Macroporous Network Research Articles

Metal-Organic Framework for Emulsifying Carbon Dioxide and Water.

Forming emulsions of carbon dioxide (CO2 ) and water can largely expand the utility of CO2 . Herein we propose for the first time the utilization of a metal-organic framework (MOF) for emulsifying CO2 and water. Owing to the hybrid composition, MOF particles can easily assemble at the CO2 /water interface to create a rigid protective barrier around the dispersed droplet. The MOF-stabilized CO2 and water emulsion has exceptional stability compared to those emulsions stabilized by surfactants or other solids. Moreover, the CO2 and water emulsion stabilized by MOF is "tunable" due to the designable features of MOFs and adjustable character of CO2 . Such a novel kind of emulsion composed of CO2 , water, and MOF provides a facile route for constructing MOF superstructures with many advantages. The macroporous networks and hollow capsules of different kinds of MOFs have been successfully derived from CO2 and water emulsions.

Techniques for direct experimental evaluation of structure-transport relationships in disordered porous solids.

Determining structure–transport relationships is critical to optimising the activity and selectivity performance of porous pellets acting as heterogeneous catalysts for diffusion-limited reactions. For amorphous porous systems determining the impact of particular aspects of the void space on mass transport often requires complex characterization and modelling steps to deconvolve the specific influence of the feature in question. These characterization and modelling steps often have limited accuracy and precision. It is the purpose of this work to present a case-study demonstrating the use of a more direct experimental evaluation of the impact of pore network features on mass transport. The case study evaluated the efficacy of the macropores of a bidisperse porous foam structure on improving mass transport over a purely mesoporous system. The method presented involved extending the novel integrated gas sorption and mercury porosimetry method to include uptake kinetics. Results for the new method were compared with those obtained by the alternative NMR cryodiffusometry technique, and found to lead to similar conclusions. It was found that the experimentally-determined degree of influence of the foam macropores was in line with expectations from a simple resistance model for a disconnected macropore network.

Water and solute transport in agricultural soils predicted by volumetric clay and silt contents

Solute transport through the soil matrix is non-uniform and greatly affected by soil texture, soil structure, and macropore networks. Attempts have been made in previous studies to use infiltration experiments to identify the degree of preferential flow, but these attempts have often been based on small datasets or data collected from literature with differing initial and boundary conditions. This study examined the relationship between tracer breakthrough characteristics, soil hydraulic properties, and basic soil properties. From six agricultural fields in Denmark, 193 intact surface soil columns 20cm in height and 20cm in diameter were collected. The soils exhibited a wide range in texture, with clay and organic carbon (OC) contents ranging from 0.03 to 0.41 and 0.01 to 0.08kgkg−1, respectively. All experiments were carried out under the same initial and boundary conditions using tritium as a conservative tracer. The breakthrough characteristics ranged from being near normally distributed to gradually skewed to the right along with an increase in the content of the mineral fines (particles ≤50μm). The results showed that the mineral fines content was strongly correlated to functional soil structure and the derived tracer breakthrough curves (BTCs), whereas the OC content appeared less important for the shape of the BTC. Organic carbon was believed to support the stability of the soil structure rather than the actual formation of macropores causing preferential flow. The arrival times of 5% and up to 50% of the tracer mass were found to be strongly correlated with volumetric fines content. Predicted tracer concentration breakthrough points as a function of time up to 50% of applied tracer mass could be well fitted to an analytical solution to the classical advection-dispersion equation. Both cumulative tracer mass and concentration as a function of time were well predicted from the simple inputs of bulk density, clay and silt contents, and applied tracer mass. The new concept seems promising as a platform towards more accurate proxy functions for dissolved contaminant transport in intact soil.

Novel approach for preparation of poly (ionic liquid) catalyst with macroporous structure for biodiesel production

An efficient poly (ionic liquid) catalyst for biodiesel production was synthesized from Brønsted acidic ionic liquid 1-vinyl-3-(3-sulfopropyl) imidazolium hydrogen sulfate [VSIM][HSO4] through free radical polymerization from a novel approach, where Fe3O4 particles acted as hard template. The template could be easily removed in short time and macrospores formed after the removal of Fe3O4. The structure of the polymer was characterized by different techniques and the results demonstrated that the macroporous polymeric network was multi-layered and exhibited repeating units of SO3H and HSO4 with fine separation efficiency, as a novel heterogeneous acidic catalyst. The catalytic performance of the macroporous polymer was assessed in the esterification reaction of oleic acid for biodiesel production and the Box-Behnken response surface methodology (RSM) was applied for maximizing the biodiesel yield by optimizing process variables at 80°C. Under the optimum conditions (reaction time was 4.5h, catalyst amount was 8.5wt%, and alcohol/acid molar ratio was 12:1), a high biodiesel yield of 92.6% was obtained. The polymeric catalyst also showed favorable reusability after six runs. The combination of macrospores with poly (ionic liquid) would significantly reduce the limitation of mass transfer in biodiesel production compared with other porous solid acidic catalysts.

Connectivity and percolation of structural pore networks in a cultivated silt loam soil quantified by X-ray tomography

The connectivity of macropore networks is thought to exert an important control on preferential flow in soil, although little progress has been made towards incorporating an understanding of these effects into management-oriented flow and transport models. In principle, concepts from percolation theory should be well suited to quantify the connectivity of preferred flow pathways, but so far its relevance for natural soils in the field has not been tested. To investigate this question, X-ray tomography was used to measure soil pore space architecture at an image resolution of 65μm for 64 samples taken in two consecutive years in the harrowed and ploughed layers of a silt loam soil a few weeks after spring cultivation. The results showed that the pore networks displayed key features predicted by classical percolation theory: a strong relationship was found between the percolating fraction and the imaged porosity, with a percolation threshold of ca. 0.04 to 0.06m3m−3 in the harrowed layer. A percolation threshold was less clearly identifiable in topsoil that had not been recently tilled, although this may probably be attributed to finite size sampling effects in this layer, which showed a more heterogeneous and structured distribution of the pore space. Although further work on more strongly structured soil horizons, especially subsoils, would be desirable, it is tentatively suggested that percolation concepts could prove useful to estimate the conducting macroporosity in management models of preferential flow and transport.

Synthesis of Discrete Alkyl‐Silica Hybrid Nanowires and Their Assembly into Nanostructured Superhydrophobic Membranes

AbstractWe report the synthesis of highly flexible and mechanically robust hybrid silica nanowires (NWs) which can be used as novel building blocks to construct superhydrophobic functional materials with three‐dimensional macroporous networks. The hybrid silica NWs, with an average diameter of 80 nm and tunable length of up to 12 μm, are prepared by anisotropic deposition of the hydrolyzed tetraethylorthosilicate in water/n‐pentanol emulsions. A mechanistic investigation reveals that the trimethoxy(octadecyl)silane introduced to the water‐oil interface in the synthesis plays key roles in stabilizing the water droplets to sub‐100 nm and also growing a layer of octadecyl groups on the NW surface. This work opens a solution‐based route for the one‐pot preparation of monodisperse, hydrophobic silica NWs and represents an important step toward the bottom‐up construction of 3D superhydrophobic materials and macroporous membranes.

Synthesis of Discrete Alkyl-Silica Hybrid Nanowires and Their Assembly into Nanostructured Superhydrophobic Membranes.

We report the synthesis of highly flexible and mechanically robust hybrid silica nanowires (NWs) which can be used as novel building blocks to construct superhydrophobic functional materials with three-dimensional macroporous networks. The hybrid silica NWs, with an average diameter of 80 nm and tunable length of up to 12 μm, are prepared by anisotropic deposition of the hydrolyzed tetraethylorthosilicate in water/n-pentanol emulsions. A mechanistic investigation reveals that the trimethoxy(octadecyl)silane introduced to the water-oil interface in the synthesis plays key roles in stabilizing the water droplets to sub-100 nm and also growing a layer of octadecyl groups on the NW surface. This work opens a solution-based route for the one-pot preparation of monodisperse, hydrophobic silica NWs and represents an important step toward the bottom-up construction of 3D superhydrophobic materials and macroporous membranes.

Bilayer Cryogel Wound Dressing and Skin Regeneration Grafts for the Treatment of Acute Skin Wounds.

In this study, the potential of cryogel bilayer wound dressing and skin regenerating graft for the treatment of surgically created full thickness wounds was evaluated. The top layer was composed of polyvinylpyrrolidone-iodine (PVP-I) cryogel and served as the antiseptic layer, while the bottom regenerative layer was made using gelatin cryogel. Both components of the bilayer showed typical features of a cryogel interconnected macropore network, rapid swelling, high water uptake capacity of about 90%. Both PVP and gelatin cryogel showed high tensile strength of 45 and 10 kPa, respectively. Gelatin cryogel sheets were essentially elastic and could be stretched without any visible deformation. The antiseptic PVP-I layer cryogel sheet showed sustained iodine release and suppressed microbial growth when tested with skin pathogens (zone of inhibition ∼2 cm for sheet of 0.9 cm diameter). The gelatin cryogel sheet degraded in vitro in weeks. The gelatin cryogel sheet supported cell infiltration, attachment, and proliferation of fibroblasts and keratinocytes. Microparticles loaded with bioactive molecules (mannose-6-phosphate and human fibrinogen) were also incorporated in the gelatin cryogel sheets for their role in enhancing skin regeneration and scar free wound healing. In vivo evaluation of healing capacity of the bilayer cryogel was checked in rabbits by creating full thickness wound defect (diameter 2 cm). Macroscopic and microscopic observation at regular time intervals for 4 weeks demonstrated better and faster skin regeneration in the wound treated with cryogel bilayer as compared to untreated defect and the repair was comparable to commercial skin regeneration scaffold Neuskin-F. Complete skin regeneration was observed after 4 weeks of implantation with no sign of inflammatory response. Defects implanted with cryogel having mannose-6-phosphate showed no scar formation, while the wound treated with bilayer incorporated with human fibrinogen microparticles showed early signs of skin regeneration; epidermis formation occurred at 2 weeks after implantation.

Quantifying soil macropore networks in different forest communities using industrial computed tomography in a mountainous area of North China

Purpose Macropores have important effects on the movement of soil water, air, and chemical substances. However, the quantitative relationship between complex 3D soil macropore networks and forest communities remains unclear in the northern mountainous area in China. The objectives of this study were to (1) use industrial computed tomography (CT) scanning and image analysis to quantitatively analyze macropore networks in intact soil columns and (2) identify characteristics of soil macropore networks in different forest communities.

Functionally Enhanced Human Stem Cell Derived Hepatocytes in Galactosylated Cellulosic Sponges for Hepatotoxicity Testing.

Pluripotent stem cell derived hepatocyte-like cells (hPSC-HLCs) are an attractive alternative to primary human hepatocytes (PHHs) used in applications ranging from therapeutics to drug safety testing studies. It would be critical to improve and maintain mature hepatocyte functions of the hPSC-HLCs, especially for long-term studies. If 3D culture systems were to be used for such purposes, it would be important that the system can support formation and maintenance of optimal-sized spheroids for long periods of time, and can also be directly deployed in liver drug testing assays. We report the use of 3-dimensional (3D) cellulosic scaffold system for the culture of hPSC-HLCs. The scaffold has a macroporous network which helps to control the formation and maintenance of the spheroids for weeks. Our results show that culturing hPSC-HLCs in 3D cellulosic scaffolds increases functionality, as demonstrated by improved urea production and hepatic marker expression. In addition, hPSC-HLCs in the scaffolds exhibit a more mature phenotype, as shown by enhanced cytochrome P450 activity and induction. This enables the system to show a higher sensitivity to hepatotoxicants and a higher degree of similarity to PHHs when compared to conventional 2D systems. These results suggest that 3D cellulosic scaffolds are ideal for the long-term cultures needed to mature hPSC-HLCs. The mature hPSC-HLCs with improved cellular function can be continually maintained in the scaffolds and directly used for hepatotoxicity assays, making this system highly attractive for drug testing applications.

Strontium-doped organic-inorganic hybrids towards three-dimensional scaffolds for osteogenic cells

Biomimetic organic–inorganic hybrid bioscaffolds are developed to complement or replace damaged fragments in bone tissue surgery. The aim of this work was to develop a simple and fast method to prepare composite material for bone engineering, avoiding time consuming and complex methodologies. The resulting materials (also called in this work as hybrid composites or hybrid scaffolds) have a three-dimensional macroporous polymer-like network derived from triethoxyvinylsilane (TEVS) and 2-hydroxyethylmethacrylate (HEMA) monomers, with incorporated calcium, strontium, and phosphate ions. The materials were fully characterized using FT-IR, biomineralization studies, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy, scratch tests, Young's modulus and compressive strength tests, and gas physisorption. We report a comprehensive study on the in vitro effect of novel strontium doped materials on human bone cells. In vitro investigations were conducted using a normal human osteoblast cell line that mimics the cellular events of the in vivo intramembranous bone formation process. The materials do not have a negative impact on the survival of the normal human osteoblasts; moreover, materials doped with strontium show that not only are cells able to survive, but they also attach to and grow on a bioscaffolds surface. For this reason, they may be used in future in vivo experiments.

Which abiotic filters shape earthworm distribution patterns at the catchment scale?

SummaryEarthworms affect various soil ecosystem processes in their role as ecosystem engineers. The spatial distribution of earthworms determines the spatial distribution of their functional effects. In particular, earthworm‐induced macropore networks may act as preferential flow pathways. In this research we aimed to determine earthworm distributions at the catchment scale with species distribution models (SDMs). We used land‐use types, temporally invariant topography‐related variables and plot‐scale soil characteristics such as pH and organic matter content. We used data from spring 2013 to estimate probability distributions of the occurrence of ten earthworm species. To assess the robustness of these models, we tested temporal transferability by evaluating the accuracy of predictions from the models derived for the spring data with the predictions from data of two other field surveys in autumn 2012 and 2013. In addition, we compared the performance of SDMs based (i) on temporally varying plot‐scale predictor variables with (ii) those based on temporally invariant catchment‐scale predictors. Models based on catchment‐scale predictors, especially land use and slope, experience a small loss of predictive performance only compared with plot‐scale SDMs but have greater temporal transferability. Earthworm distribution maps derived from this kind of SDM are a prerequisite for understanding the spatial distribution patterns of functional effects related to earthworms.Highlights Do plot‐scale variables explain earthworm distributions better than landscape‐scale variables? We modelled ten earthworm species and give comprehensive model evaluations. Landscape‐scale variables are almost as useful as proximate plot‐scale variables. Landscape‐scale variables allow temporally robust mapping, but are limited to the study area.

Synthesis and Textural Characterization of Mesoporous and Meso-/Macroporous Silica Monoliths Obtained by Spinodal Decomposition

Silica monoliths featuring either mesopores or flow-through macropores and mesopores in their skeleton are prepared by combining spinodal phase separation and sol-gel condensation. The macroporous network is first generated by phase separation in acidic medium in the presence of polyethyleneoxides while mesoporosity is engineered in a second step in alkaline medium, possibly in the presence of alkylammonium cations as surfactants. The mesoporous monoliths, also referred as aerogels, are obtained in the presence of alkylpolyethylene oxides in acidic medium without the use of supercritical drying. The impact of the experimental conditions on pore architecture of the monoliths regarding the shape, the ordering, the size and the connectivity of the mesopores is comprehensively discussed based on a critical appraisal of the different models used for textural analysis.

Mn-Containing N-Doped Monolithic Carbon Aerogels with Enhanced Macroporosity as Electrodes for Capacitive Deionization

We propose the use of siliceous diatomite as an antishrinkage additive for the synthesis of monolithic carbon aerogel electrodes with enhanced electrochemical response for capacitive deionization of NaCl solutions. Hybrid N- and Mn-doped carbon aerogels with improved electrical conductivity and wettability in the aqueous electrolyte are prepared by introducing modifications in the synthesis (carbon black and/or diatomite loading before the polymerization sol–gel polycondensation of the monomers, followed by manganese infiltration). The textural and morphological characterizations of the materials reveal that the presence of the additives does not impede the cross-linking of the monomers to form branched clusters and colloidal aggregates leading to a highly porous structure. Furthermore, the aerogel materials display an open macroporous network inherited by the diatomite, even after its lixiviation. As a result, the monolithic carbon aerogel electrodes present good electrochemical performance in terms of l...

Application of X‐ray tomography to quantify macropore characteristics of loess soil under two perennial plants

SummaryWith the advent of large‐scale restoration of vegetation in the Loess Plateau, northwest China, there has been an increase in concern about the suitability of loess soil to support permanent vegetation cover. The quantification of soil macropore characteristics could be critical in determining the architecture and hydrological processes of loess soil on the plateau. In this research, we compared the effects of Purple alfalfa (Medicago sativa L.) and Korshinsk peashrub (Caragana korshinskii K.) on the macropore characteristics of a soil profile on the plateau with computed tomography (CT). To achieve this, undisturbed cores of soil were excavated from beneath purple alfalfa (ALF), 22‐year‐old Korshinsk peashrub (KOP22) and 40‐year‐old Korshinsk peashrub (KOP40) vegetation types in the Liudaogou watershed for evaluation. The soil macropore characteristics (including macroporosity, largest pore area, amounts of macropores, circularity, surface area density, branch density, junction density and connectivity) were determined with image analysis software. Soil under KOP22 and KOP40 treatments had approximately the same amounts of macropores (17 per 6359‐mm2 area), which was three times greater than those under ALF plants. Macroporosity ratios of soil under KOP22 and KOP40 plants to that under ALF plants were 2.3 and 3.6, respectively. Compared with KOP22, KOP40 had a larger macroporosity and the largest pore area at the 100–300‐mm soil depth. The KOP plants, in particular KOP40, apparently improved the macropore network structure of the soil more than ALF. However, the macropores under ALF were much rounder at the 100–300‐mm soil depth than those under the other two plants. There was no correlation between macropore characteristics and organic matter content of the soil at 100–400‐mm depth. Nevertheless, macroporosity was strongly correlated with the largest pore area. The findings of this research are critical for developing strategies for the restoration of vegetation in the Loess Plateau through improvement of the hydrological process of loess soil.Highlights We examined macropore characteristics of loess soil on the Loess Plateau in China. We determined the effects of different plants on soil macropore characteristics. Soil under Korshinsk peashrub had better macropore structure than that under Purple alfalfa. Long‐term recovery of KOP benefits the macropore structure most on the northern Loess Plateau.

Copper indium disulfide nanocrystals supported on carbonized chicken eggshell membranes as efficient counter electrodes for dye-sensitized solar cells

A domestic waste, chicken eggshell membrane (ESM), is used as a raw material to fabricate carbonized ESM loaded with chalcopyrite CuInS2 nanocrystals (denoted CESM-CuInS2) by a simple liquid impregnation and carbonization method. The CESM-CuInS2 composite possesses a natural three-dimensional macroporous network structure in which numerous CuInS2 nanocrystals with a size of about 25 nm are inlaid in carbon submicron fibers that form a microporous network. The CESM-CuInS2 composite is used as the counter electrode in a dye-sensitized solar cell (DSSC) and its photoelectric performance is tested. The DSSC with a CESM-CuInS2 counter electrode exhibits a short-circuit current density of 12.48 mA cm−2, open-circuit voltage of 0.78 V and power conversion efficiency of 5.8%; better than the corresponding values for a DSSC with a CESM counter electrode, and comparable to that of a reference DSSC with a platinum counter electrode. The favorable photoelectric performance of the CESM-CuInS2 counter electrode is attributed to its hierarchical structure, which provides a large specific surface area and numerous catalytically active sites to facilitate the oxidation of the electrolyte. This new composite material has many advantages, such as low cost and simple preparation, compared with Pt and pure CuInS2 counter electrodes.

Preparation of a Binder-Free Three-Dimensional Carbon Foam/Silicon Composite as Potential Material for Lithium Ion Battery Anodes.

We report a novel three-dimensional nitrogen containing carbon foam/silicon (CFS) composite as potential material for lithium ion battery anodes. Carbon foams were prepared by direct carbonization of low cost, commercially available melamine formaldehyde (MF, Basotect) foam precursors. The carbon foams thus obtained display a three-dimensional interconnected macroporous network structure with good electrical conductivity (0.07 S/cm). Binder free CFS composites used for electrodes were prepared by immersing the as-fabricated carbon foam into silicon nanoparticles dispersed in ethanol followed by solvent evaporation and secondary pyrolysis. In order to substantiate this new approach, preliminary electrochemical testing has been done. The first results on CFS electrodes demonstrated initial capacity of 1668 mAh/g with 75% capacity retention after 30 cycles of subsequent charging and discharging. In order to further enhance the electrochemical performance, silicon nanoparticles were additionally coated with a nitrogen containing carbon layer derived from codeposited poly(acrylonitrile). These carbon coated CFS electrodes demonstrated even higher performance with an initial capacity of 2100 mAh/g with 92% capacity retention after 30 cycles of subsequent charging and discharging.

Facile synthesis of graphitic porous carbons with three-dimensional nanonetwork for high-rate supercapacitive energy storage

Meso-/macropore structure and graphite microcrystallite are two critical impacts on high-rate supercapacitive energy storage performance of nanoporous carbon. In the present paper, we prepared a novel graphitic carbon with three-dimensional interconnected meso-/macroporous nanonetwork by a simple one-step Friedel–Crafts crosslinking reaction. A metal-containing aromatic molecule, ferrocene, is selected as started building units. The crosslinking reaction of aromatic rings leads to the formation of meso-/macroporous nanonetworks, and the Fe element can act as a catalyst to accelerate the formation of graphite microcrystallite during carbonization. The experimental results show that the crystal sizes along the c-axis direction (Lc) of the as-obtained graphitic porous carbons are 0.92–1.49 nm and the graphitization do not damage nanopore structure, so that their surface areas are higher than 500 m2 g−1. Owing to their unique structural features, i.e., meso-/macroporous network can shorten the ion transport distance and accelerate ion transport rate, and the moderate graphite microcrystalline is beneficial for electron transfer, this graphitic porous carbon shows high-rate supercapacitive energy storage. For example, the capacitance retention of the as-prepared samples can reach 88 % when the scan rate was raised from 10 to 300 mV s−1.

Nitrogen‐Doped Foam‐like Carbon Plate Consisting of Carbon Tubes as High‐Performance Electrode Materials for Supercapacitors

AbstractA nitrogen‐doped foam‐like 3D carbon plate is prepared by carbonizing a selected biomass precursor of pomelo peel. The carbon plate is composed of interwoven connected carbon tubes and shows a unique 3D interpenetrating macroporous network with binary‐channel structure. Owing to the proper pore structures, short ion‐diffusion paths, high conductivity, and high structure stability, the carbon plate exhibits excellent electrochemical performance as an electrode for supercapacitors directly. A high specific capacitance of up to 338 F g−1 at 1 A g−1, good rate capability with a capacitance retention of 59 % at 20 A g−1, and high cycling stability with only 4 % capacitance loss after 5000 cycles at 20 A g−1 can be achieved in 6 m KOH electrolyte in a three‐electrode system. Furthermore, a symmetric supercapacitor fabricated by using the carbon plates delivers an energy density of 11.05 Wh kg−1 at a power density of 250 W kg−1, and an outstanding cycling stability with only 2.4 % capacitance decay over 5000 cycles at 5 A g−1 in 6 m KOH electrolyte. These very attractive electrochemical properties indicate that the carbon plate derived from pomelo peel is a promising electrode material for supercapacitors.

Electrospun fibrous thin film microextraction coupled with desorption corona beam ionization-mass spectrometry for rapid analysis of antidepressants in human plasma

Appropriate sample preparations prior to analysis can significantly enhance the sensitivity of ambient ionization techniques, especially during the enrichment or purification of analytes in the presence of complex biological matrix. Here in, we developed a rapid analysis method by the combination of thin film microextraction (TFME) and desorption corona beam ionization (DCBI) for the determination of antidepressants in human plasma. Thin films used for extraction consisted of sub-micron sized highly ordered mesoporous silica-carbon composite fibers (OMSCFs), simply prepared by electrospinning and subsequent carbonization. Typically, OMSCFs thin film was immersed into the diluted plasma for extraction of target analytes and then directly subjected to the DCBI-MS for detection. Size-exclusion effect of mesopores contributed to avoid of the protein precipitation step prior to extraction. Mass transfer was benefited from high surface-to-volume ratio which is attributed to macroporous network and ordered mesostructures. Moreover, the OMSCFs provided mixed-mode hydrophobic/ion-exchange interactions towards target analytes. Thus, the detection sensitivity was greatly improved due to effective enrichment of the target analytes and elimination of matrix interferences. After optimization of several parameters related to extraction performance, the proposed method was eventually applied for the determination of three antidepressants in human plasma. The calibration curves were plotted in the range of 5–1000ng/mL with acceptable linearity (R2 >0.983). The limits of detection (S/N=3) of three antidepressants were in ranges of 0.3–1ng/mL. Reproducibility was achieved with RSD less than 17.6% and the relative recoveries were in ranges of 83.6–116.9%. Taken together, TFME–DCBI-MS method offers a powerful capacity for rapid analysis to achieve much-improved sensitivity.