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2019 Volume 47 Issue 11
2019, 47(11): 1711-1720
doi: 10.19756/j.issn.0253-3820.191423
Abstract:
Organ-on-a-chip systems aim to build integrated microsystems to simulate human tissue and organ functions by utilizing the control ability of microfluidic chips to microfluids, cells and their micro-environment, for providing low-cost screening and research models close to in-vivo physiological and pathological conditions for evaluation of effectiveness and biosafety of drugs and vaccines, as well as biomedical research. In this review, the progress of organ-on-a-chip systems based on channels, chambers and membranes are introduced according to their structures and cell culturing modes.
Organ-on-a-chip systems aim to build integrated microsystems to simulate human tissue and organ functions by utilizing the control ability of microfluidic chips to microfluids, cells and their micro-environment, for providing low-cost screening and research models close to in-vivo physiological and pathological conditions for evaluation of effectiveness and biosafety of drugs and vaccines, as well as biomedical research. In this review, the progress of organ-on-a-chip systems based on channels, chambers and membranes are introduced according to their structures and cell culturing modes.
2019, 47(11): 1721-1731
doi: 10.19756/j.issn.0253-3820.191369
Abstract:
Covalent organic frameworks (COFs), which consist of light elements and are linked by covalent bonds, are an emerging class of crystalline porous polymer materials. Recently, COFs have gained growing interest for its low density, large specific surface area, adjustable pore size, easy functionalization, etc. At present, COFs have been widely used in the field of gas storage, catalysis and drug delivery. In this review, we mainly focused on the recent progress of COFs in chromatographic separation, optical sensing and sample pretreatment, and then discussed the development prospects of these fields.
Covalent organic frameworks (COFs), which consist of light elements and are linked by covalent bonds, are an emerging class of crystalline porous polymer materials. Recently, COFs have gained growing interest for its low density, large specific surface area, adjustable pore size, easy functionalization, etc. At present, COFs have been widely used in the field of gas storage, catalysis and drug delivery. In this review, we mainly focused on the recent progress of COFs in chromatographic separation, optical sensing and sample pretreatment, and then discussed the development prospects of these fields.
2019, 47(11): 1732-1741
doi: 10.19756/j.issn.0253-3820.191265
Abstract:
Diabetes mellitus is a metabolic disorder disease characterized by hyperglycemia. Long-term physiological environment of hyperglycemia will aggravate the degree of non-enzymatic glycation proteins. Because the abnormal changes of non-enzymatic process will cause a series of pathological changes, non-enzymatic glycation proteins have attracted researchers' attention. Mass spectrometry is an indispensable and powerful analytical tool for qualitative and quantitative analysis of proteins due to its ultra-high sensitivity, excellent detection limit, and multi-component simultaneous analysis, and has been applied to the identification and qualification of non-enzymatic glycation protein. Herein, the principle of non-enzymatic proteins and the research progress of mass spectrometry in the identification and analysis of glycated plasma proteins and hemoglobin in blood were reviewed, and the development trend of this field was prospected.
Diabetes mellitus is a metabolic disorder disease characterized by hyperglycemia. Long-term physiological environment of hyperglycemia will aggravate the degree of non-enzymatic glycation proteins. Because the abnormal changes of non-enzymatic process will cause a series of pathological changes, non-enzymatic glycation proteins have attracted researchers' attention. Mass spectrometry is an indispensable and powerful analytical tool for qualitative and quantitative analysis of proteins due to its ultra-high sensitivity, excellent detection limit, and multi-component simultaneous analysis, and has been applied to the identification and qualification of non-enzymatic glycation protein. Herein, the principle of non-enzymatic proteins and the research progress of mass spectrometry in the identification and analysis of glycated plasma proteins and hemoglobin in blood were reviewed, and the development trend of this field was prospected.
2019, 47(11): 1742-1750
doi: 10.19756/j.issn.0253-3820.191274
Abstract:
DNA tetrahedral nanomaterials have been widely used in the fields of biosensors, drug delivery, bioimaging and separation analysis because of their high stability, good biocompatibility and easy modification. Through different designs, specific functional molecules can be modified at DNA tetrahedral vertices, DNA tetrahedral cage structures, DNA double helix structures, or DNA tetrahedron arms. The advantages of the materials are well combined with the specific functions of the active molecules. This paper first reviewed the development of DNA nanotechnology, and then introduced four different functional modifications of DNA tetrahedron nanomaterials and their research status.
DNA tetrahedral nanomaterials have been widely used in the fields of biosensors, drug delivery, bioimaging and separation analysis because of their high stability, good biocompatibility and easy modification. Through different designs, specific functional molecules can be modified at DNA tetrahedral vertices, DNA tetrahedral cage structures, DNA double helix structures, or DNA tetrahedron arms. The advantages of the materials are well combined with the specific functions of the active molecules. This paper first reviewed the development of DNA nanotechnology, and then introduced four different functional modifications of DNA tetrahedron nanomaterials and their research status.
2019, 47(11): 1751-1758
doi: 10.19756/j.issn.0253-3820.191288
Abstract:
To simultaneously detect bacteria and viruses in a single test, a PCR-array chip based on solid phase PCR(SP-PCR) was developed. Ultraviolet cross-linking method was used to fix oligonucleotide sequence on the grass to develop a PCR array chip for detection of Crimea-Congo hemorrhagic fever virus (CCHFV), Ebola virus, Bacillus anthracis and Brucella multiplex. Owing to the lack of real sample and consideration of biological safety, the vectors of Bacillus anthracis and Brucella were constructed by genetic engineering. Meanwhile, to simulate the reverse transcription process of CCHFV virus and Ebola virus, virus-like particle (VLP) containing two specific viral fragments was constructed by virus packaging technique. The primer fixation efficiency and solid-phase RT-PCR reaction system were optimized with four positive samples. The results showed that the optimum time of cross-linking was 9 min, the optimum concentration was 100 μmol/L, and the minimum detection limit of the multiplex solid-phase RT-PCR was under 10 copy/μL. This method with high sensitivity and specificity avoided mutual interference among the primers by isolation them on space and improved the detection flux. This PCR-Array chip would be widely employed for the rapid parallel detection of bacteria and viruses.
To simultaneously detect bacteria and viruses in a single test, a PCR-array chip based on solid phase PCR(SP-PCR) was developed. Ultraviolet cross-linking method was used to fix oligonucleotide sequence on the grass to develop a PCR array chip for detection of Crimea-Congo hemorrhagic fever virus (CCHFV), Ebola virus, Bacillus anthracis and Brucella multiplex. Owing to the lack of real sample and consideration of biological safety, the vectors of Bacillus anthracis and Brucella were constructed by genetic engineering. Meanwhile, to simulate the reverse transcription process of CCHFV virus and Ebola virus, virus-like particle (VLP) containing two specific viral fragments was constructed by virus packaging technique. The primer fixation efficiency and solid-phase RT-PCR reaction system were optimized with four positive samples. The results showed that the optimum time of cross-linking was 9 min, the optimum concentration was 100 μmol/L, and the minimum detection limit of the multiplex solid-phase RT-PCR was under 10 copy/μL. This method with high sensitivity and specificity avoided mutual interference among the primers by isolation them on space and improved the detection flux. This PCR-Array chip would be widely employed for the rapid parallel detection of bacteria and viruses.
2019, 47(11): 1759-1766
doi: 10.19756/j.issn.0253-3820.191068
Abstract:
With aldehyde-modified glass slide as solid phase, pesticide competitive antigens as coating antigens, gold nanoparticles as labeling material, anti-pesticide monoclonal antibodies as recognition elements and silver-enhance reagent as signal amplification, an immunochip containing 10 combinations of coating antigens and antibodies against corresponding pesticides was developed, which could be used for simultaneous detection of 10 kinds of pesticide residues in agricultural products, including chlorpyrifos, triazophos, carbofuran, thiazoline, imidacloprid, carbendazim, iprodione, aldicarb, fenpropathrin and chlorothalonil. The limits of detection (IC20) of 10 kinds of pesticides were 1.49-15.72 μg/L under the optimized reaction conditions of immunochip. Moreover, the detection process took only 1.5 h. The chip method was applied to the detection of 10 kinds of pesticide residues in fruits (apples), vegetables (cucumbers) and tea (black tea). The sensitivity of the chip met the national Maximum Residue Limit (MRL) standard of pesticides on corresponding crops. Furthermore, the immunochip assay had high accuracy and precision, with recoveries of pesticides from 82.1% to 120.8%, and intra-day and inter-day coefficient of variation less than 10.4% and 12.1%, respectively. The results from the immunochip assay had good correlation with those from mass spectrometer, with R2 of over 0.9591. This immunochip assay provided technical support for rapid detection of pesticide residues, and had practical significance for guaranteeing the quality and safety of agricultural products.
With aldehyde-modified glass slide as solid phase, pesticide competitive antigens as coating antigens, gold nanoparticles as labeling material, anti-pesticide monoclonal antibodies as recognition elements and silver-enhance reagent as signal amplification, an immunochip containing 10 combinations of coating antigens and antibodies against corresponding pesticides was developed, which could be used for simultaneous detection of 10 kinds of pesticide residues in agricultural products, including chlorpyrifos, triazophos, carbofuran, thiazoline, imidacloprid, carbendazim, iprodione, aldicarb, fenpropathrin and chlorothalonil. The limits of detection (IC20) of 10 kinds of pesticides were 1.49-15.72 μg/L under the optimized reaction conditions of immunochip. Moreover, the detection process took only 1.5 h. The chip method was applied to the detection of 10 kinds of pesticide residues in fruits (apples), vegetables (cucumbers) and tea (black tea). The sensitivity of the chip met the national Maximum Residue Limit (MRL) standard of pesticides on corresponding crops. Furthermore, the immunochip assay had high accuracy and precision, with recoveries of pesticides from 82.1% to 120.8%, and intra-day and inter-day coefficient of variation less than 10.4% and 12.1%, respectively. The results from the immunochip assay had good correlation with those from mass spectrometer, with R2 of over 0.9591. This immunochip assay provided technical support for rapid detection of pesticide residues, and had practical significance for guaranteeing the quality and safety of agricultural products.
2019, 47(11): 1767-1775
doi: 10.19756/j.issn.0253-3820.191237
Abstract:
A highly sensitive biothiols-selective fluorescent probe (MCY-NBD) was developed based on the merocyanine fluorophore of 4-(4-hydroxy styryl)-1-methyl pyridine iodide (MCY) and nitro benzo furazan (NBD) as the biothiols-specific recognition group. Upon reacting with biothiols, the probe showed a strong fluorescence enhancement more than 8-fold and very fast response. Moreover, the fluorescence intensity change of MCY-NBD at 526 nm was found to be linearly proportional to biothiols concentrations in the range of 0.1-4.0 μmol/L with a detection limit of 0.03 μmol/L, indicating that MCY-NBD was highly sensitive to biothiols. Confocal laser scanning microscopic imaging experiment proved that MCY-NBD had excellent biocompatibility and cell membrane permeability with low cytotoxicity, which was desirable for fast detection and visualization of both endogenous and exogenous biothiols in live cells.
A highly sensitive biothiols-selective fluorescent probe (MCY-NBD) was developed based on the merocyanine fluorophore of 4-(4-hydroxy styryl)-1-methyl pyridine iodide (MCY) and nitro benzo furazan (NBD) as the biothiols-specific recognition group. Upon reacting with biothiols, the probe showed a strong fluorescence enhancement more than 8-fold and very fast response. Moreover, the fluorescence intensity change of MCY-NBD at 526 nm was found to be linearly proportional to biothiols concentrations in the range of 0.1-4.0 μmol/L with a detection limit of 0.03 μmol/L, indicating that MCY-NBD was highly sensitive to biothiols. Confocal laser scanning microscopic imaging experiment proved that MCY-NBD had excellent biocompatibility and cell membrane permeability with low cytotoxicity, which was desirable for fast detection and visualization of both endogenous and exogenous biothiols in live cells.
2019, 47(11): 1776-1784
doi: 10.19756/j.issn.0253-3820.191305
Abstract:
Molecularly imprinted carbon microspheres (MIC) were synthesized by one-pot hydrothermal method with perfluorooctane sulfonate (PFOS) as template, camellia oleifera seed shell as carbon precursor and phloroglucinol as additive. The as-prepared PFOS-MIC was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), specific surface area and pore size distribution analyzer (BET), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetry/differential thermal analyzer (TG/DTA). The results of SEM, HRTEM and FT-IR showed that the PFOS-MIC had a particle size of about 1.5 μm, the activated binding sites were formed by a large number of interconnected hydrogen bonds. The adsorption properties of PFOS on PFOS-MIC and the corresponding non-imprinted carbon microspheres (NIC) such as adsorption kinetics, pH effect and adsorption isotherms were investigated. Results showed that the adsorption kinetics of PFOS on both NIC and PFOS-MIC fitted well with the secondary-kinetic model (R2 > 0.994). When the temperature was set at 20℃ and pH=3, the adsorption equilibrium time was 1.5 h and 3.0 h, respectively. The lower pH was positive to the adsorption. The adsorption isotherms data fitted better to the Langmuir model (R2>0.993) than that of Freundlich model, and the maximum adsorption capacity at 20℃ was 2930 and 5380 μg/g for NIC and PFOS-MIC, respectively. Adsorption selectivity results indicated that the PFOS-MIC had good adsorption selectivity for PFOS, even in coexistence with the structure analogue surfactants.
Molecularly imprinted carbon microspheres (MIC) were synthesized by one-pot hydrothermal method with perfluorooctane sulfonate (PFOS) as template, camellia oleifera seed shell as carbon precursor and phloroglucinol as additive. The as-prepared PFOS-MIC was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), specific surface area and pore size distribution analyzer (BET), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetry/differential thermal analyzer (TG/DTA). The results of SEM, HRTEM and FT-IR showed that the PFOS-MIC had a particle size of about 1.5 μm, the activated binding sites were formed by a large number of interconnected hydrogen bonds. The adsorption properties of PFOS on PFOS-MIC and the corresponding non-imprinted carbon microspheres (NIC) such as adsorption kinetics, pH effect and adsorption isotherms were investigated. Results showed that the adsorption kinetics of PFOS on both NIC and PFOS-MIC fitted well with the secondary-kinetic model (R2 > 0.994). When the temperature was set at 20℃ and pH=3, the adsorption equilibrium time was 1.5 h and 3.0 h, respectively. The lower pH was positive to the adsorption. The adsorption isotherms data fitted better to the Langmuir model (R2>0.993) than that of Freundlich model, and the maximum adsorption capacity at 20℃ was 2930 and 5380 μg/g for NIC and PFOS-MIC, respectively. Adsorption selectivity results indicated that the PFOS-MIC had good adsorption selectivity for PFOS, even in coexistence with the structure analogue surfactants.
2019, 47(11): 1785-1793
doi: 10.19756/j.issn.0253-3820.191255
Abstract:
By using potassium persulfate as initiator, acrylate (AA) and acrylamide (AM) as monomers, P(AA-co-AM) hydrogel was prepared by aqueous polymerization. The polymerization conditions were optimized by orthogonal test. The P(AA-co-AM) hydrogel was characterized by SEM and FTIR, and the results indicated that the hydrogel had three-dimensional network structure and the carboxyl and acylamino residues could efficiently interact with methylene blue (MB) and malachite green (MG) to form chelates in aqueous solution. The effects of particle size, temperature, pH value and initial concentration of MB and MG on the adsorption performance were investigated. The adsorption isotherm and kinetic behavior of MB and MG on P(AA-co-AM) hydrogel were discussed. The results showed that the decrease of the particle size of the P(AA-co-AM) hydrogel, and the increase of pH value of heavy metal ions solution and adsorption temperature could be in favor of the adsorption of MG on P(AA-co-AM) hydrogel, whereas the lower adsorption temperature could positively influence the adsorption of MB. The adsorption kinetic followed the pseudo-second-order kinetic mode (R2>0.990) and the intra-particle diffusion mode (R3>0.804). The adsorption process was chemisorption. The adsorption isotherm fitted the Freundlich model (RF>0.993), and the adsorption process was multi-molecular layer adsorption. The maximum adsorption amount of MB and MG on P(AA-co-AM) hydrogel were 602.7 and 575.0 mg/g, respectively. Under the optimal desorption conditions, the desorption rates of MB from P(AA-co-AM) hydrogel were 78.18%, 68.35% and 59.34% respectively for repeated three desorption cycles.
By using potassium persulfate as initiator, acrylate (AA) and acrylamide (AM) as monomers, P(AA-co-AM) hydrogel was prepared by aqueous polymerization. The polymerization conditions were optimized by orthogonal test. The P(AA-co-AM) hydrogel was characterized by SEM and FTIR, and the results indicated that the hydrogel had three-dimensional network structure and the carboxyl and acylamino residues could efficiently interact with methylene blue (MB) and malachite green (MG) to form chelates in aqueous solution. The effects of particle size, temperature, pH value and initial concentration of MB and MG on the adsorption performance were investigated. The adsorption isotherm and kinetic behavior of MB and MG on P(AA-co-AM) hydrogel were discussed. The results showed that the decrease of the particle size of the P(AA-co-AM) hydrogel, and the increase of pH value of heavy metal ions solution and adsorption temperature could be in favor of the adsorption of MG on P(AA-co-AM) hydrogel, whereas the lower adsorption temperature could positively influence the adsorption of MB. The adsorption kinetic followed the pseudo-second-order kinetic mode (R2>0.990) and the intra-particle diffusion mode (R3>0.804). The adsorption process was chemisorption. The adsorption isotherm fitted the Freundlich model (RF>0.993), and the adsorption process was multi-molecular layer adsorption. The maximum adsorption amount of MB and MG on P(AA-co-AM) hydrogel were 602.7 and 575.0 mg/g, respectively. Under the optimal desorption conditions, the desorption rates of MB from P(AA-co-AM) hydrogel were 78.18%, 68.35% and 59.34% respectively for repeated three desorption cycles.
2019, 47(11): 1794-1802
doi: 10.19756/j.issn.0253-3820.191457
Abstract:
Utilizing the well-defined topography and uniformly distributed arginine resides on tobacco mosaic virus (TMV) exterior surface, we demonstrated a combined strategy of the biotemplate- and bromide ion induced galvanic replacement method to synthesize one tubular dimension (1D) PdPt alloy. The 1D and tubular structure of TMV/Pd70Pt30NT resulted in the improvement of electrochemically active specific surface area (ECSA) and conductivity. These advantages and PdPt bimetallic electronic effects synergistically led to high electrochemical catalytic activity of TMV/Pd70Pt30NT toward H2O2. The modified screen-printed electrode modified by TMV/Pd70Pt30NT (SPE/TMV/Pd70Pt30NT) had high sensitivity (493 A/(cm2·mol)), which was higher than the SPE modified by Pd nanotube (TMV/PdNT) and commercial Pt/C. Additionally, the electrodes have wide linear detection range of 8.8×10-7-1.0×10-3 mol/L for detection of H2O2, with low detection limit of 2.0×10-7 mol/L(S/N=3).
Utilizing the well-defined topography and uniformly distributed arginine resides on tobacco mosaic virus (TMV) exterior surface, we demonstrated a combined strategy of the biotemplate- and bromide ion induced galvanic replacement method to synthesize one tubular dimension (1D) PdPt alloy. The 1D and tubular structure of TMV/Pd70Pt30NT resulted in the improvement of electrochemically active specific surface area (ECSA) and conductivity. These advantages and PdPt bimetallic electronic effects synergistically led to high electrochemical catalytic activity of TMV/Pd70Pt30NT toward H2O2. The modified screen-printed electrode modified by TMV/Pd70Pt30NT (SPE/TMV/Pd70Pt30NT) had high sensitivity (493 A/(cm2·mol)), which was higher than the SPE modified by Pd nanotube (TMV/PdNT) and commercial Pt/C. Additionally, the electrodes have wide linear detection range of 8.8×10-7-1.0×10-3 mol/L for detection of H2O2, with low detection limit of 2.0×10-7 mol/L(S/N=3).
2019, 47(11): 1803-1808
doi: 10.19756/j.issn.0253-3820.191490
Abstract:
Hydrophilic interaction chromatography (HILIC) coupled with reverse phase liquid chromatography (RPLC) is the most commonly used two-dimensional separation mode. However, it is suffered from the incompatibility of mobile phase. To overcome this issue, a microscale sample transfer technology was developed for capillary HILIC-RPLC two-dimensional liquid chromatography in this work. The sample transfer technology was consisted of weak elution make-up liquid and trap column, so that the strong elution solvent from the first dimension could be diluted effectively. Through optimization of make-up flow rate, the organic concentration of the first dimension effluent was reduced to less than 5%, and up to 95% sample transfer efficiency was achieved. This technology was applied to the two-dimensional separation of five standard protein digest. When 8 sample fractions from the first dimension separation were transferred to the second dimension separation, a theoretical peak capacity of 680 could be obtained. In addition, the peak capacity could be improved with the increasing sampling frequency, suggesting that this technology could be effectively applied to high-resolution separation of complex mixtures.
Hydrophilic interaction chromatography (HILIC) coupled with reverse phase liquid chromatography (RPLC) is the most commonly used two-dimensional separation mode. However, it is suffered from the incompatibility of mobile phase. To overcome this issue, a microscale sample transfer technology was developed for capillary HILIC-RPLC two-dimensional liquid chromatography in this work. The sample transfer technology was consisted of weak elution make-up liquid and trap column, so that the strong elution solvent from the first dimension could be diluted effectively. Through optimization of make-up flow rate, the organic concentration of the first dimension effluent was reduced to less than 5%, and up to 95% sample transfer efficiency was achieved. This technology was applied to the two-dimensional separation of five standard protein digest. When 8 sample fractions from the first dimension separation were transferred to the second dimension separation, a theoretical peak capacity of 680 could be obtained. In addition, the peak capacity could be improved with the increasing sampling frequency, suggesting that this technology could be effectively applied to high-resolution separation of complex mixtures.
2019, 47(11): 1809-1815
doi: 10.19756/j.issn.0253-3820.191206
Abstract:
Lignin can provide fundamental materials for the formation of humus (HS). The process of HS formation can benefit from the microorganisms and their microbial residues. To reveal the contribution of metal (hydro) oxides in promoting the conversion of lignin to HS, a method of liquid flask culture was adopted with lignin as C source. During the process, the fluid medium added with goethite, bayerite and δ-MnO2 respectively was inoculated with the mixed inoculant composed of nine strains. During the culture of 110 d, the mineral-microbial residue was dynamically collected, from which the humic-like acid (HLA) was extracted and analyzed by scanning electron microscope (SEM) and 13C cross-polarization magic-angle-spinning nuclear magnetic resonance spectrum (CPMAS 13C-NMR). The results showed different micro-structures of HLA molecules were formed from the transformation of lignin because of the additions of goethite, bayerite and δ-MnO2. From the perspective of microscopic appearance, the shapes were, respectively:flaky structures in different sizes, irregular spheres with wrinkled edges, and black fungus with uneven surface and irregular wrinkles, among which the HLA particles formed by δ-MnO2 had a tendency to aggregate together. Compared with lignin, the qualities of HLA formed by the participations of three metal (hydro) oxides were improved, and their aliphaticity and hydrophobicity degrees were also enhanced. Compared with humic acid (HA) recommended by the International Humic Substances Society (IHSS), goethite was more likely to promote the hydrophobicity degree of HLA, enhance the protection mechanism to lignin, and stabilize the degree of aliphaticity, while δ-MnO2 had more advantages in improving the quality and hydrophilicity of HLA. Peak positions and their attributions of HLA formed by three metal (hydro) oxides had huge similarity to HA from a soil with straw returning. However, there were some residual components from lignin remained in the HLA molecules. Part of the aromatic C structure in HLA molecules might be replaced by O, N, and the content of carboxylic acid was lower than that of HA recommended by IHSS. Under the participation of δ-MnO2, quinone groups were observed in the HLA molecules, which was a necessary precursor for HS formation. It indicated that δ-MnO2 was superior to goethite and bayerite in promoting lignin humification and could provide precursors for HS formation.
Lignin can provide fundamental materials for the formation of humus (HS). The process of HS formation can benefit from the microorganisms and their microbial residues. To reveal the contribution of metal (hydro) oxides in promoting the conversion of lignin to HS, a method of liquid flask culture was adopted with lignin as C source. During the process, the fluid medium added with goethite, bayerite and δ-MnO2 respectively was inoculated with the mixed inoculant composed of nine strains. During the culture of 110 d, the mineral-microbial residue was dynamically collected, from which the humic-like acid (HLA) was extracted and analyzed by scanning electron microscope (SEM) and 13C cross-polarization magic-angle-spinning nuclear magnetic resonance spectrum (CPMAS 13C-NMR). The results showed different micro-structures of HLA molecules were formed from the transformation of lignin because of the additions of goethite, bayerite and δ-MnO2. From the perspective of microscopic appearance, the shapes were, respectively:flaky structures in different sizes, irregular spheres with wrinkled edges, and black fungus with uneven surface and irregular wrinkles, among which the HLA particles formed by δ-MnO2 had a tendency to aggregate together. Compared with lignin, the qualities of HLA formed by the participations of three metal (hydro) oxides were improved, and their aliphaticity and hydrophobicity degrees were also enhanced. Compared with humic acid (HA) recommended by the International Humic Substances Society (IHSS), goethite was more likely to promote the hydrophobicity degree of HLA, enhance the protection mechanism to lignin, and stabilize the degree of aliphaticity, while δ-MnO2 had more advantages in improving the quality and hydrophilicity of HLA. Peak positions and their attributions of HLA formed by three metal (hydro) oxides had huge similarity to HA from a soil with straw returning. However, there were some residual components from lignin remained in the HLA molecules. Part of the aromatic C structure in HLA molecules might be replaced by O, N, and the content of carboxylic acid was lower than that of HA recommended by IHSS. Under the participation of δ-MnO2, quinone groups were observed in the HLA molecules, which was a necessary precursor for HS formation. It indicated that δ-MnO2 was superior to goethite and bayerite in promoting lignin humification and could provide precursors for HS formation.
2019, 47(11): 1816-1822
doi: 10.19756/j.issn.0253-3820.191363
Abstract:
Zip-Tip C18 solid phase extraction and oxide graphene-lanthanum phosphate nano composite (LaGM) were used to separate saliva peptides respectively. The peptides were identified by high-resolution tandem time-of-flight mass spectrometry (TOF-MS). To reduce accidental errors, the MS analysis repeated once, and the results of two replicates were combined and then were compared at the peptide and protein levels respectively. A total of 545 sequence-specific peptides belonging to 38 proteins were detected by Zip-Tip C18 method, and 359 different peptides coming from 44 proteins were detected by LaGM method, and the two were coincident with 116 peptides (19 proteins). Furthermore, it was found that the peptide distribution characteristics and the dominant peptide composition obtained by the two methods were significantly different. More peptides of Submaxillary gland androgen-regulated protein 3B, Statherin and Salivary acidic proline-rich phosphoprotein 1/2 were enriched by Zip-Tip C18; more peptides of Histatin-1, Hisatin-3 and Protein S100-A8 were detected by LaGM method, and the conclusions were consistent after post-translational modification were included. This study showed that these two methods had a preference for the enrichment of peptides, e.g. the separation process may lead to the loss of some peptides, the possible missing peptides may be the sequence-related peptides, modification-related peptides, protein-related peptides or peptides coming from some other proteins, fortunately, the potential missing peptides were more likely to be related with the peptides that had been detected. This study suggested that it may be not appropriate to use the results of a single separation method to represent the entire peptidome, and although the LaGM method detected fewer peptides, it was more conducive to enrichment of low-abundance peptides, by which more information about degrading proteins could be obtained.
Zip-Tip C18 solid phase extraction and oxide graphene-lanthanum phosphate nano composite (LaGM) were used to separate saliva peptides respectively. The peptides were identified by high-resolution tandem time-of-flight mass spectrometry (TOF-MS). To reduce accidental errors, the MS analysis repeated once, and the results of two replicates were combined and then were compared at the peptide and protein levels respectively. A total of 545 sequence-specific peptides belonging to 38 proteins were detected by Zip-Tip C18 method, and 359 different peptides coming from 44 proteins were detected by LaGM method, and the two were coincident with 116 peptides (19 proteins). Furthermore, it was found that the peptide distribution characteristics and the dominant peptide composition obtained by the two methods were significantly different. More peptides of Submaxillary gland androgen-regulated protein 3B, Statherin and Salivary acidic proline-rich phosphoprotein 1/2 were enriched by Zip-Tip C18; more peptides of Histatin-1, Hisatin-3 and Protein S100-A8 were detected by LaGM method, and the conclusions were consistent after post-translational modification were included. This study showed that these two methods had a preference for the enrichment of peptides, e.g. the separation process may lead to the loss of some peptides, the possible missing peptides may be the sequence-related peptides, modification-related peptides, protein-related peptides or peptides coming from some other proteins, fortunately, the potential missing peptides were more likely to be related with the peptides that had been detected. This study suggested that it may be not appropriate to use the results of a single separation method to represent the entire peptidome, and although the LaGM method detected fewer peptides, it was more conducive to enrichment of low-abundance peptides, by which more information about degrading proteins could be obtained.
2019, 47(11): 1823-1831
doi: 10.19756/j.issn.0253-3820.191361
Abstract:
A Lateral flow assay was developed for the rapid determination of Tebuconazole residues in wheat and vegetables based on the high affinity and specific anti-Tebuconazole monoclonal antibody. For the lateral flow assay development, firstly, 20 nm size colloidal gold nanoparticle was synthesized to label anti-Tebuconazole monoclonal antibody (Mab) as a detection agent. Teb-OVA (0.3 mg/mL) conjugate and goat anti-mouse IgG antibody (1 mg/mL) were coated on nitric acid fiber membrane (NC) to form the test line (T) and quality control line (C), respectively. Under the optimized conditions, the assembled immunochromatographic strip could accomplish the detection of Tebuconazole within 15 min. The Limit of detection observed by naked eyes was 6.25 ng/mL, with negligible cross-reactivity to the analogs of Tebuconazole. Meanwhile, for comparison, a high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established to determine Tebuconazole accurately and quantitatively. The results released that these two developed methods matched each other very well. These two methods could be successfully employed for the detection of Tebuconazole in wheat, cucumber, and cabbage, high-throughput, specific and precise. Immunochromatographic strip could contribute to on-site determination, and LC-MS/MS based method provided accurate quantification.
A Lateral flow assay was developed for the rapid determination of Tebuconazole residues in wheat and vegetables based on the high affinity and specific anti-Tebuconazole monoclonal antibody. For the lateral flow assay development, firstly, 20 nm size colloidal gold nanoparticle was synthesized to label anti-Tebuconazole monoclonal antibody (Mab) as a detection agent. Teb-OVA (0.3 mg/mL) conjugate and goat anti-mouse IgG antibody (1 mg/mL) were coated on nitric acid fiber membrane (NC) to form the test line (T) and quality control line (C), respectively. Under the optimized conditions, the assembled immunochromatographic strip could accomplish the detection of Tebuconazole within 15 min. The Limit of detection observed by naked eyes was 6.25 ng/mL, with negligible cross-reactivity to the analogs of Tebuconazole. Meanwhile, for comparison, a high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established to determine Tebuconazole accurately and quantitatively. The results released that these two developed methods matched each other very well. These two methods could be successfully employed for the detection of Tebuconazole in wheat, cucumber, and cabbage, high-throughput, specific and precise. Immunochromatographic strip could contribute to on-site determination, and LC-MS/MS based method provided accurate quantification.
2019, 47(11): 1832-1841
doi: 10.19756/j.issn.0253-3820.191279
Abstract:
A method for determination of 11 kinds of quinolones residues in blood was developed using supramolecular solvent-based dispersive liquid-liquid microextraction followed by ultra-performance liquid chromatography-hybrid triple quadrupole-linear ion trap mass spectrometry. The supramolecular solvent was prepared with hexanol as extraction solvent and tetrahydrofuran as dispersing agent for dispersive liquid-liquid microextraction of blood samples. The main parameters such as the composition and amount of supramolecular solvent and vortex time were systemically investigated by both single factor and orthogonal experiments in combination with statistical analyses. Chromatographic separation was performed on a Waters ACQUITY UPLC BEH C18 column (50 mm×2.1 mm, 1.7 μm) with mobile phases of acetonitrile and 0.15% aqueous formic acid solution. Data acquisition was carried out in multiple reaction monitoring-information dependent acquisition-enhanced product ion mode for qualitative and quantitative analyses. The 11 kinds of quinolones exhibited good linearity in their respective linear ranges, with correlation coefficients of better than 0.998. The limits of detection and quantitation were in the range of 0.1-0.8 μg/L and 0.4-2.0 μg/L, respectively. The average recoveries at low, medium, and high spiked levels ranged from 70.8% to 115.2% with relative standard deviations of 3.0%-11.5% (n=6).
A method for determination of 11 kinds of quinolones residues in blood was developed using supramolecular solvent-based dispersive liquid-liquid microextraction followed by ultra-performance liquid chromatography-hybrid triple quadrupole-linear ion trap mass spectrometry. The supramolecular solvent was prepared with hexanol as extraction solvent and tetrahydrofuran as dispersing agent for dispersive liquid-liquid microextraction of blood samples. The main parameters such as the composition and amount of supramolecular solvent and vortex time were systemically investigated by both single factor and orthogonal experiments in combination with statistical analyses. Chromatographic separation was performed on a Waters ACQUITY UPLC BEH C18 column (50 mm×2.1 mm, 1.7 μm) with mobile phases of acetonitrile and 0.15% aqueous formic acid solution. Data acquisition was carried out in multiple reaction monitoring-information dependent acquisition-enhanced product ion mode for qualitative and quantitative analyses. The 11 kinds of quinolones exhibited good linearity in their respective linear ranges, with correlation coefficients of better than 0.998. The limits of detection and quantitation were in the range of 0.1-0.8 μg/L and 0.4-2.0 μg/L, respectively. The average recoveries at low, medium, and high spiked levels ranged from 70.8% to 115.2% with relative standard deviations of 3.0%-11.5% (n=6).
2019, 47(11): 1842-1849
doi: 10.19756/j.issn.0253-3820.191276
Abstract:
A solid phase extraction and gas chromatography/mass spectrometry (GC-MS) method was developed for simultaneous extraction and determination of fifteen phthalate esters (PAEs) in black and odorous water. The quantification of 15 kinds of PAEs was performed using a HP-5MS column for chromatographic separation, followed by electren ionization (EI) mass spectra and selected ion monitoring (SIM). Under optimal extraction conditions, 100 mL of water sample at pH 3 was loaded into a WondaSep C18 cartridge, and then eluted with 6 mL of methanol/dichloromethane (1:4, V/V). Satisfactory linearity (R2>0.991) for the target PAEs in matrix of black and odorous water was obtained in the range of 0.05-2 μg/mL, with detection limit of 0.04-0.38 μg/L. The recoveries at two spiked levels (2 and 10 μg/L) in the matrix of black and odorous water generally ranged from 70% to 115%, with relative standard deviation of lower than 10%. The developed method was successfully used to detect PAEs in the actual black and odorous water samples, with total concentration and recoveries (spiked at 2 μg/L) ranging from 2.57 μg/L to 13.69 μg/L and 62% to 115%, respectively.
A solid phase extraction and gas chromatography/mass spectrometry (GC-MS) method was developed for simultaneous extraction and determination of fifteen phthalate esters (PAEs) in black and odorous water. The quantification of 15 kinds of PAEs was performed using a HP-5MS column for chromatographic separation, followed by electren ionization (EI) mass spectra and selected ion monitoring (SIM). Under optimal extraction conditions, 100 mL of water sample at pH 3 was loaded into a WondaSep C18 cartridge, and then eluted with 6 mL of methanol/dichloromethane (1:4, V/V). Satisfactory linearity (R2>0.991) for the target PAEs in matrix of black and odorous water was obtained in the range of 0.05-2 μg/mL, with detection limit of 0.04-0.38 μg/L. The recoveries at two spiked levels (2 and 10 μg/L) in the matrix of black and odorous water generally ranged from 70% to 115%, with relative standard deviation of lower than 10%. The developed method was successfully used to detect PAEs in the actual black and odorous water samples, with total concentration and recoveries (spiked at 2 μg/L) ranging from 2.57 μg/L to 13.69 μg/L and 62% to 115%, respectively.
2019, 47(11): 1850-1856
doi: 10.19756/j.issn.0253-3820.191436
Abstract:
In this study, a catalytic reduction-in-tube solid phase microextraction coupled with capillary liquid chromatography (CR-IT-SPME-CLC) system was developed for rapid analysis of dinitropyrene isomers (DNPs). Pt/Al2O3 and ammonium formate were used as catalyst and hydrogen donor respectively, and three DNPs were reduced efficiently by catalytic hydrogenation at 95℃. A solid phase microextraction monolithic column embedded into nanomaterial with uniform distribution of reduced graphene oxide and good permeability, which was prepared using self-made capillary rotating device by optimizing the composition of the pre-polymerization solution. For highly efficient extraction of three dinitropyrene reduction products, desorption solution of solid phase microextraction was optimized, and the extraction efficiency was 80.47%-93.37%. Capillary chromatography column was packed with C18 particles (5 μm) at high chromatographic pump pressure, and a capillary liquid chromatography-laser induced fluorescence detection system was established. Complete separation of three diaminopyrenes was achieved in 10 min by optimizing the chromatographic separation conditions. The proposed method is simple, rapid and sensitive for the analysis of DNP isomers among nitropolycyclic aromatic hydrocarbons.
In this study, a catalytic reduction-in-tube solid phase microextraction coupled with capillary liquid chromatography (CR-IT-SPME-CLC) system was developed for rapid analysis of dinitropyrene isomers (DNPs). Pt/Al2O3 and ammonium formate were used as catalyst and hydrogen donor respectively, and three DNPs were reduced efficiently by catalytic hydrogenation at 95℃. A solid phase microextraction monolithic column embedded into nanomaterial with uniform distribution of reduced graphene oxide and good permeability, which was prepared using self-made capillary rotating device by optimizing the composition of the pre-polymerization solution. For highly efficient extraction of three dinitropyrene reduction products, desorption solution of solid phase microextraction was optimized, and the extraction efficiency was 80.47%-93.37%. Capillary chromatography column was packed with C18 particles (5 μm) at high chromatographic pump pressure, and a capillary liquid chromatography-laser induced fluorescence detection system was established. Complete separation of three diaminopyrenes was achieved in 10 min by optimizing the chromatographic separation conditions. The proposed method is simple, rapid and sensitive for the analysis of DNP isomers among nitropolycyclic aromatic hydrocarbons.
2019, 47(11): 1857-1863
doi: 10.19756/j.issn.0253-3820.191334
Abstract:
A pre-column derivatization method for determination of amino acids in tobacco leaves by ultra-high performance liquid chromatography-electrospray ion tandem mass spectrometry using 4-nitrobenzoyl chloride as derivatization reagent was developed. The sample was extracted by ultrasound-assisted extraction, and then the extracts were rapidly derived with 4-nitrobenzoyl chloride. The derivative reaction was performed in NH4HCO3-NH3·H2O buffer solution at pH 9.0 and room temperature with oscillation assistance for 1 min. To enhance the sensitivity, the parameters of multiple reaction monitoring were also optimized. This method had many advantages including mild reaction condition, simple procedure and short derivatization time. The method showed a good linearity with correlation coefficients of 0.9951-0.9998. The detection limits were 0.56-2.00 μg/L with RSDs of 0.5%-8.0%. This method coupled with multivariate statistical analysis method was successfully employed for determination of amino acids in tobacco leaves from three different geographical origins, showing a good classification results.
A pre-column derivatization method for determination of amino acids in tobacco leaves by ultra-high performance liquid chromatography-electrospray ion tandem mass spectrometry using 4-nitrobenzoyl chloride as derivatization reagent was developed. The sample was extracted by ultrasound-assisted extraction, and then the extracts were rapidly derived with 4-nitrobenzoyl chloride. The derivative reaction was performed in NH4HCO3-NH3·H2O buffer solution at pH 9.0 and room temperature with oscillation assistance for 1 min. To enhance the sensitivity, the parameters of multiple reaction monitoring were also optimized. This method had many advantages including mild reaction condition, simple procedure and short derivatization time. The method showed a good linearity with correlation coefficients of 0.9951-0.9998. The detection limits were 0.56-2.00 μg/L with RSDs of 0.5%-8.0%. This method coupled with multivariate statistical analysis method was successfully employed for determination of amino acids in tobacco leaves from three different geographical origins, showing a good classification results.
2019, 47(11): 1864-1869
doi: 10.19756/j.issn.0253-3820.181796
Abstract:
Non-metallic fluorine as a pollutant has an important impact on human health and ecosystem. Fluorine in contaminated soil and sediment has long-term accumulation effect. Therefore, the determination of fluorine in soil is of great significance. Fluorine is an extra-light element, the excitation efficiency is low, the fluorescence yield is low, and it is easy to be absorbed in the optical path. In this study, to improve the resolution of fluorine determination, PX8 crystal was applied and the ratio of peak to background of PX8 crystal was nearly 2 times higher than that of PX1 crystal. The X-ray intensity of low atomic number element depended on the composition of matrix to a great extent. To reduce the influence of absorption/enhancement effect on fluorine determination, the calibration curve of fluorine was established by 35 soil reference materials only. The line overlap and matrix interference were corrected by empirical coefficients, and the linearity was good (R2=0.978). The limit of determination of a method (LDM) was 50 μg/g. The method was successfully used for detection of fluorine in 28 soil samples. The results showed that the values of fluorine in soil determined by X-fluorescence could meet the error requirement of the analysis.
Non-metallic fluorine as a pollutant has an important impact on human health and ecosystem. Fluorine in contaminated soil and sediment has long-term accumulation effect. Therefore, the determination of fluorine in soil is of great significance. Fluorine is an extra-light element, the excitation efficiency is low, the fluorescence yield is low, and it is easy to be absorbed in the optical path. In this study, to improve the resolution of fluorine determination, PX8 crystal was applied and the ratio of peak to background of PX8 crystal was nearly 2 times higher than that of PX1 crystal. The X-ray intensity of low atomic number element depended on the composition of matrix to a great extent. To reduce the influence of absorption/enhancement effect on fluorine determination, the calibration curve of fluorine was established by 35 soil reference materials only. The line overlap and matrix interference were corrected by empirical coefficients, and the linearity was good (R2=0.978). The limit of determination of a method (LDM) was 50 μg/g. The method was successfully used for detection of fluorine in 28 soil samples. The results showed that the values of fluorine in soil determined by X-fluorescence could meet the error requirement of the analysis.
