisphenols in serum. In this study, methyl tert-butyl ether (MTBE) was used as the extraction solvent, and the liquid-liquid extraction pretreatment method was used for sample processing. A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was established for the simultaneous determination of bisphenol A (BPA), bisphenol B (BPB), bisphenol F (BPF), and bisphenol S (BPS) at trace levels in infant serum. The important parameters affecting the extraction efficiency, such as the extraction solvent, extraction time, and extraction solvent volume for the four bisphenol environmental hormones were optimized. Serum samples were extracted by MTBE at 40℃ for 15 min. The target compounds were separated on a Waters ACQUITY UPLC BEH C18 column (50 mm×2.1 mm, 1.7 µm) using ultrapure water and methanol solution containing 0.5 mmol/L ammonium acetate as the mobile phases, with gradient elution at a flow rate of 0.2 mL/min. Finally, the analytes were analyzed by HPLC-MS/MS in the negative ion mode. BPA, BPB, and BPS showed good linearity in the range of 0.25-100 µg/L, while BPF showed good linearity in the range of 1-100 µg/L. The correlation coefficients were 0.9929-0.9959, and the limits of detection for BPA, BPB, BPS, and BPF were 0.05, 0.05, 0.05, 0.5 µg/L, respectively. At the three spiked levels (5, 20, 100 µg/L), the average recoveries of BPA, BPB, BPS, and BPF ranged from 84.56% to 104.43%, and the relative standard deviations were less than 10%. The proposed method was successfully applied to the determination of bisphenol contents in 150 infant serum samples. BPA was detected in most serum samples, and the detection rates in the serum of boys and girls were 90.67% and 89.33%, respectively. The detection rates of BPF in the serum of boys and girls were 6.67% and 1.33%, respectively; the corresponding values for BPS were 5.33% and 16.00%. BPB was not detected. The proposed method has the advantages of simple operation, good recovery, and high precision, and it is suitable for the simultaneous determination of the four bisphenol environmental hormones in infant serum.