Online coupling of in-tube solid phase microextraction (IT-SPME) with direct analysis in real time mass spectrometry (DART-MS) was realized for the first time and applied in the analysis of triazine herbicides in lake water and orange juice. We incorporated single-wall carbon nanotubes (SWNTs) into a polymer monolith containing methacrylic acid (MAA) and ethylene dimethacrylate (EDMA) to form a novel poly(methacrylic acid-co-ethylene dimethacrylate-co-single wall carbon nanotubes) (poly(MAA-EDMA-SWNT)) monolith, which was then used in IT-SPME for enrichment of six triazine herbicides from water samples. With the online combination of IT-SPME with DART-MS, the analytes desorbed from the monolith were directly ionized by DART and transferred into MS for detection, thus rapid determination was achieved. Compared with regular DART-MS method, this online IT-SPME-DART-MS method was more sensitive and reproducible, because of the IT-SPME procedures and the isotope-labeled internal standard used in the experiment. Six triazine herbicides were determined simultaneously using this method with good linearity (R(2) > 0.998). The limit of quantification (signal-to-noise ratio of S/N = 10) of the six herbicides were only 0.06-0.46 ng/mL. The proposed method has been applied to determine triazine herbicides in lake water and orange juice, showing satisfactory recovery (85%-106%) and reproducibility (relative standard deviation of RSD = 3.1%-10.9%).

AD -A-D' type pure organic molecule,n amed ODFRCZ, has unique triple-emission character covering fluorescence,p hosphorescence,a nd delayed fluorescence (DF). The phosphorescence of ODFRCZ has ar ather long lifetime of about 350 ms at room temperature.O ne dimer of ODFRCZ with enhanced parallel molecular packing acts more effectively to prompt ISC processes,w hichf urther generates room-temperature phosphorescence (RTP),o wing to the larger transition dipole moment and closer energy level between S 1 and T n .ODFRCZ is arare example of an organic RTPmolecule that shows dual-stimuli responsiveness of dualmode mechanochromism (fluorescence red-shift and RTP/DF on-off switch)a nd reversible crystal-state photochromism. This work may broaden the knowledge for stimuli-responsive RTPorganic molecules and lay the foundation for their widescale applications.Supportinginformation (synthesis procedures and molecularcharacterization of ODFRCZ/ODBTCZ, single crystal data, TD-DFT results, characterization of reversibility) and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

No abstract

Cysteine-functionalized metal-organic framework (MOF) was synthesized via a common and facile two-step method of in situ loading of Au nanoparticles on amino-derived MOF followed by l-cysteine (Cys) immobilization. Owing to the large specific surface area and ultrahigh hydrophilicity of this nanocomposite, excellent performance was observed in the enrichment of N-linked glycopeptides in both model glycoprotein and HeLa cell lysate. By using this nanocomposite, 16 and 31 glycopeptides were efficiently extracted from digest of horseradish peroxidase (HRP) and human serum immunoglobulin G (IgG), respectively. The short incubation time (5 min), large binding capacity (150 mg/g, IgG digest to material), good selectivity (1:50, molar ratio of IgG and bovine serum albumin (BSA) digest), high recovery (over 80%), and low detection limit (1 fmol) ensure the effectiveness and robustness of MIL-101(NH)@Au-Cys in complex HeLa cell lysate. As a result, 1123 N-glycosylation sites corresponding to 1069 N-glycopeptides and 614 N-glycoproteins were identified from the lysate. Compared with those of previously reported hydrophilic methods, to our knowledge, it was the best result. This work paves a new way for fast functionalization of MOF and also provides a novel idea for material design in sample preparation, especially in glycoproteome and related analysis.

Chiral separation is of great importance for drug development, pharmacology, and biology. Chiral metal-organic frameworks (MOFs) is a new class of porous solid materials with high surface area, large pore size, high chemical stability, uniformly structured cavities, and the availability of modification. The excellent properties of MOFs have attracted intense interest to explore their performance and mechanism in chiral separation. This review summarizes three synthetic strategies of chiral MOFs and their applications in enantioselective adsorption and chromatographic separation. All the experimental and molecular simulation results demonstrated that high enantioselectivity was strongly correlated with a close match between the size of the pore and chiral molecules.

No abstract

No abstract

MIL-101(Cr) is an excellent metal-organic framework with high surface area and nanoscale cavities, making it promising in solid-phase extraction. Herein, we used MIL-101(Cr) as a solid-phase extraction packing material combined with fast detection of direct analysis in real time mass spectrometry (DART-MS) for the analysis of triazine herbicides. After systematic optimization of the operation parameters, including the gas temperature of DART, the moving speed of the 1D platform, solvent for desorption, amount of MIL-101(Cr) extraction time, eluent volume and salt concentration, this method can realize the simultaneous detection of five kinds of triazine herbicides. The limits of detection were 0.1∼0.2 ng/mL and the linear ranges covered more than two orders of magnitude with the quantitation limits of 0.5∼1 ng/mL. Moreover, the developed method has been applied for the analysis of lake water samples and the recoveries for spiked analytes were in the range of 85∼110%. These results showed that solid-phase extraction with metal-organic frameworks is an efficient sample preparation approach for DART-MS analysis and could find more applications in environmental analysis.