Oxygen atmosphere enhances ball milling remediation of petroleum-contaminated soil and reuse as adsorptive/catalytic materials for wastewater treatment.

Ball milling is an environmentally friendly technology for the remediation of petroleum-contaminated soil (PCS), but the cleanup of organic pollutants requires a long time, and the post-remediation soil needs an economically viable disposal/reuse strategy due to its vast volume. The present paper develops a ball milling process under oxygen atmosphere to enhance PCS remediation and reuse the obtained carbonized soil (BCS-O) as wastewater treatment materials. The total petroleum hydrocarbon removal rates by ball milling under vacuum, air, and oxygen atmospheres are 39.83%, 55.21%, and 93.84%, respectively. The Langmuir and pseudo second-order models satisfactorily describe the adsorption capacity and behavior of BCS-O for transition metals. The Cu2+, Ni2+, and Mn2+ adsorbed onto BCS-O were mainly bound to metal carbonates and metal oxides. Furthermore, BCS-O can effectively activate persulfate (PDS) oxidation to degrade aniline, while BCS-O loaded with transition metal (BCS-O-Me) shows better activation efficiency and reusability. BCS-O and BCS-O-Me activated PDS oxidation systems are dominated by 1O2 oxidation and electron transfer. The main active sites are oxygen-containing functional groups, vacancy defects, and graphitized carbon. The oxygen-containing functional groups and vacancy defects primarily activate PDS to generate 1O2 and attack aniline. Graphitized carbon promotes aniline degradation by accelerating electron transfer. The paper develops an innovative strategy to simultaneously realize efficient remediation of PCS and sequential reuse of the post-remediation soil.

Doped nanomaterial facilitates 3D printing target plate for rapid detection of alkaloids in laser desorption/ionization mass spectrometry.

This work aims to rapidly detect toxic alkaloids in traditional Chinese medicines (TCM) using laser desorption ionization mass spectrometry (LDI-MS). We systematically investigated twelve nanomaterials (NMs) as matrices and found that MoS2 and defect-rich-WO3 (D-WO3) were the best NMs for alkaloid detection. MoS2 and D-WO3 can be used directly as matrices dipped onto conventional ground steel target plates. Additionally, they can be conveniently fabricated as three-dimensional (3D) NM plates, where the MoS2 or D-WO3 NM is doped into resin and formed using a 3D printing process. We obtained good quantification of alkaloids using a chemothermal compound as an internal standard and detected related alkaloids in TCM extracts, Fuzi (Aconiti Lateralis Radix Praeparata), Caowu (Aconiti Kusnezoffii Radix), Chuanwu (Aconiti Radix), and Houpo (Magnoliae Officinalis Cortex). The work enabled the advantageous "dip and measure" method, demonstrating a simple and fast LDI-MS approach that achieves clean backgrounds for alkaloid detection. The 3D NM plates also facilitated mass spectrometry imaging of alkaloids in TCMs. This method has potential practical applications in medicine and food safety. Doped nanomaterial facilitates 3D printing target plate for rapid detection of alkaloids in laser desorption/ionization mass spectrometry.

Imidazolium-based mass tags for protein biomarker detection using laser desorption ionization mass spectrometry.

Novel imidazolium-based mass tags (IMTs) were designed, synthesized and applied to simultaneous in situ analysis of multiple biomarkers on less than 10 cells. The high sensitivity, flexible extensibility and excellent distinguishability of IMTs open new avenues for designing common mass tag templates suitable for mass spectrometric immunoassay and provide an ideal option for multiplex-sensitive detection at the cellular scale.

Thermal desorption bridged the gap between dielectric barrier discharge ionization and dried plasma spot samples for sensitive and rapid detection of fentanyl analogs in mass spectrometry.

The urgent threat of new psychoactive substances worldwide promotes rapid detection and identification demand for public security. Ambient ionization mass spectrometry (AIMS) has become mainstream among various detection techniques. Still, scant successful applications have been fulfilled toward dried blood spot (DBS) or plasma spot (DPS) as an easy-to-implement sampling format in AIMS. This work bridged the gap between dielectric barrier discharge ionization mass spectrometry (DBDI-MS) and DPS/DBS samples by thermal desorption (TD) assistance. It made the impossible mission of direct DBDI-MS measurement on DPS/DBS samples containing fentanyl analogs (FTNs) possible. Guided by finite element simulations and a customized three-dimensional printing interface, we constructed a semi-covered flat-TD surface for sufficient desorption and ionization of FTNs from DPS/DBS samples without any sample pretreatment or sample separation. We successfully quantified eight FTNs in DPS samples using deuterated fentanyl as internal standard by triple quadrupole tandem mass spectrometry (MS/MS) and proved its practical applicability in the fentanyl-exposed rat plasma samples. This DBDI-TD-MS method also fits well with DBS samples, and it only took 20 s to analyze each sample. Further, based on summarized fragmentation characteristics of twenty FTNs, we established a backbone alerting ion-guided screening rule for suspect screening of FTNs in DPS samples via quadrupole time-of-flight MS/MS and built a chemometric approach for convenient mutual verification of screening "unknown" artificial samples. We hope this ideal DBDI-TD-MS method finds its valuable role in national security, doping control, and public health for routine large-scale analysis or on-site detection.

Remediation of petroleum-contaminated soil by ball milling and reuse as heavy metal adsorbent.

A simple mechanochemical (MC) method is used to treat petroleum-contaminated soil and prepare a heavy metal adsorbent in one step. XRD, Raman, FT-IR, VSM, BET, and XPS were used to characterize the adsorbent. After MC treatment, the dissolved total petroleum hydrocarbons of the adsorbent is less than 1 mg·L-1, and a porous structure and carbonization phenomenon are evident. The specific surface area and cumulative void volume increase, and the adsorption pore size decreases. On the surface of soil, the percentages of iron oxides, carbonates, CO, -C-O-H, -COOH, and π unsaturated bonds increase. The Langmuir model shows that the maximum adsorption capacity of Pb2+, Cu2+, Cd2+, and Zn2+ are 338.58, 51.61, 32.34, and 25.05 mg·g-1, respectively. The pseudo-second-order kinetic model fits the Pb adsorption process, indicating the domination of chemical adsorption. GC-MS shows that petroleum hydrocarbons are completely degraded. The Tessier continuous extraction result shows that heavy metals are bound to carbonate, iron manganese oxide, and organic matter. The MC treatment achieves deep cleanup and resource utilization of petroleum-contaminated soil through the formation of amorphous carbon, carbonates, and iron oxides on the surface of soil particles. The material is magnetic and can be recycled when used in wastewater treatment.

Photo-Fenton superwettable NiFe2O4/TA/PVDF composite membrane for organic pollutant degradation with successively oil-in-water separation.

With regard to the treatment of multicomponent wastewaters, to construct multifunctional super-wetting membranes is highly attractive in current decade. In this work, a low-cost and novel NiFe2O4/TA/PVDF composite membrane was fabricated via a facile in-situ deposition method under vacuum system. In which, photo-response NiFe2O4 nanoparticles were immobilized on the surface of flexible PVDF base membrane via hydrophilic tannic acid (TA) as the binder. The resulting composite membrane exhibited a special superwettability of superamphilicity in air and underwater superoleophobicity with a nanoscale rough surface structure. One the one hand, NiFe2O4/TA/PVDF membrane can be used a reusable catalyst in Photo-Fenton degradation of organic dyes with high efficiency. On the other hand, the composite membrane can effectively separate emulsified oils from representative oil-in-water emulsions with excellent separation efficiency all above 99 % and relatively high flux (880-1525 Lm-2h-1 bar-1). More importantly, NiFe2O4/TA/PVDF composite membrane showed satisfactory processing efficiency, anti-fouling property and excellent reusability in deal with the mixed organic pollutants (water-insoluble emulsified oils and water-soluble organic dyes) existed in one aqueous system, which followed the procedure of initially photo-Fenton degradation of organic dyes emulsion and successively separation the remaining emulsion over the recovered membrane. This successful development of high-performance NiFe2O4/TA/PVDF composite membrane will provide a new candidate for both oil/water separation and organic wastewater treatment, as well as promote the utilization of spinel ferrites in the construction of multifunctional membrane for environmental purification.

Synthesis of Porphyrin Zr-MOFs for the Adsorption and Photodegradation of Antibiotics under Visible Light.

The release of antibiotics into the water environment can pose a serious threat to human and ecological health, so it is of great significance to effectively remove antibiotics from wastewater. In this work, porphyrinic zirconium metal-organic framework material, PCN-224, was first explored for the adsorption removal of antibiotics from water using tetracycline (TC) and ciprofloxacin (CIP) as examples. We prepared a series of PCN-224 with different particle sizes (150 nm, 300 nm, 500 nm, and 6 µm). Benefiting from the huge surface area (1616 m2 g-1), the 300 nm-PCN-224 sample had the best adsorption properties for TC and CIP. Remarkably, it exhibits fast removal rates and high adsorption capacities of 354.81 and 207.16 mg g-1 for TC and CIP, respectively. The adsorption of TC and CIP in 300 nm-PCN-224 is consistent with the pseudo-second-order kinetic model and Langmuir isotherm model, which indicates that the adsorption can be regarded as homogeneous monolayer chemisorption, and the adsorption is exothermic, which has been confirmed by thermodynamic studies. Under visible-light irradiation, 300 nm-PCN-224 exhibited high photocatalytic activity for TC and CIP. The adsorption studies confirmed that the adsorption of adsorbates takes place via the formation of hydrogen bonding, π-π interactions, and electrostatic attraction. In addition, the adsorbent can be simply regenerated by photocatalysis under visible light, and the adsorption-desorption efficiency is still above 85% after repeated use five times. The work of MOFs to remove antibiotics from water shows that MOFs have great potential in this field and are worthy of further study.

Bifunctional NiAlFe LDH-coated membrane for oil-in-water emulsion separation and photocatalytic degradation of antibiotic.

A new NiAlFe layered double hydroxide/polydopamine/polyvinylidene fluoride (NiAlFe LDH/PDA/PVDF) membrane was fabricated by in-situ growth of LDH on the PDA modified PVDF membrane. The as-prepared membrane possesses a nano/microscale rough structural surface and displays the superior wettability of superhydrophilicity in air and underwater superoleophobicity. Combining the favourable features of superwettability and hierarchical rough structure, the NiAlFe LDH/PDA/PVDF membrane could effectively separate a series of oil-in-water emulsions with high efficiency (>99%) and high permeation flux (925-1913 L m-2 h-1 bar-1). Besides, owing to the light harvest ability of NiAlFe LDH, the relevant membrane also can be applied as a photocatalysis paper for the light-driven treatment of antibiotic residue in aqueous solution. In which, NiAlFe LDH/PDA/PVDF membrane can effectively degrade typical antibiotic tetracycline within 20 min under UV light irradiation, exhibiting excellent photocatalytic activity. In addition, cyclic experiments demonstrate that NiAlFe LDH/PDA/PVDF membrane has excellent stability and reusability both in oil-in-water emulsion separation and photocatalytic reaction. In general, the findings of this research demonstrate that photo-response LDH modified membranes have potential multiple applications in wastewater treatment.

MALDI-TOF/TOF tandem mass spectrometry imaging reveals non-uniform distribution of disaccharide isomers in plant tissues.

Mass spectrometry imaging (MSI) is a powerful technique for investigating the biomolecular locations within tissues. However, the isomeric compounds are rarely distinguished due to inability of MSI to differentiate isomers in the probing area. Coupling tandem mass spectrometry with MSI can facilitate differentiating isomeric compounds. Here MALDI-TOF/TOF tandem mass spectrometry imaging approach was applied to probing the spatial distributions of isomeric disaccharides in plant tissues. First, MS/MS imaging analysis of disaccharide-matrix droplet spots demonstrated the feasibility of distinguishing isomeric species in tissues, by measuring the relative intensity of specific fragments. Then, tandem MS imaging of disaccharides in onion bulb tissues indicated that sucrose and other unknown non-sucrose disaccharides exhibit heterogeneous locations throughout the tissues. This method enables us to image disaccharide isomers differentially in biological tissues, and to discover new saccharide species in plant. This work also emphasizes the necessity of considering isobaric compounds when interpreting MSI results.

Fe3O4-Loaded g-C3N4/C-Layered Composite as a Ternary Photocatalyst for Tetracycline Degradation.

A ternary photocatalyst, Fe3O4-loaded g-C3N4/C-layered composite (g-C3N4/C/Fe3O4) was fabricated by a facile sonication and in situ precipitation technique. Carbon nanosheets were prepared using the remaining non-metallic components of waste printed circuit boards as carbon sources. In this hybrid structure, g-C3N4 was immobilized on the surfaces of carbon nanosheets to form a layered composite, and 10-15 nm Fe3O4 nanoparticles are uniformly deposited on the surface of the composite material. The photocatalytic performance of the catalyst was studied by degrading tetracycline (TC) under simulated sunlight. The results showed that the photoactivity of the g-C3N4/C/Fe3O4 composite to TC was significantly enhanced, and the degradation rate was 10.07 times higher than that of pure g-C3N4, which was attributed to Fe3O4 nanoparticles and carbon nanosheets. Carbon sheets with good conductivity are an excellent electron transporter, which promotes the separation of photogenerated carriers and the Fe3O4 nanoparticles can utilize electrons effectively as a center of oxidation-reduction. Moreover, a possible photocatalytic mechanism for the excellent photocatalytic performance was proposed.

High-Throughput Single-Cell Immunoassay in the Cellular Native Environment Using Online Desalting Dual-Spray Mass Spectrometry.

Single-cell mass spectrometry (MS) remains challenging in the analysis of cells in the native environment due to the severe ion suspension from nonvolatile salts. Synchronous desalting and ionization would be ideal to both ensure the native environment and remove the salt interference. Here, a novel dual-spray ionization technique combining electrospray and nanoelectrospray ionization (ESI-nESI) was developed, enabling highly efficient online desalting during the ionization process. In situ detection of cell surface proteins from the intact cells in phosphate buffer saline (PBS) was achieved by dual ESI-nESI MS with the help of an MS-based immunoassay using rhodamine-based mass tags. These mass tags were confirmed to be highly competitive during desalting, which improved the protein detection sensitivity to a single-cell level. Through the combination of the single-cell immunoassay with ESI-nESI MS, the important surface protein markers, cancer antigen 125, in two cancer cell lines (OVCAR-3 and MCF-7) suspended in the PBS buffers were screened in a high-throughput cytometric mode, along with some proposed cellular endogenous lipids. The ESI-nESI MS system is promising for multidimensional organic mass cytometric analysis in the cellular native environment for clinical use and many basic biology researches.

Microwave-assisted synthesis of 3D Bi2MoO6 microspheres with oxygen vacancies for enhanced visible-light photocatalytic activity.

Oxygen vacancies (OVs) defects in metal oxide-based photocatalysts play a crucial role in improving the charge carrier separation efficiencies to enhance the photocatalytic performances. In this work, OVs were introduced in 3D Bi2MoO6 microspheres through a facile and fast microwave-assisted method via the modulation of tetramethylethylenediamine (TMEDA). EPR, Raman and XPS results demonstrated that large amounts of oxygen vacancies were formed on the surface of BMO microspheres. The photocatalytic properties of the samples were studied by degradation of tetracycline (TC) under visible light. The optimal Bi2MoO6 with OVs exhibited optimum photocatalytic activity, and the degradation rate was 7.0 times higher than that of pristine Bi2MoO6. This enhancement can be attributed to the 3D structure furnishing more surface active sites and suitable OVs defects favoring the electron-hole separation. Moreover, the defective Bi2MoO6 microspheres exhibit high stability because the photocatalytic activity remains almost unchanged after 5 cycles, making them favorable for practical applications. Finally, a possible visible light photocatalysis mechanism for the degradation of TC was tentatively proposed.

Microwave Solvothermal Synthesis of Three-Dimensional Bi2MoO6 Microspheres with Enhanced Photocatalytic Activity.

In this study, three-dimensional (3D) Bi2MoO6 microspheres were successfully fabricated by a facile, rapid, and mild microwave solvothermal strategy for the first time. The resultant 3D Bi2MoO6 microspheres exhibited superior adsorption capacity and photocatalytic efficiency in the degradation of the representative antibiotic ciprofloxacin under visible light, for which the reaction kinetic rate constant is 7.5 times as high as that of the as-synthesized zero-dimensional Bi2MoO6 nanoparticles. The 3D hierarchical porous structure and the high Brunauer-Emmett-Teller surface area providing abundant reactive sites mainly contributed to the enhanced photocatalytic activity. The results highlight the feasibility of 3D Bi2MoO6 microspheres as an efficient visible-light-responsive photocatalyst for antibiotic removal in an aqueous system.

Tracing and elucidating visible-light mediated oxidation and C-H functionalization of amines using mass spectrometry.

The co-existing mechanism of visible light mediated direct oxidation and C-H functionalization of amines was investigated by capturing all the intermediates using online mass spectrometry. The two-step dehydrogenation of amine involving a proton coupled electron transfer (PCET) process was revealed for the first time.

Facile Fabrication of C-TiO2 Nanocomposites with Enhanced Photocatalytic Activity for Degradation of Tetracycline.

Visible-lightdriven C-TiO2 nanocomposites were prepared via a simple calcination and acid etching process. The C-TiO2 nanocomposites were characterized by X-ray photoelectron spectroscopy, Raman spectroscopy, X-ray diffraction, transmission electron microscopy, and high-resolution TEM. The results showed that TiO2 nanoparticles were combined with a porous carbon layer through surface C-O groups, which facilitates the strong interface interaction. The interface combination of nano-TiO2 and carbon material increases the specific surface area of nano-TiO2, widens the range of light response, and improves the efficiency of light-induced electron migration. The visible-light photocatalytic activity of the prepared photocatalyst was evaluated by the decomposition of tetracycline aqueous solution. Compared with that of pure TiO2, the photocatalytic activity of C-TiO2 nanocomposites was significantly improved. Furthermore, a possible photocatalytic mechanism was also tentatively proposed. This work can promote the development of active photocatalysts under solar light for the photodegradation of environmental pollutants.

Mass, Size, and Density Measurements of Microparticles in a Quadrupole Ion Trap.

The physical properties of microparticles, such as mass, size, and density, are critical for their functions. The comprehensive characterization of these physical parameters, however, remains a fundamental challenge. Here, we developed a particle mass spectrometry (PMS) methodology for determining the mass, size, and density of microparticles simultaneously. The collisional cross-section (CCS) and mass spectrometry (MS) measurements were performed in a single quadrupole ion trap (QIT), and the two modes can be switched easily by tuning the electric and gas hydrodynamic fields of the QIT. The feasibility of the method was demonstrated through a series of monodispersed polystyrene (PS) and silica (SiO2) particle standards. The SiO2/polypyrrole core-shell particles were also successfully characterized, and the measured results were verified by using conventional methods.

Oxidative Degradation of Dimethyl Phthalate (DMP) by the Fe(VI)/H2O2 Process.

This study investigates the degradation of dimethyl phthalate (DMP) with hydrogen peroxide and ferrate (Fe(VI)) under various reaction conditions. The results showed that the optimum conditions for dimethyl phthalate removal from water were as follows: (a) pH 7.0 and (b) the original molar ratio of [Fe(VI)]/[H2O2]/[DMP] equal to 10:2:1. Under the optimum conditions, the degradation rate of DMP can reach 89.7% in 360 min. Furthermore, 2,5-dihydroxybenzaldehyde, isophthalic acid, 2-ethylhexanol, oxalic acid, 2,6-dihydroxybenzoic acid, 2,6-dihydroxybenzaldehyde, 2,5-dihydroxybenzoic acid, and monomethyl phthalate were identified as the degradation intermediates, and degradation pathways were proposed.

Hybrid methods of surface plasmon resonance coupled to mass spectrometry for biomolecular interaction analysis.

Combining mass spectrometry (MS) with surface plasmon resonance (SPR) makes it possible to identify the chemical structures of the interacting molecules studied by SPR. Different approaches for coupling surface plasmon resonance sensors to mass spectrometry were developed. This article aims to summarize the established approaches and their applications to study biomolecular interactions. Three representative interactions were reviewed: protein-protein interactions, enzyme-substrate/inhibitor interactions, and protein-small molecule interactions.

Mass Spectrometry Genotyping of Human Papillomavirus Based on High-Efficiency Selective Enrichment of Nanoparticles.

This work developed a novel spermine-modified nanodiamonds (SP-NDs)-based method to selectively enrich oligonucleotides for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) of human papillomavirus (HPV) virus. Our results showed that SP-NDs can effectively extract and enrich DNA oligonucleotides from sodium dodecyl sulfonate and urea solution. In addition, SP-NDs can also selectively extract oligonucleotides from enzymes digestion products of polymerase chain reaction-restriction fragment mass polymorphism (PCR-RFMP) of HPV virus. Then, the extract can be detected by MALDI-TOF MS directly without further purification. According to the MS results, the HPV genotyping can be achieved. More importantly, with SP-NDs extraction, clinical samples infected with HPV genotype 16 and 18 can be identified. The described method shows great advantages of simplicity, high selectivity, and good reliability in real clinical samples. Due to our methods improvement on DNA enrichment, extraction and purification, the PCR-based MALDI-TOF MS for the analysis of oligonucleotides maybe become more rapid, sensitive, and high-throughput, is promising for analysis for DNA methylation, single-nucleotide polymorphisms, and other virus typing.

Mass spectrometry imaging of the in situ drug release from nanocarriers.

It is crucial but of a great challenge to study in vivo and in situ drug release of nanocarriers when developing a nanomaterial-based drug delivery platform. We developed a new label-free laser desorption/ionization mass spectrometry (MS) imaging strategy that enabled visualization and quantification of the in situ drug release in tissues by monitoring intrinsic MS signal intensity ratio of loaded drug over the nanocarriers. The proof of concept was demonstrated by investigating the doxorubicin (DOX)/polyethylene glycol-MoS2 nanosheets drug delivery system in tumor mouse models. The results revealed a tissue-dependent release behavior of DOX during circulation with the highest dissociation in tumor and lowest dissociation in liver tissues. The drug-loaded MoS2 nanocarriers are predominantly distributed in lung, spleen, and liver tissues, whereas the accumulation in the tumor was unexpectedly lower than in normal tissues. This new strategy could also be extended to other drug-carrier systems, such as carbon nanotubes and black phosphorus nanosheets, and opened a new path to evaluate the drug release of nanocarriers in the suborgan level.