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2022 Volume 50 Issue 3
2022, 50(3): 317-326
doi: 10.19756/j.issn.0253-3820.210810
Abstract:
It is not optimistic about the current situation of global infectious diseases. The diseases are harmful not only to human health, but also to the global public health security. The types of pathogenic microorganisms causing infectious diseases are very complex, and the existing detection technologies cannot effectively give the detection result in a short time and the detection rate is not satisfied. Therefore, it is required to develop a rapid detection technology for infectious diseases. Raman spectroscopy shows great potential in the rapid diagnosis of infectious diseases because it is a non-marker and non-invasive detection technique, without complicated sample pretreatment, and can give the detection result in a short time. This article reviewed the advances of Raman spectroscopy in the rapid diagnosis of bacteria, viruses, fungi, mycoplasma, chlamydia, spirochetes and rickettsia infections.
It is not optimistic about the current situation of global infectious diseases. The diseases are harmful not only to human health, but also to the global public health security. The types of pathogenic microorganisms causing infectious diseases are very complex, and the existing detection technologies cannot effectively give the detection result in a short time and the detection rate is not satisfied. Therefore, it is required to develop a rapid detection technology for infectious diseases. Raman spectroscopy shows great potential in the rapid diagnosis of infectious diseases because it is a non-marker and non-invasive detection technique, without complicated sample pretreatment, and can give the detection result in a short time. This article reviewed the advances of Raman spectroscopy in the rapid diagnosis of bacteria, viruses, fungi, mycoplasma, chlamydia, spirochetes and rickettsia infections.
2022, 50(3): 327-340
doi: 10.19756/j.issn.0253-3820.210811
Abstract:
Due to extensive use and persistent discharge, the environmental levels of antibiotics have been increasing over time. The concentrations of some antibiotics in surface water have reached 300 ng/L, while those in drinking water sources have exceeded 200 ng/L. During disinfection process of drinking water, the antibiotics react with the disinfectants to produce a variety of by-products, some of which are carcinogenic or acutely toxic. These antibiotic disinfection by-products (DBPs) pose direct threat to human health, and thus become the frontier research topic in environmental health science. Based on the studies mostly published in the recent years, this review summarized the analytical methods of DBPs from five major categories of antibiotics (Chloramphenicols, sulfanilamides, fluoroquinolones, tetracyclines, macrolides) including sample pretreatment, chromatography separation and spectroscopic and mass spectrometry detection. Identified DBPs under specific disinfection conditions were then described according to the category of the antibiotics. Furthermore, common toxicity test methods including luminescent bacteria inhibition were introduced, and the test results of some antibiotic DBPs were described. A variety of antibiotic DBPs were identified in previous studies, and some of them were shown to be more toxic than their precursors and thus deserved further investigation.
Due to extensive use and persistent discharge, the environmental levels of antibiotics have been increasing over time. The concentrations of some antibiotics in surface water have reached 300 ng/L, while those in drinking water sources have exceeded 200 ng/L. During disinfection process of drinking water, the antibiotics react with the disinfectants to produce a variety of by-products, some of which are carcinogenic or acutely toxic. These antibiotic disinfection by-products (DBPs) pose direct threat to human health, and thus become the frontier research topic in environmental health science. Based on the studies mostly published in the recent years, this review summarized the analytical methods of DBPs from five major categories of antibiotics (Chloramphenicols, sulfanilamides, fluoroquinolones, tetracyclines, macrolides) including sample pretreatment, chromatography separation and spectroscopic and mass spectrometry detection. Identified DBPs under specific disinfection conditions were then described according to the category of the antibiotics. Furthermore, common toxicity test methods including luminescent bacteria inhibition were introduced, and the test results of some antibiotic DBPs were described. A variety of antibiotic DBPs were identified in previous studies, and some of them were shown to be more toxic than their precursors and thus deserved further investigation.
2022, 50(3): 341-355
doi: 10.19756/j.issn.0253-3820.210768
Abstract:
Hydrogen peroxide (H2O2) is one of the most important reactive oxygen species (ROS) which is related to many physiological and pathological processes in biological systems. Therefore, to understand the important role of hydrogen peroxide in living systems, many fluorescent probes for hydrogen peroxide detection in the biological field have been developed in recent years. Compared with traditional detection methods, fluorescent probes have many advantages such as high sensitivity, non-invasive detection and real-time imaging. In this paper, the research progress of hydrogen peroxide probes in the past five years based on different fluorophores was reviewed, and the challenges and prospect in this field were described.
Hydrogen peroxide (H2O2) is one of the most important reactive oxygen species (ROS) which is related to many physiological and pathological processes in biological systems. Therefore, to understand the important role of hydrogen peroxide in living systems, many fluorescent probes for hydrogen peroxide detection in the biological field have been developed in recent years. Compared with traditional detection methods, fluorescent probes have many advantages such as high sensitivity, non-invasive detection and real-time imaging. In this paper, the research progress of hydrogen peroxide probes in the past five years based on different fluorophores was reviewed, and the challenges and prospect in this field were described.
2022, 50(3): 356-364
doi: 10.19756/j.issn.0253-3820.210582
Abstract:
A two-dimensional porphyrin-based covalent-organic framework (TAPP-TPAL-COF) was prepared by the amine-aldehyde condensation reaction of terephthalaldehyde (TPAL) and 5,10,15,20-tetrakis (4-aminobenzene) porphyrin (TAPP). TAPP-TPAL-COF was porous two-dimensional nanosheets with quadrilateral topological structure and planar conjugated π bonds. The material had π-π conjugate interaction with the glassy carbon electrode, making the material stably immobilized on the surface of the electrode. The porous structure of TAPP-TPAL-COF was conducive to the transmission of mercury ions (Hg2+), and the four N atoms in the porphyrin ring served as Hg2+ coordination sites to enrich Hg2+ in the solution on the electrode surface, improving the sensitivity of the sensor. An Hg2+ electrochemical sensor was thus constructed via TAPP-TPAL-COF. The linear range of the sensor was 10.9 nmol/L-17.5 μmol/L, the limit of detection was 3.3 nmol/L (S/N=3), and the sensitivity was 111.5 μA·L/(μmol·cm2). It took only 250 s to get the current response signals. The sensor presented good stability, high sensitivity, wide linear range, low detection limit and fast response, providing an optional solution for real-time detection of heavy metal ions in water samples.
A two-dimensional porphyrin-based covalent-organic framework (TAPP-TPAL-COF) was prepared by the amine-aldehyde condensation reaction of terephthalaldehyde (TPAL) and 5,10,15,20-tetrakis (4-aminobenzene) porphyrin (TAPP). TAPP-TPAL-COF was porous two-dimensional nanosheets with quadrilateral topological structure and planar conjugated π bonds. The material had π-π conjugate interaction with the glassy carbon electrode, making the material stably immobilized on the surface of the electrode. The porous structure of TAPP-TPAL-COF was conducive to the transmission of mercury ions (Hg2+), and the four N atoms in the porphyrin ring served as Hg2+ coordination sites to enrich Hg2+ in the solution on the electrode surface, improving the sensitivity of the sensor. An Hg2+ electrochemical sensor was thus constructed via TAPP-TPAL-COF. The linear range of the sensor was 10.9 nmol/L-17.5 μmol/L, the limit of detection was 3.3 nmol/L (S/N=3), and the sensitivity was 111.5 μA·L/(μmol·cm2). It took only 250 s to get the current response signals. The sensor presented good stability, high sensitivity, wide linear range, low detection limit and fast response, providing an optional solution for real-time detection of heavy metal ions in water samples.
2022, 50(3): 365-374
doi: 10.19756/j.issn.0253-3820.210873
Abstract:
The electrode-electrolyte interface is very important in electrochemistry, but the quantitative analysis of the adsorption of counter ions on the electrode surface and its influence on the interfacial electric field is extremely lacking, which limits the in-depth understanding of the electrode-electrolyte interface. In this study, four commonly used electrolytes in neutral electrochemical reaction systems were selected, and surface-enhanced infrared absorption spectroelectrochemistry combined with the vibrational Stark effect was used to analyze the special counter-ion effect at the electrode-electrolyte interface. The difference in distributions of anions as counter ions in the electric double layer due to the difference in the strength of the interaction with the electrode surface and the resultant different shielding of the local electric field at the interface were revealed through vibrational Stark probe with different molecular length. Anions that specifically interacted with the electrode could be adsorbed in the Stern layer in large quantities, significantly reducing the local effective electric field. This had far-reaching significance for deep understanding of the electrochemical double layer structure and the structure-activity relationship of the electrocatalytic reaction. At the same time, an effective quantitative analysis method was proposed for analysis of electrode-electrolyte interface.
The electrode-electrolyte interface is very important in electrochemistry, but the quantitative analysis of the adsorption of counter ions on the electrode surface and its influence on the interfacial electric field is extremely lacking, which limits the in-depth understanding of the electrode-electrolyte interface. In this study, four commonly used electrolytes in neutral electrochemical reaction systems were selected, and surface-enhanced infrared absorption spectroelectrochemistry combined with the vibrational Stark effect was used to analyze the special counter-ion effect at the electrode-electrolyte interface. The difference in distributions of anions as counter ions in the electric double layer due to the difference in the strength of the interaction with the electrode surface and the resultant different shielding of the local electric field at the interface were revealed through vibrational Stark probe with different molecular length. Anions that specifically interacted with the electrode could be adsorbed in the Stern layer in large quantities, significantly reducing the local effective electric field. This had far-reaching significance for deep understanding of the electrochemical double layer structure and the structure-activity relationship of the electrocatalytic reaction. At the same time, an effective quantitative analysis method was proposed for analysis of electrode-electrolyte interface.
2022, 50(3): 375-383
doi: 10.19756/j.issn.0253-3820.210847
Abstract:
A highly sensitive and reliable fluorescence sensor for detection of organophosphorus pesticide (OP) based on target-controlled in-situ formation of sadmium sulfide quantum dots (CdS QDs) was developed. Acetylcholinesterase (AChE) catalyzed hydrolysis of acetylthiocholine (ATCh) into thiocholine (TCh), which acted as stabilizing agent to induce the formation of CdS QDs, subsequently improving the emission intensity. Whereas, upon the addition of target methidathion (Met), AChE activity was depressed and thus was not capable of catalyzing hydrolysis of ATCh into TCh. In this context, CdS QDs were not formed and the emission intensity of detection solution was not enhanced, justifying the close relationship between fluorescence signal and Met concentration. Therefore, highly sensitive analysis of Met was achieved on the basis of change in fluorescence emission with a limit of detection of 0.024 ng/mL (S/N=3). Furthermore, the developed fluorescence sensor was successfully employed to detect Met in extract solution of rice with recoveries of 96.7%-102.4%. Overall, the CdS QDs-based sensor presented a new thinking way to highly sensitive and reliable analysis of OPs, favoring OPs-related food safety.
A highly sensitive and reliable fluorescence sensor for detection of organophosphorus pesticide (OP) based on target-controlled in-situ formation of sadmium sulfide quantum dots (CdS QDs) was developed. Acetylcholinesterase (AChE) catalyzed hydrolysis of acetylthiocholine (ATCh) into thiocholine (TCh), which acted as stabilizing agent to induce the formation of CdS QDs, subsequently improving the emission intensity. Whereas, upon the addition of target methidathion (Met), AChE activity was depressed and thus was not capable of catalyzing hydrolysis of ATCh into TCh. In this context, CdS QDs were not formed and the emission intensity of detection solution was not enhanced, justifying the close relationship between fluorescence signal and Met concentration. Therefore, highly sensitive analysis of Met was achieved on the basis of change in fluorescence emission with a limit of detection of 0.024 ng/mL (S/N=3). Furthermore, the developed fluorescence sensor was successfully employed to detect Met in extract solution of rice with recoveries of 96.7%-102.4%. Overall, the CdS QDs-based sensor presented a new thinking way to highly sensitive and reliable analysis of OPs, favoring OPs-related food safety.
2022, 50(3): 384-391
doi: 10.19756/j.issn.0253-3820.210874
Abstract:
Binders play an important role in the commercialization of silicon anodes. Herein, two kinds of commonly used commercial binders, polyvinylidene difluoride (PVDF) and sodium alginate (ALG), were characterized with cyclic charge-discharge test, cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy. The results showed that silicon electrode using binder ALG endowed enhanced cycling stability (200 cycles at 0.1 C) and low-capacity fading rate (0.2% per cycle). In comparison with silicon electrode using binder PVDF, the surface of silicon electrode using ALG was much smoother and exhibited lower impedance after cycling. Furthermore, in-situ electrochemical quartz crystal microbalance (In-situ EQCM) was then introduced to quantitatively record the quality and current changes of electrode in real time, and the generation process of solid electrolyte interface (SEI) film was further analyzed. The analysis results showed that the hydrogen bond interaction between the carboxyl group of binder ALG and the hydroxyl group on silicon electrode could enhance the adhesion of nano-silicon particles to the current collector, promote the formation of a thin and dense SEI film on the electrode surface, reduce the decomposition of electrolyte, and significantly improve the electrochemical performance. In this study, a combination of in-situ and ex-situ characterization was used to make a preliminary discussion on the mechanism of different binders during the charge and discharge process of silicon electrodes.
Binders play an important role in the commercialization of silicon anodes. Herein, two kinds of commonly used commercial binders, polyvinylidene difluoride (PVDF) and sodium alginate (ALG), were characterized with cyclic charge-discharge test, cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy. The results showed that silicon electrode using binder ALG endowed enhanced cycling stability (200 cycles at 0.1 C) and low-capacity fading rate (0.2% per cycle). In comparison with silicon electrode using binder PVDF, the surface of silicon electrode using ALG was much smoother and exhibited lower impedance after cycling. Furthermore, in-situ electrochemical quartz crystal microbalance (In-situ EQCM) was then introduced to quantitatively record the quality and current changes of electrode in real time, and the generation process of solid electrolyte interface (SEI) film was further analyzed. The analysis results showed that the hydrogen bond interaction between the carboxyl group of binder ALG and the hydroxyl group on silicon electrode could enhance the adhesion of nano-silicon particles to the current collector, promote the formation of a thin and dense SEI film on the electrode surface, reduce the decomposition of electrolyte, and significantly improve the electrochemical performance. In this study, a combination of in-situ and ex-situ characterization was used to make a preliminary discussion on the mechanism of different binders during the charge and discharge process of silicon electrodes.
2022, 50(3): 392-404
doi: 10.19756/j.issn.0253-3820.210608
Abstract:
Cobalt oxide, as a transition metal oxide, is widely used in the field of electrochemical sensors and electrocatalysis due to its unique properties. Moreover, metal doping is the main methods to improve the electrochemical performance of electrochemical sensors. In this work, hollow porous SnCoOx nanocubes were prepared by pyrolysis of Sn-doped CoCo-Prussian blue analogues (PBA), and then SnCoOx/graphite felt (GF) composite electrode was prepared by fixing SnCoOx on GF ultrasonically. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), transmission electron microscope (TEM) and electrochemical method were applied to characterize the structure, morphology and electrochemical performance of electrode materials. The composite electrode exhibited excellent electrocatalytic activity for detection of clozapine (CLZ). The electrocatalytic rate constant was kcat=1.04×105L/(mol·s), the linear detection range was 0.01-100 μmol/L, the sensitivity was 6.02 (A·L)/mol, and the limit of detection (LOD, S/N=3) was 0.7 nmol/L. The SnCoOx/GF electrode as an electrochemical sensor for detecting CLZ had perfect anti-interference property, strong stability and practicality, which provided a feasible method for electrochemical detection of CLZ.
Cobalt oxide, as a transition metal oxide, is widely used in the field of electrochemical sensors and electrocatalysis due to its unique properties. Moreover, metal doping is the main methods to improve the electrochemical performance of electrochemical sensors. In this work, hollow porous SnCoOx nanocubes were prepared by pyrolysis of Sn-doped CoCo-Prussian blue analogues (PBA), and then SnCoOx/graphite felt (GF) composite electrode was prepared by fixing SnCoOx on GF ultrasonically. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), transmission electron microscope (TEM) and electrochemical method were applied to characterize the structure, morphology and electrochemical performance of electrode materials. The composite electrode exhibited excellent electrocatalytic activity for detection of clozapine (CLZ). The electrocatalytic rate constant was kcat=1.04×105L/(mol·s), the linear detection range was 0.01-100 μmol/L, the sensitivity was 6.02 (A·L)/mol, and the limit of detection (LOD, S/N=3) was 0.7 nmol/L. The SnCoOx/GF electrode as an electrochemical sensor for detecting CLZ had perfect anti-interference property, strong stability and practicality, which provided a feasible method for electrochemical detection of CLZ.
2022, 50(3): 405-412
doi: 10.19756/j.issn.0253-3820.201749
Abstract:
A split aptamer sensor based on gold nanoparticles (AuNPs) was constructed for detection of adenosine triphosphate (ATP). The ATP aptamer was splited into two fragments (P1 and P2), of which the 5' end of P1 fragment was modified by carboxyfluorescein (FAM) fluorophore, while the P2 fragment with 3' end thiol-functionalization was modified on the AuNPs surface through the self-assembly method by Au-S bond. It was found that the P1 and P2 fragments could not combine together before adding ATP, and the distance between P1 fragments and AuNPs was relatively far, which resulted in strong fluorescence signal. However, after adding ATP into the sensing system, the sandwich structure of P1-ATP-P2 formed, and the FAM fluorophore in the 5' end of P1 fragments approached to the AuNPs, leading to the decrease of the fluorescence intensity due to fluorescence resonance energy transfer effect. Under optimal experimental conditions, the fluorescence intensity of the sensor showed linear relationship with ATP concentration in the range of 0.03-3.33 nmol/L and 3.33-15 nmol/L, respectively, with a detection limit (S/N=3) of 0.03 nmol/L. Furthermore, the constructed sensor had excellent specificity for detection of ATP.
A split aptamer sensor based on gold nanoparticles (AuNPs) was constructed for detection of adenosine triphosphate (ATP). The ATP aptamer was splited into two fragments (P1 and P2), of which the 5' end of P1 fragment was modified by carboxyfluorescein (FAM) fluorophore, while the P2 fragment with 3' end thiol-functionalization was modified on the AuNPs surface through the self-assembly method by Au-S bond. It was found that the P1 and P2 fragments could not combine together before adding ATP, and the distance between P1 fragments and AuNPs was relatively far, which resulted in strong fluorescence signal. However, after adding ATP into the sensing system, the sandwich structure of P1-ATP-P2 formed, and the FAM fluorophore in the 5' end of P1 fragments approached to the AuNPs, leading to the decrease of the fluorescence intensity due to fluorescence resonance energy transfer effect. Under optimal experimental conditions, the fluorescence intensity of the sensor showed linear relationship with ATP concentration in the range of 0.03-3.33 nmol/L and 3.33-15 nmol/L, respectively, with a detection limit (S/N=3) of 0.03 nmol/L. Furthermore, the constructed sensor had excellent specificity for detection of ATP.
2022, 50(3): 413-423
doi: 10.19756/j.issn.0253-3820.211138
Abstract:
In activated carbon/graphite capacitors, electrochemical dilatometry and in-situ X-ray diffraction (XRD) were used to investigate the expansion of graphite negative electrodes during the storage of spiro-(1,1') bipyrrolidinium cation (SBP+) from both macro and micro perspectives. The electrochemical dilatometry can accurately monitor the changes in the macroscopic thickness of the graphite electrode, while in-situ XRD can detect the changes in the microscopic crystal structure of the graphite electrode in real time. Through the comparison of the two set of data, it was found that the relative lattice expansion of graphite caused by ion intercalation on the microscopic scale was very close (56%-59%), with a completely different expansion phenomenon from a macroscopic point of view. Large graphite flakes exhibited a greater expansion (12%), while graphite flakes with a smaller size and spherical graphite demonstrated a very small expansion (5%-6%). The scanning electron microscope test showed that this tendency was closely related to the morphology of graphite and the arrangement of graphite particles on the current collector. The high orientation of large graphite flakes led to the relatively larger electrode expansion, while the disorderly arrangement of thin graphite flakes and the isotropic structure of natural spherical graphite would cause the expansion to be dispersed in all directions, and then made the overall expansion smaller.
In activated carbon/graphite capacitors, electrochemical dilatometry and in-situ X-ray diffraction (XRD) were used to investigate the expansion of graphite negative electrodes during the storage of spiro-(1,1') bipyrrolidinium cation (SBP+) from both macro and micro perspectives. The electrochemical dilatometry can accurately monitor the changes in the macroscopic thickness of the graphite electrode, while in-situ XRD can detect the changes in the microscopic crystal structure of the graphite electrode in real time. Through the comparison of the two set of data, it was found that the relative lattice expansion of graphite caused by ion intercalation on the microscopic scale was very close (56%-59%), with a completely different expansion phenomenon from a macroscopic point of view. Large graphite flakes exhibited a greater expansion (12%), while graphite flakes with a smaller size and spherical graphite demonstrated a very small expansion (5%-6%). The scanning electron microscope test showed that this tendency was closely related to the morphology of graphite and the arrangement of graphite particles on the current collector. The high orientation of large graphite flakes led to the relatively larger electrode expansion, while the disorderly arrangement of thin graphite flakes and the isotropic structure of natural spherical graphite would cause the expansion to be dispersed in all directions, and then made the overall expansion smaller.
2022, 50(3): 424-432
doi: 10.19756/j.issn.0253-3820.221007
Abstract:
Cytomegalovirus (CMV) is very harmful to patients with organ transplantation, pregnant women and newborns. At present,quantitative real-time PCR (qPCR) is the most important method for clinical detection of CMV. However, due to the high cost and complex operation of qPCR, it is difficult to be applied in rapid detection on site. Loop mediated isothermal amplification (LAMP) is a sensitive, simple and rapid nucleic acid detection technology. LAMP shows better amplification efficiency than qPCR, but it is easy to produce dimer between multiple pairs of primers, which will result in nonspecific amplification, and thus cause false positive results. In this study, two probes with complementary sequences were designed to connect magnetic beads (MNs) and silver nanoparticles (AgNPs) modified with Raman probe signal molecule 4-mercaptobenzoic acid (4-MBA). A stronger signal on the surface of AgNPs was obtained by surface enhanced Raman scattering. By using the designed method with the above principle, the standard nucleic acid sequence of CMV was detected, and the detection limit reached 1000 copies/mL. At the level of structural principle of amplification products, the false positive problem perplexing LAMP technology was solved, which showed reference value for the development of new rapid detection technology.
Cytomegalovirus (CMV) is very harmful to patients with organ transplantation, pregnant women and newborns. At present,quantitative real-time PCR (qPCR) is the most important method for clinical detection of CMV. However, due to the high cost and complex operation of qPCR, it is difficult to be applied in rapid detection on site. Loop mediated isothermal amplification (LAMP) is a sensitive, simple and rapid nucleic acid detection technology. LAMP shows better amplification efficiency than qPCR, but it is easy to produce dimer between multiple pairs of primers, which will result in nonspecific amplification, and thus cause false positive results. In this study, two probes with complementary sequences were designed to connect magnetic beads (MNs) and silver nanoparticles (AgNPs) modified with Raman probe signal molecule 4-mercaptobenzoic acid (4-MBA). A stronger signal on the surface of AgNPs was obtained by surface enhanced Raman scattering. By using the designed method with the above principle, the standard nucleic acid sequence of CMV was detected, and the detection limit reached 1000 copies/mL. At the level of structural principle of amplification products, the false positive problem perplexing LAMP technology was solved, which showed reference value for the development of new rapid detection technology.
2022, 50(3): 433-444
doi: 10.19756/j.issn.0253-3820.210787
Abstract:
Based on the dehydration condensation reaction between 2,3-pyridinedicarboxylic acid and 6-amino-β-cyclodextrin, a pyridinediamide bridged bis(β-cyclodextrin) was synthesized and then bonded onto silica gel to obtain a novel pyridinediamide bridged bis(β-cyclodextrin) chiral stationary phase (PyCDP). A total of 38 chiral drugs and pesticides including flavanones, triazoles, amino acids and β-blockers were used as chiral probes to systematically evaluate the chiral high performance liquid chromatography (HPLC) performance of the new stationary phase. Additionally, a common native cyclodextrin stationary phase (CDCSP) was also prepared by the similar method for comparsion purpose. The research results showed that the new bridged cyclodextrin stationary phase could resolve all 38 chiral analytes in both reversed-phase and polar organic modes. Among them, the enantiomeric resolution (Rs) of 2'-hydroxyflavanone, flutriafol, phenylalanine and esmolol were 2.36, 1.98, 1.86 and 1.62 within 30 min, respectively. In reversed-phase chromatographic mode, PyCDP could realize the baseline separations of triazole pesticides by adjusting the volume fraction of acetonitrile (20%-35%) in the mobile phase in the temperature range of 15-30℃, and could resolve triadimenol and bitertanol with two chiral centers into four peaks, respectively. PyCDP achieved the complete separations of easily ionized acidic, basic and polar amino acids in the pH range (5.0-6.5) of the mobile phases. In addition, PyCDP was also suitable for polar organic mode. For example, carvedilol (Rs=1.42) with larger steric hindrance could also be resolved, and it was the first time to realize the separation of bevanolol on cyclodextrin stationary phases. However, under the optimized conditions, CDCSP could only resolve 20 chiral substances with lower resolutions. Obviously, the synergistic inclusion of two adjacent cavities on bridged cyclodextrin and the hydrogen bond and π-π effect provided by pyridinediamide bridging group were conducive to chiral separations. PyCDP was a kind of multifunctional chiral separation materials.
Based on the dehydration condensation reaction between 2,3-pyridinedicarboxylic acid and 6-amino-β-cyclodextrin, a pyridinediamide bridged bis(β-cyclodextrin) was synthesized and then bonded onto silica gel to obtain a novel pyridinediamide bridged bis(β-cyclodextrin) chiral stationary phase (PyCDP). A total of 38 chiral drugs and pesticides including flavanones, triazoles, amino acids and β-blockers were used as chiral probes to systematically evaluate the chiral high performance liquid chromatography (HPLC) performance of the new stationary phase. Additionally, a common native cyclodextrin stationary phase (CDCSP) was also prepared by the similar method for comparsion purpose. The research results showed that the new bridged cyclodextrin stationary phase could resolve all 38 chiral analytes in both reversed-phase and polar organic modes. Among them, the enantiomeric resolution (Rs) of 2'-hydroxyflavanone, flutriafol, phenylalanine and esmolol were 2.36, 1.98, 1.86 and 1.62 within 30 min, respectively. In reversed-phase chromatographic mode, PyCDP could realize the baseline separations of triazole pesticides by adjusting the volume fraction of acetonitrile (20%-35%) in the mobile phase in the temperature range of 15-30℃, and could resolve triadimenol and bitertanol with two chiral centers into four peaks, respectively. PyCDP achieved the complete separations of easily ionized acidic, basic and polar amino acids in the pH range (5.0-6.5) of the mobile phases. In addition, PyCDP was also suitable for polar organic mode. For example, carvedilol (Rs=1.42) with larger steric hindrance could also be resolved, and it was the first time to realize the separation of bevanolol on cyclodextrin stationary phases. However, under the optimized conditions, CDCSP could only resolve 20 chiral substances with lower resolutions. Obviously, the synergistic inclusion of two adjacent cavities on bridged cyclodextrin and the hydrogen bond and π-π effect provided by pyridinediamide bridging group were conducive to chiral separations. PyCDP was a kind of multifunctional chiral separation materials.
2022, 50(3): 445-453
doi: 10.19756/j.issn.0253-3820.210828
Abstract:
Human exhaled breath contains a large number of volatile metabolites relating to human behavior and health states. In this study, solid phase microextraction (SPME) fibers were directly inserted into a facemask (SPME-in-facemask) to form a new facemask microextraction device for extracting human exhaled volatile organic compounds (VOCs). After sampling, SPME fibers were then coupled with different gas chromatography-mass spectrometers (GC-MS) for further identification of extracted VOCs, including conventional GC-MS, portable GC-MS and comprehensive two-dimensional GC-MS. Different SPME fibers and sampling time were investigated and compared. By comparing the background signals of face mask human exhaled VOCs, the effects of food intake and oral care on the compositions and changes of human exhaled VOCs were explored. The detectability and persistence of exhaled exogenous VOCs were investigated. The results showed that the facemask microextraction sampling coupled with GC-MS could be an efficient analytical tool for detecting a large amount of exhaled endogenous and exogenous VOCs. With the unique features of the facemask microextraction device, including safety, simplicity, convenient sampling, and strong adaptability to couple with different GC-MS methods in which portable GC-MS could provide a fast screening within minutes, while GC×GC-MS could give a comprehensive analysis for biomarker discovery. This work presented a novel promising strategy for investigating human health and oral diseases.
Human exhaled breath contains a large number of volatile metabolites relating to human behavior and health states. In this study, solid phase microextraction (SPME) fibers were directly inserted into a facemask (SPME-in-facemask) to form a new facemask microextraction device for extracting human exhaled volatile organic compounds (VOCs). After sampling, SPME fibers were then coupled with different gas chromatography-mass spectrometers (GC-MS) for further identification of extracted VOCs, including conventional GC-MS, portable GC-MS and comprehensive two-dimensional GC-MS. Different SPME fibers and sampling time were investigated and compared. By comparing the background signals of face mask human exhaled VOCs, the effects of food intake and oral care on the compositions and changes of human exhaled VOCs were explored. The detectability and persistence of exhaled exogenous VOCs were investigated. The results showed that the facemask microextraction sampling coupled with GC-MS could be an efficient analytical tool for detecting a large amount of exhaled endogenous and exogenous VOCs. With the unique features of the facemask microextraction device, including safety, simplicity, convenient sampling, and strong adaptability to couple with different GC-MS methods in which portable GC-MS could provide a fast screening within minutes, while GC×GC-MS could give a comprehensive analysis for biomarker discovery. This work presented a novel promising strategy for investigating human health and oral diseases.
2022, 50(3): 454-464
doi: 10.19756/j.issn.0253-3820.210674
Abstract:
The matrix interference has been regarded as the key and difficult point in fire debris analysis. Based on our previous research on styrene-butadiene rubber, a typical matrix involving ‘alkylbenzene’ in molecular structure was correlated with the interference and molecular structure. To further explore the functional group of the matrix interfering with the ignited liquid residues (ILRs) identification, four diene rubber pads, i.e., styrene-butadiene rubber pad, natural rubber pad, butyl rubber pad and ethylene propylene diene monomer rubber pad, were selected in the study. With gas chromatography-mass spectrometry (GC-MS) analysis, the characteristic compounds analysis was made on fire debris of gasoline, rubber pads, and rubber pads after addition of gasoline. The results showed that almost all the target compounds used for gasoline identification could be detected in fire debris of all the diene rubber pad samples, including alkylbenzenes, homologs of indenes, condensed aromatic hydrocarbons, and polycyclic aromatic hydrocarbons, which indicated that the diene rubbers caused remarkable interference to gasoline identification, and overreliance on the presence of target compounds would lead to misidentifications in the presence of diene rubber residues. When 0.5 mL of gasoline was added to 5 g rubber pads, the chromatographs of the fire debris were relatively similar to that of gasoline, suggesting that the existence of diene rubber did not have a false negative effect on gasoline identification. The research results effectively verified once again that the interference extent of matrixes in fire scene was correlated with its chemical composition, which could provide a new idea for understanding the matrix interference to ILRs and predicting the interference extent from the viewpoint of chemical structure.
The matrix interference has been regarded as the key and difficult point in fire debris analysis. Based on our previous research on styrene-butadiene rubber, a typical matrix involving ‘alkylbenzene’ in molecular structure was correlated with the interference and molecular structure. To further explore the functional group of the matrix interfering with the ignited liquid residues (ILRs) identification, four diene rubber pads, i.e., styrene-butadiene rubber pad, natural rubber pad, butyl rubber pad and ethylene propylene diene monomer rubber pad, were selected in the study. With gas chromatography-mass spectrometry (GC-MS) analysis, the characteristic compounds analysis was made on fire debris of gasoline, rubber pads, and rubber pads after addition of gasoline. The results showed that almost all the target compounds used for gasoline identification could be detected in fire debris of all the diene rubber pad samples, including alkylbenzenes, homologs of indenes, condensed aromatic hydrocarbons, and polycyclic aromatic hydrocarbons, which indicated that the diene rubbers caused remarkable interference to gasoline identification, and overreliance on the presence of target compounds would lead to misidentifications in the presence of diene rubber residues. When 0.5 mL of gasoline was added to 5 g rubber pads, the chromatographs of the fire debris were relatively similar to that of gasoline, suggesting that the existence of diene rubber did not have a false negative effect on gasoline identification. The research results effectively verified once again that the interference extent of matrixes in fire scene was correlated with its chemical composition, which could provide a new idea for understanding the matrix interference to ILRs and predicting the interference extent from the viewpoint of chemical structure.
2022, 50(3): 465-471
doi: 10.19756/j.issn.0253-3820.201505
Abstract:
With the increasing emphasis for the pretection of cultural relics, non-destructive or micro-destructive analysis of cultural relics samples is increasingly advocated. At the same time, due to the complexity of cultural relics samples, more stringent and demanding requirements are put forward for the analysis techniques. The pigment analysis and research of painted cultural relics play a pivotal role in the extraction of its cultural relic information, and in the study and elaboration of ancient human history, society, and culture. In this study, a methods for pigment analysis of cultural relics with a very small amount of sampling was proposed, which was applied to the analysis and identification of colored pigments on the surfaces of a painted pottery francium and a painted pottery retort excavated from the Wolhoo Bay Tomb in Yulin. This study used a variety of technical methods such as ultra-depth of field three-dimensional video microscopy system (OM), scanning electron microscope-energy dispersive spectrum (SEM-EDS), micro X-ray diffraction (μ-XRD) and micro laser Raman spectroscopy (MLRM), etc. The comprehensive results showed that the white pigment was bone white (Ca10[PO4]6[OH]2), the red pigment was cinnabar (HgS), and the green pigment was a mixture of malachite (Cu2[OH]2CO3) and gypsum (CaSO4). The purple pigment was Chinese purple (BaCuSi2O6). The method was applied to the analysis of painted cultural relics with very small amount of sampling and reliable analytical results were obtained. This study provided a reference for the analysis of similar heritage samples, and also guided the sampling workers to collect the minimum amount of samples to avoid the "protective damage" to a greater extent.
With the increasing emphasis for the pretection of cultural relics, non-destructive or micro-destructive analysis of cultural relics samples is increasingly advocated. At the same time, due to the complexity of cultural relics samples, more stringent and demanding requirements are put forward for the analysis techniques. The pigment analysis and research of painted cultural relics play a pivotal role in the extraction of its cultural relic information, and in the study and elaboration of ancient human history, society, and culture. In this study, a methods for pigment analysis of cultural relics with a very small amount of sampling was proposed, which was applied to the analysis and identification of colored pigments on the surfaces of a painted pottery francium and a painted pottery retort excavated from the Wolhoo Bay Tomb in Yulin. This study used a variety of technical methods such as ultra-depth of field three-dimensional video microscopy system (OM), scanning electron microscope-energy dispersive spectrum (SEM-EDS), micro X-ray diffraction (μ-XRD) and micro laser Raman spectroscopy (MLRM), etc. The comprehensive results showed that the white pigment was bone white (Ca10[PO4]6[OH]2), the red pigment was cinnabar (HgS), and the green pigment was a mixture of malachite (Cu2[OH]2CO3) and gypsum (CaSO4). The purple pigment was Chinese purple (BaCuSi2O6). The method was applied to the analysis of painted cultural relics with very small amount of sampling and reliable analytical results were obtained. This study provided a reference for the analysis of similar heritage samples, and also guided the sampling workers to collect the minimum amount of samples to avoid the "protective damage" to a greater extent.
2022, 50(3): 472-481
doi: 10.19756/j.issn.0253-3820.210844
Abstract:
A uniform and stable ferroferric oxide supported graphitized carbon black magnetic nanomaterial (GCB/Fe3O4) was prepared by crystal formation method. The crystal structure, surface morphology and magnetic properties of GCB/Fe3O4 were investigated by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and vibrating magnetometer. The adsorption properties of GCB/Fe3O4 for pigment, polyphenol and other interfering substances were studied by taking catechin, curcumin, quercetin, chlorophyllin and β-carotene as objects. The results showed that the magnetic nanomaterials GCB/Fe3O4 retained the original adsorption characteristics of GCB successfully and possessed magnetism. The saturated adsorption capacity of catechin, curcumin, quercetin, chlorophyllin and β-carotene were 7.87, 9.19, 5.65, 3.35 and 6.13 mg/g, respectively, which were increased by 187.2%, 28.9%, 55.2%, 52.3% and 4.6%, respectively, in comparison with GCB. GCB/Fe3O4 was used as magnetic adsorbent to purify 405 kinds of pesticide residues in tea. Compared with the current solid phase extraction or QuEChERs, the operation was simpler and faster, and the purification time could be saved by more than 15%. The recoveries of 393 kinds of pesticide residues in tea were 60%-120%, and the relative standard deviations were 2.6%-14.6%. The experimental results showed that the prepared GCB/Fe3O4 had good adsorption properties and good stability, and could be used for sample pretreatment of pesticide residues in tea.
A uniform and stable ferroferric oxide supported graphitized carbon black magnetic nanomaterial (GCB/Fe3O4) was prepared by crystal formation method. The crystal structure, surface morphology and magnetic properties of GCB/Fe3O4 were investigated by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and vibrating magnetometer. The adsorption properties of GCB/Fe3O4 for pigment, polyphenol and other interfering substances were studied by taking catechin, curcumin, quercetin, chlorophyllin and β-carotene as objects. The results showed that the magnetic nanomaterials GCB/Fe3O4 retained the original adsorption characteristics of GCB successfully and possessed magnetism. The saturated adsorption capacity of catechin, curcumin, quercetin, chlorophyllin and β-carotene were 7.87, 9.19, 5.65, 3.35 and 6.13 mg/g, respectively, which were increased by 187.2%, 28.9%, 55.2%, 52.3% and 4.6%, respectively, in comparison with GCB. GCB/Fe3O4 was used as magnetic adsorbent to purify 405 kinds of pesticide residues in tea. Compared with the current solid phase extraction or QuEChERs, the operation was simpler and faster, and the purification time could be saved by more than 15%. The recoveries of 393 kinds of pesticide residues in tea were 60%-120%, and the relative standard deviations were 2.6%-14.6%. The experimental results showed that the prepared GCB/Fe3O4 had good adsorption properties and good stability, and could be used for sample pretreatment of pesticide residues in tea.
2022, 50(3): 482-490
doi: 10.19756/j.issn.0253-3820.210794
Abstract:
A method for rapid determination of chlorfenapyr in Bacillus thuringiensis formulations with prohibited additions using attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) combined with partial least squares (PLS) analysis was developed. Three Bacillus thuringiensis formulations from different sources were added with different masses of 97.00% (m/m) chlorfenapyr prodrug to prepare 153 mixed samples with chlorfenapyr concentrations ranging from 0.00% to 5.00%. Three pretreatment methods (Savitzky-Golay smoothing (S-G), standard normal variation (SNV) and multivariate scattering correction (MSC)) and five variable selection algorithms (interval partial least-squares (iPLS), moving window partial least-squares (MWPLS), elimination of uninformative variables (UVE), competitive adaptive reweighted sampling (CARS), and the bootstrapping soft shrinkage (BOSS)) were employed to investigate the effects of different pretreatment methods and variable selection methods on the model results. Among them, the MSC pretreatment method combined with the BOSS algorithm obtained the optimal model results, and with this method, RMSECV=0.0017, Rcv2=0.9859, RMSEP=0.0016, and Rpre2=0.9868. For samples with chlorfenapyr concentration ranging from 0.50% to 5.00%, the average relative error of external test sample prediction was 0.0540, and the variables selected by the BOSS algorithm were mainly concentrated in the absorption region of the characteristic peak of chlorfenapyr. This method not only had excellent modeling effect, but also showed good chemical interpretability, and could be applied to the rapid detection of chlorfenapyr in Bacillus thuringiensis formulations with prohibited additions.
A method for rapid determination of chlorfenapyr in Bacillus thuringiensis formulations with prohibited additions using attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) combined with partial least squares (PLS) analysis was developed. Three Bacillus thuringiensis formulations from different sources were added with different masses of 97.00% (m/m) chlorfenapyr prodrug to prepare 153 mixed samples with chlorfenapyr concentrations ranging from 0.00% to 5.00%. Three pretreatment methods (Savitzky-Golay smoothing (S-G), standard normal variation (SNV) and multivariate scattering correction (MSC)) and five variable selection algorithms (interval partial least-squares (iPLS), moving window partial least-squares (MWPLS), elimination of uninformative variables (UVE), competitive adaptive reweighted sampling (CARS), and the bootstrapping soft shrinkage (BOSS)) were employed to investigate the effects of different pretreatment methods and variable selection methods on the model results. Among them, the MSC pretreatment method combined with the BOSS algorithm obtained the optimal model results, and with this method, RMSECV=0.0017, Rcv2=0.9859, RMSEP=0.0016, and Rpre2=0.9868. For samples with chlorfenapyr concentration ranging from 0.50% to 5.00%, the average relative error of external test sample prediction was 0.0540, and the variables selected by the BOSS algorithm were mainly concentrated in the absorption region of the characteristic peak of chlorfenapyr. This method not only had excellent modeling effect, but also showed good chemical interpretability, and could be applied to the rapid detection of chlorfenapyr in Bacillus thuringiensis formulations with prohibited additions.
2022, 50(3): 491-493
doi: 10.19756/j.issn.0253-3820.181080
Abstract:
