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2022 Volume 50 Issue 2
2022, 50(2): 163-172
doi: 10.19756/j.issn.0253-3820.210707
Abstract:
pH value is one of the most important characteristics in many scientific fields. Since the 1980s, the concept of cheap, reliable and compact pH monitoring has evolved. In many chemical productions, accurate and real-time pH detection is needed. Biochemical and biomedical fields also have great demand for pH monitoring of the microenvironment. In this context, hydrogel pH sensor comes into being, which is a new pH monitoring technology combining responsive hydrogel with sensor. Due to its characteristics of miniaturization and intelligence, it can be applied to many fields such as chemical engineering, biomedicine and environmental detection. This paper reviewed the research progress of hydrogel pH sensing technology in recent years, which was mainly divided into optical, mechanical and electromagnetic principles. And several types of hydrogel pH sensors were described. In addition, the main performance parameters, advantages and disadvantages of various types of hydrogel pH sensors were compared. And the applicable pH range, sensitivity and response time of different types of hydrogel pH sensors were emphatically analyzed. Finally, the challenges and future development of hydrogel pH sensing technology were discussed and prospected.
pH value is one of the most important characteristics in many scientific fields. Since the 1980s, the concept of cheap, reliable and compact pH monitoring has evolved. In many chemical productions, accurate and real-time pH detection is needed. Biochemical and biomedical fields also have great demand for pH monitoring of the microenvironment. In this context, hydrogel pH sensor comes into being, which is a new pH monitoring technology combining responsive hydrogel with sensor. Due to its characteristics of miniaturization and intelligence, it can be applied to many fields such as chemical engineering, biomedicine and environmental detection. This paper reviewed the research progress of hydrogel pH sensing technology in recent years, which was mainly divided into optical, mechanical and electromagnetic principles. And several types of hydrogel pH sensors were described. In addition, the main performance parameters, advantages and disadvantages of various types of hydrogel pH sensors were compared. And the applicable pH range, sensitivity and response time of different types of hydrogel pH sensors were emphatically analyzed. Finally, the challenges and future development of hydrogel pH sensing technology were discussed and prospected.
2022, 50(2): 173-182
doi: 10.19756/j.issn.0253-3820.210789
Abstract:
It is significant to develop efficient, rapid and simple methods for antibiotic detection because excess antibiotic residues have become one of the most serious threats to global public health. Molecularly imprinted polymers (MIPs), as artificial chemical receptors, can recognize and bind target molecules with high affinity and selectivity. Electrochemiluminescence (ECL) is a mature and widely used analytical technique. As a new analytical and detection technology, MIP-ECL technique is a very promising method for detection of antibiotic residues due to the advantages such as good selectivity, high sensitivity and low cost. In this review, the latest development of MIP-ECL antibiotic sensors, especially constructed with signal amplification strategies, is briefly introduced. Finally, current challenges and future perspectives for MIP-ECL sensors are discussed and prospected.
It is significant to develop efficient, rapid and simple methods for antibiotic detection because excess antibiotic residues have become one of the most serious threats to global public health. Molecularly imprinted polymers (MIPs), as artificial chemical receptors, can recognize and bind target molecules with high affinity and selectivity. Electrochemiluminescence (ECL) is a mature and widely used analytical technique. As a new analytical and detection technology, MIP-ECL technique is a very promising method for detection of antibiotic residues due to the advantages such as good selectivity, high sensitivity and low cost. In this review, the latest development of MIP-ECL antibiotic sensors, especially constructed with signal amplification strategies, is briefly introduced. Finally, current challenges and future perspectives for MIP-ECL sensors are discussed and prospected.
2022, 50(2): 183-197
doi: 10.19756/j.issn.0253-3820.210617
Abstract:
Lung cancer has the highest morbidity and mortality among malignant tumors worldwide. The cure rate of lung cancer is high for early diagnosis, thus “early diagnosis and early treatment” has become a consensus. Exhaled gas detection has many advantages including non-invasive detection, convenient sampling and friendly to human body. The biomarkers for early lung cancer might be found through measurement of characteristic metabolites in exhaled gas. Therefore, it is expected to be a simple and effective method of early lung cancer screening, which has attracted lots of attentions. This review summarizes the research progress of early lung cancer screening technology based on detection of exhaled volatile organic compounds (VOCs), including the common clinical screening methods for lung cancer, the exhaled gas components and characteristic VOCs of lung cancer, the collection and pretreatment methods for exhaled VOCs, and the detection techniques for characteristic VOCs of lung cancer. The problems of exhaled gas detection in early lung cancer screening and their future research orientations are also discussed.
Lung cancer has the highest morbidity and mortality among malignant tumors worldwide. The cure rate of lung cancer is high for early diagnosis, thus “early diagnosis and early treatment” has become a consensus. Exhaled gas detection has many advantages including non-invasive detection, convenient sampling and friendly to human body. The biomarkers for early lung cancer might be found through measurement of characteristic metabolites in exhaled gas. Therefore, it is expected to be a simple and effective method of early lung cancer screening, which has attracted lots of attentions. This review summarizes the research progress of early lung cancer screening technology based on detection of exhaled volatile organic compounds (VOCs), including the common clinical screening methods for lung cancer, the exhaled gas components and characteristic VOCs of lung cancer, the collection and pretreatment methods for exhaled VOCs, and the detection techniques for characteristic VOCs of lung cancer. The problems of exhaled gas detection in early lung cancer screening and their future research orientations are also discussed.
2022, 50(2): 198-205
doi: 10.19756/j.issn.0253-3820.210442
Abstract:
Electron impact ion source (EI) is a kind of highly efficient ionization source that can be used in vacuum. The ionization efficiency of EI can reach 0.1%, and EI can ionize almost all substances. In recent years, the development of electron impact ion source-ion trap mass spectrometry (EI-ITMS) has made great progress, which makes portable gas chromatograph-mass spectrometer (GC-MS) widely used in the rapid qualitative and quantitative detection of toxic and harmful substances. However, the performance debugging of EI-ITMS instrument is still very complicated. Firstly, the ion transmission efficiency of EI needs to set up a suitable lens voltage. Secondly, EI ionization will produce a large number of fragmented ions. To ensure the best mass range, it is necessary to continuously fine tune the relevant voltage parameters of the ion trap mass analyzer. In this work, a set of mass range optimization debugging program was established on the basis of homemade EI-ITMS devices. The developed EI-ITMS were connected in the axial direction. The gas sample entered the EI source through a 75-μm quartz capillary tube, and then the generated ions were accelerated and focused under the action of the extraction electrode system and flowed to the ion trap. The frontcap voltage of the ion trap was used as the gate to control the entry of ions. The parameters of the EI were optimized, and the motion trajectory and transmission efficiency of the ions under the experimental conditions were simulated using simion software. The established mass range optimization program was helpful to alleviate the mass discrimination effect of ion trap mass analyzer and realized the analysis of small mass fragments produced by EI ionization. Experiments showed that the established program could successfully optimize the detection of acetone fragment ionm /z 43 and perfluorotributylamine fragment ion m /z 414. This work laid a foundation for the introduction of chromatographic analysis.
Electron impact ion source (EI) is a kind of highly efficient ionization source that can be used in vacuum. The ionization efficiency of EI can reach 0.1%, and EI can ionize almost all substances. In recent years, the development of electron impact ion source-ion trap mass spectrometry (EI-ITMS) has made great progress, which makes portable gas chromatograph-mass spectrometer (GC-MS) widely used in the rapid qualitative and quantitative detection of toxic and harmful substances. However, the performance debugging of EI-ITMS instrument is still very complicated. Firstly, the ion transmission efficiency of EI needs to set up a suitable lens voltage. Secondly, EI ionization will produce a large number of fragmented ions. To ensure the best mass range, it is necessary to continuously fine tune the relevant voltage parameters of the ion trap mass analyzer. In this work, a set of mass range optimization debugging program was established on the basis of homemade EI-ITMS devices. The developed EI-ITMS were connected in the axial direction. The gas sample entered the EI source through a 75-μm quartz capillary tube, and then the generated ions were accelerated and focused under the action of the extraction electrode system and flowed to the ion trap. The frontcap voltage of the ion trap was used as the gate to control the entry of ions. The parameters of the EI were optimized, and the motion trajectory and transmission efficiency of the ions under the experimental conditions were simulated using simion software. The established mass range optimization program was helpful to alleviate the mass discrimination effect of ion trap mass analyzer and realized the analysis of small mass fragments produced by EI ionization. Experiments showed that the established program could successfully optimize the detection of acetone fragment ion
2022, 50(2): 206-216
doi: 10.19756/j.issn.0253-3820.210610
Abstract:
A core-shell structured polydopamine (PDA) functionalized LaCo0.21Ni1.59O3 composite (PDA@LaCo0.21Ni1.59O3) was synthesized, which combined the excellent electrocatalytic properties of LaCo0.21Ni1.59O3 and the abundant amino functional groups of PDA. On the basis of this, a novel electrochemical sensing platform for detection of heavy metal ions was constructed by modifying the composite on the glassy carbon electrode (PDA@LaCo0.21Ni1.59O3/GCE). Under optimized conditions, the sensing platform showed wide linear range and low detection limit for Cu2+, Hg2+ and Pb2+ ions (The linear ranges were 0.05－10.0, 0.005－5.0 and 0.5－2.0 μmol/L, and the detection limits were 67.70, 8.68 and 52.0 nmol/L for Cu2+, Hg2+ and Pb2+ ions, respectively). The constructed sensing platform could be used for simultaneous detection of Cu2+, Hg2+ and Pb2+. This method provided a new strategy for the detection of heavy metals in water environment.
A core-shell structured polydopamine (PDA) functionalized LaCo0.21Ni1.59O3 composite (PDA@LaCo0.21Ni1.59O3) was synthesized, which combined the excellent electrocatalytic properties of LaCo0.21Ni1.59O3 and the abundant amino functional groups of PDA. On the basis of this, a novel electrochemical sensing platform for detection of heavy metal ions was constructed by modifying the composite on the glassy carbon electrode (PDA@LaCo0.21Ni1.59O3/GCE). Under optimized conditions, the sensing platform showed wide linear range and low detection limit for Cu2+, Hg2+ and Pb2+ ions (The linear ranges were 0.05－10.0, 0.005－5.0 and 0.5－2.0 μmol/L, and the detection limits were 67.70, 8.68 and 52.0 nmol/L for Cu2+, Hg2+ and Pb2+ ions, respectively). The constructed sensing platform could be used for simultaneous detection of Cu2+, Hg2+ and Pb2+. This method provided a new strategy for the detection of heavy metals in water environment.
2022, 50(2): 217-224
doi: 10.19756/j.issn.0253-3820.210791
Abstract:
An electrochemical method for sensitive and specific detection of ten-eleven translocation 1 (TET1) protein was developed based on TET1 protein catalyzing the oxidation of 5-methylcytosine (5mC) to generate 5-hydroxymethylcytosine (5hmC) and the immunological recognition of 5hmC by anti-5hmC antibody (Ab). The bare gold electrode modified with gold nanoparticles (AuNPs/Au) was employed as the substrate electrode, while the double-stranded DNA (dsDNA, formed from the hybridization reaction between probe DNA and its complementary DNA that contains 5mC base)was self-assembled onto the AuNPs/Au electrode through the formation of Au—S bond between AuNPs and —SH at 3'-end of probe DNA. In the presence of α-ketoglutaric acid and Fe2+, TET1 protein catalyzed the oxidation of 5mC to produce 5hmC, which triggered the immune-recognition reaction, leading to the immobilization of anti-5hmC antibody. Based on the increasing steric hindrance effect, the electron transmission rate on the electrode surface decreased, and the electrochemical resistance increased, resulting in a decreased electrochemical reduction signal in detection buffer solution. On the basis of the relationship between the decreased electrochemical signal and the concentration of TET1 protein, the detection of TET1 protein was realized. Under the optimal conditions, the developed method presented a wide linear range from 0.5 to 10 μg/mL, with a low detection limit of 0.17 μg/mL (3σ). Moreover, the effect of Pb2+ on the activity of TET1 protein was investigated. The results showed that Pb2+ could inhibit the activity of TET1 protein with IC50 value of 41.72 nmol/L. In addition, this method showed many advantages such as simple operation, inexpensive instrument, high detection sensitivity and selectivity. This work not only provided a new method for detection of TET1 protein, but also presented alternative biomarker and evaluation method for the investigation of ecotoxicological effects of environmental pollutants.
An electrochemical method for sensitive and specific detection of ten-eleven translocation 1 (TET1) protein was developed based on TET1 protein catalyzing the oxidation of 5-methylcytosine (5mC) to generate 5-hydroxymethylcytosine (5hmC) and the immunological recognition of 5hmC by anti-5hmC antibody (Ab). The bare gold electrode modified with gold nanoparticles (AuNPs/Au) was employed as the substrate electrode, while the double-stranded DNA (dsDNA, formed from the hybridization reaction between probe DNA and its complementary DNA that contains 5mC base)was self-assembled onto the AuNPs/Au electrode through the formation of Au—S bond between AuNPs and —SH at 3'-end of probe DNA. In the presence of α-ketoglutaric acid and Fe2+, TET1 protein catalyzed the oxidation of 5mC to produce 5hmC, which triggered the immune-recognition reaction, leading to the immobilization of anti-5hmC antibody. Based on the increasing steric hindrance effect, the electron transmission rate on the electrode surface decreased, and the electrochemical resistance increased, resulting in a decreased electrochemical reduction signal in detection buffer solution. On the basis of the relationship between the decreased electrochemical signal and the concentration of TET1 protein, the detection of TET1 protein was realized. Under the optimal conditions, the developed method presented a wide linear range from 0.5 to 10 μg/mL, with a low detection limit of 0.17 μg/mL (3σ). Moreover, the effect of Pb2+ on the activity of TET1 protein was investigated. The results showed that Pb2+ could inhibit the activity of TET1 protein with IC50 value of 41.72 nmol/L. In addition, this method showed many advantages such as simple operation, inexpensive instrument, high detection sensitivity and selectivity. This work not only provided a new method for detection of TET1 protein, but also presented alternative biomarker and evaluation method for the investigation of ecotoxicological effects of environmental pollutants.
2022, 50(2): 225-234
doi: 10.19756/j.issn.0253-3820.210805
Abstract:
Panax notoginseng (Burk.) F. H. Chen is a species of genus Panax, family Araliaceae, and has been widely used as a traditional Chinese medicine for treatment of cardiovascular diseases. Previous studies on the chemical constituents of Panax notoginseng are mainly focused on the roots and leaves parts, but there are few research on the fruits part. Panax notoginseng fruits (PNF) is a mature berry drupe of Panax notoginseng. In the interest of further exploitation and utilization of this precious medicinal plant, developing new medicinal parts of Panax notoginseng and finding new trace active components, the main chemical ingredients of saponins in PNF were rapidly analyzed and identified by ultra high performance liquid chromatography-orbitrap high resolution mass spectrometry (UPLC-Orbitrap HRMS) in this work, based on the accuracy of the relative molecular mass, fragment ions, and retention behavior compared to those of reference substances. A total of 60 kinds of triterpenoid saponins were identified from ethanol extraction of PNF, including 43 kinds of protopanaxadiol saponins, 3 kinds of protopanaxatriol saponins, 12 kinds of C-17 side chain varied saponins, and 2 kinds of oleanolic acid saponins, respectively. Among them, 3 kinds of double malonylginsenosides were first identified from PNF, namely double malonyginsenoside Rc, double malonyginsenoside Rb2 and double malonyginsenoside Rb3. Meanwhile, the fragmentation patterns of different saponin types were analyzed and summarized. The saponins of PNF were comprehensively clarified in this study, which could provide a theoretical basis for the identification of saponins and utilization of non-medicinal parts of PNF.
Panax notoginseng (Burk.) F. H. Chen is a species of genus Panax, family Araliaceae, and has been widely used as a traditional Chinese medicine for treatment of cardiovascular diseases. Previous studies on the chemical constituents of Panax notoginseng are mainly focused on the roots and leaves parts, but there are few research on the fruits part. Panax notoginseng fruits (PNF) is a mature berry drupe of Panax notoginseng. In the interest of further exploitation and utilization of this precious medicinal plant, developing new medicinal parts of Panax notoginseng and finding new trace active components, the main chemical ingredients of saponins in PNF were rapidly analyzed and identified by ultra high performance liquid chromatography-orbitrap high resolution mass spectrometry (UPLC-Orbitrap HRMS) in this work, based on the accuracy of the relative molecular mass, fragment ions, and retention behavior compared to those of reference substances. A total of 60 kinds of triterpenoid saponins were identified from ethanol extraction of PNF, including 43 kinds of protopanaxadiol saponins, 3 kinds of protopanaxatriol saponins, 12 kinds of C-17 side chain varied saponins, and 2 kinds of oleanolic acid saponins, respectively. Among them, 3 kinds of double malonylginsenosides were first identified from PNF, namely double malonyginsenoside Rc, double malonyginsenoside Rb2 and double malonyginsenoside Rb3. Meanwhile, the fragmentation patterns of different saponin types were analyzed and summarized. The saponins of PNF were comprehensively clarified in this study, which could provide a theoretical basis for the identification of saponins and utilization of non-medicinal parts of PNF.
2022, 50(2): 235-243
doi: 10.19756/j.issn.0253-3820.210770
Abstract:
A kind of novel copper nanoclusters (PEI@CuNCs) with sizes of about 2.4 nm was prepared using polyethyleneimine (PEI) as stabilizer and ascorbic acid as reducing agent, which could be used as probe to detect doxorubicin hydrochloride (DOX). The prepared PEI@CuNCs showed good stability and resistance to photobleaching, and their maximal excitation and emission wavelengths were 430 and 518 nm, respectively. The surface functional groups of PEI@CuNCs were characterized by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. DOX could quench the fluorescence of PEI@CuNCs, on the basis of this, a fluorescence method for detection of DOX was established. Under the optimal conditions, in the DOX concentration range of 1-145 μmol/L, a good linear relationship between the concentration of DOX and F/F0 was observed, with a detection limit of 0.032 μmol/L (S/N=3). In the presence of other antibiotics, this method had high selectivity to DOX. The fluorescence quenching of PEI@CuNCs by DOX was attributed to internal filtration effect (IFE). This work showed great prospects for detecting DOX.
A kind of novel copper nanoclusters (PEI@CuNCs) with sizes of about 2.4 nm was prepared using polyethyleneimine (PEI) as stabilizer and ascorbic acid as reducing agent, which could be used as probe to detect doxorubicin hydrochloride (DOX). The prepared PEI@CuNCs showed good stability and resistance to photobleaching, and their maximal excitation and emission wavelengths were 430 and 518 nm, respectively. The surface functional groups of PEI@CuNCs were characterized by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. DOX could quench the fluorescence of PEI@CuNCs, on the basis of this, a fluorescence method for detection of DOX was established. Under the optimal conditions, in the DOX concentration range of 1-145 μmol/L, a good linear relationship between the concentration of DOX and F/F0 was observed, with a detection limit of 0.032 μmol/L (S/N=3). In the presence of other antibiotics, this method had high selectivity to DOX. The fluorescence quenching of PEI@CuNCs by DOX was attributed to internal filtration effect (IFE). This work showed great prospects for detecting DOX.
2022, 50(2): 244-252
doi: 10.19756/j.issn.0253-3820.210671
Abstract:
The dose-effect relationship of tirofiban (a platelet membrane glycoprotein (GP) Ⅱb/Ⅲa receptor antagonist) in inhibiting platelet adhesion and aggregation was qualitatively and quantitatively evaluated using a novel microscopic three-dimensional (3D) imaging technology. The platelet-rich plasma (PRP) of healthy volunteers was firstly treated by 0-50 μg/mL tirofiban, and then added to collagen fibrin and glass surfaces respectively to induce platelet activation and aggregation. The 3D morphological images of platelet adhesion and aggregation under different experimental conditions were observed by laser microscopic 3D imaging technology. The volume and area coverage rate of platelet aggregates, and the number and activated count of adhesion platelet were quantified. The results showed that the 3D micro-morphology of platelet aggregates formed on the surfaces of collagen fibrin and glass could be visually observed by the laser microscopic 3D imaging technology. The platelet aggregates formed on the surface of collagen fibrin were thin, and those on the surface of glass were hill-like. When the final concentration of tirofiban was 1.56-12.5 μg/mL, the volume and area coverage rate of platelet aggregate decreased significantly with the increase of tirofiban final concentration. When the concentration increased to 25 and 50 μg/mL, platelets adhered to collagen fibrin only, and the number of platelet adhesion and the proportion of activated platelets decreased significantly with the increase of concentration. On the glass surface, the tirofiban with concentration of 1.56 μg/mL could reduce the volume and area coverage rate of platelet aggregates; and when the concentration was 3.15-50 μg/mL, it could completely inhibit platelet aggregation, and the number of platelet adhesion and the proportion of activated platelets decreased with the increase of tirofiban concentration. As a result, when the concentration was 3.15-12.5 μg/mL, tirofiban could not only completely inhibit platelet aggregation on the glass surface but retain partial aggregation ability on collagen fibrin surface. The microscopic 3D imaging technique could quantitatively and qualitatively analyze the dose-effect relationship of tirofiban inhibiting platelet adhesion aggregation on collagen fibrin surface and glass surface, which provided a new analytical method for rational clinical selection of tirofiban dose.
The dose-effect relationship of tirofiban (a platelet membrane glycoprotein (GP) Ⅱb/Ⅲa receptor antagonist) in inhibiting platelet adhesion and aggregation was qualitatively and quantitatively evaluated using a novel microscopic three-dimensional (3D) imaging technology. The platelet-rich plasma (PRP) of healthy volunteers was firstly treated by 0-50 μg/mL tirofiban, and then added to collagen fibrin and glass surfaces respectively to induce platelet activation and aggregation. The 3D morphological images of platelet adhesion and aggregation under different experimental conditions were observed by laser microscopic 3D imaging technology. The volume and area coverage rate of platelet aggregates, and the number and activated count of adhesion platelet were quantified. The results showed that the 3D micro-morphology of platelet aggregates formed on the surfaces of collagen fibrin and glass could be visually observed by the laser microscopic 3D imaging technology. The platelet aggregates formed on the surface of collagen fibrin were thin, and those on the surface of glass were hill-like. When the final concentration of tirofiban was 1.56-12.5 μg/mL, the volume and area coverage rate of platelet aggregate decreased significantly with the increase of tirofiban final concentration. When the concentration increased to 25 and 50 μg/mL, platelets adhered to collagen fibrin only, and the number of platelet adhesion and the proportion of activated platelets decreased significantly with the increase of concentration. On the glass surface, the tirofiban with concentration of 1.56 μg/mL could reduce the volume and area coverage rate of platelet aggregates; and when the concentration was 3.15-50 μg/mL, it could completely inhibit platelet aggregation, and the number of platelet adhesion and the proportion of activated platelets decreased with the increase of tirofiban concentration. As a result, when the concentration was 3.15-12.5 μg/mL, tirofiban could not only completely inhibit platelet aggregation on the glass surface but retain partial aggregation ability on collagen fibrin surface. The microscopic 3D imaging technique could quantitatively and qualitatively analyze the dose-effect relationship of tirofiban inhibiting platelet adhesion aggregation on collagen fibrin surface and glass surface, which provided a new analytical method for rational clinical selection of tirofiban dose.
2022, 50(2): 253-262
doi: 10.19756/j.issn.0253-3820.210758
Abstract:
A bismuth oxyiodide-bismuth/short carbon nanotube (BiOI-Bi/s-CNTs) composite was prepared by hybridization of short carbon nanotubes (s-CNTs) with bismuth oxyiodide-bismuth (BiOI-Bi). The morphological analysis by scanning electron microscopy (SEM) showed that the prepared BiOI-Bi/s-CNTs consisted of s-CNTs loaded with nanoparticles and a large number of microspheres.Besides, the transient photocurrent displayed that the BiOI-Bi/s-CNTs had excellent photoelectrochemical performance. Thus, a novel cathodic photoelectrochemical method was developed for detection of chlorpyrifos (CPF) with BiOI-Bi/s-CNTs as photocathode and K3[Fe(CN)6] as photoelectron acceptor on the basis of that CPF chelated on the cathode surface and quenched the photocurrent signal. The CPF concentration in the range of 4.0 pg/mL-10.0 ng/mL was positively correlated with the quenched photocurrent, and the detection limit was estimated to be 1.89 pg/mL. The recoveries of CPF in real cabbage and Chinese cabbage were 90.0%-108.0%. This work provided a more specific and sensitive method for determination of CPF.
A bismuth oxyiodide-bismuth/short carbon nanotube (BiOI-Bi/s-CNTs) composite was prepared by hybridization of short carbon nanotubes (s-CNTs) with bismuth oxyiodide-bismuth (BiOI-Bi). The morphological analysis by scanning electron microscopy (SEM) showed that the prepared BiOI-Bi/s-CNTs consisted of s-CNTs loaded with nanoparticles and a large number of microspheres.Besides, the transient photocurrent displayed that the BiOI-Bi/s-CNTs had excellent photoelectrochemical performance. Thus, a novel cathodic photoelectrochemical method was developed for detection of chlorpyrifos (CPF) with BiOI-Bi/s-CNTs as photocathode and K3[Fe(CN)6] as photoelectron acceptor on the basis of that CPF chelated on the cathode surface and quenched the photocurrent signal. The CPF concentration in the range of 4.0 pg/mL-10.0 ng/mL was positively correlated with the quenched photocurrent, and the detection limit was estimated to be 1.89 pg/mL. The recoveries of CPF in real cabbage and Chinese cabbage were 90.0%-108.0%. This work provided a more specific and sensitive method for determination of CPF.
2022, 50(2): 263-270
doi: 10.19756/j.issn.0253-3820.210554
Abstract:
Specially designed small molecule compounds can covalently bind to the catalytic domain of KRas, thereby inhibiting the effect of downstream effector molecules. In this work, a high-purity KRas protein catalytic domain (AA 1-169) was prepared by nickel column affinity chromatography, enzyme cleavage labeling, gel chromatography and other steps. The results showed that KRas protein bound to the small molecule inhibitor ZCL1688 through K42 residue by isothermal titration calorimetry (ITC) experiments. Next, the modeled structure of the complex of KRas and ZCL1688 was obtained through molecular docking, and it was found that the combination of the two molecules had a significant competitive effect on the binding of KRas to down stream protein, serine/threonine kinase RAF. A simple method for high-efficiency expression and high-purity preparation of the KRas protein catalytic domain (AA 1-169) were thus established. The binding mode and weak interaction between KRas and ZCL1688 were analyzed. It laid a good foundation for the subsequent screening of the binding conditions of the protein with small molecule inhibitors and analysis of complex structure.
Specially designed small molecule compounds can covalently bind to the catalytic domain of KRas, thereby inhibiting the effect of downstream effector molecules. In this work, a high-purity KRas protein catalytic domain (AA 1-169) was prepared by nickel column affinity chromatography, enzyme cleavage labeling, gel chromatography and other steps. The results showed that KRas protein bound to the small molecule inhibitor ZCL1688 through K42 residue by isothermal titration calorimetry (ITC) experiments. Next, the modeled structure of the complex of KRas and ZCL1688 was obtained through molecular docking, and it was found that the combination of the two molecules had a significant competitive effect on the binding of KRas to down stream protein, serine/threonine kinase RAF. A simple method for high-efficiency expression and high-purity preparation of the KRas protein catalytic domain (AA 1-169) were thus established. The binding mode and weak interaction between KRas and ZCL1688 were analyzed. It laid a good foundation for the subsequent screening of the binding conditions of the protein with small molecule inhibitors and analysis of complex structure.
2022, 50(2): 271-277
doi: 10.19756/j.issn.0253-3820.211059
Abstract:
An analytical strategy for simultaneous and rapid screening of 108 kinds of veterinary drug residues in livestock and poultry meat was established by using solid-phase extraction (SPE) to reduce impurity interference in samples and based on ultra-high performance liquid chromatography-quadrupole/orbitrap high resolution mass spectrometry (UHPLC-Q/Orbitrap HRMS). The homogenized samples were extracted by 80% acetonitrile aqueous solution (containing 0.2% formic acid), purified by Oasis PRiME HLB solid phase extraction column, and redissolved by nitrogen blowing. The target analytes were separated from the samples by an Agilent Eclipse plus C18 (3.0 mm×150 mm, 1.8 μm) chromatographic column, with acetonitrile and 0.1% acetic acid-ammonium formate (20 mmol/L) aqueous solution system as the mobile phase in gradient elution. Under the heated electrospray ionization positive and negative ions simultaneous scan mode, the target analytes were analyzed by the full scan of primary mass spectrometry plus data-dependent secondary mass spectrometry (Full MS/dd-MS2), and quantitatively detected by a matrix matching quantitative standard curve method. The results showed that 108 kinds of veterinary drugs had a good linear relationship in the range of 0.5-2000 ng/mL, and the correlation coefficients (R) were over 0.9950. The limits of detection (LODs) were 0.1-20 μg/kg, and the limits of quantitation (LOQs) were 0.2-100 μg/kg. The standard recoveries of different livestock and poultry meat under three levels of addition (n=6) were 68.7%-112.5%, and the relative standard deviation (RSDs) were 0.9%-9.7%. This method was simple, rapid and accurate, with wide coverage and high-throughput, and was suitable for rapid screening and confirmative analysis of veterinary drug residues in livestock and poultry meat.
An analytical strategy for simultaneous and rapid screening of 108 kinds of veterinary drug residues in livestock and poultry meat was established by using solid-phase extraction (SPE) to reduce impurity interference in samples and based on ultra-high performance liquid chromatography-quadrupole/orbitrap high resolution mass spectrometry (UHPLC-Q/Orbitrap HRMS). The homogenized samples were extracted by 80% acetonitrile aqueous solution (containing 0.2% formic acid), purified by Oasis PRiME HLB solid phase extraction column, and redissolved by nitrogen blowing. The target analytes were separated from the samples by an Agilent Eclipse plus C18 (3.0 mm×150 mm, 1.8 μm) chromatographic column, with acetonitrile and 0.1% acetic acid-ammonium formate (20 mmol/L) aqueous solution system as the mobile phase in gradient elution. Under the heated electrospray ionization positive and negative ions simultaneous scan mode, the target analytes were analyzed by the full scan of primary mass spectrometry plus data-dependent secondary mass spectrometry (Full MS/dd-MS2), and quantitatively detected by a matrix matching quantitative standard curve method. The results showed that 108 kinds of veterinary drugs had a good linear relationship in the range of 0.5-2000 ng/mL, and the correlation coefficients (R) were over 0.9950. The limits of detection (LODs) were 0.1-20 μg/kg, and the limits of quantitation (LOQs) were 0.2-100 μg/kg. The standard recoveries of different livestock and poultry meat under three levels of addition (n=6) were 68.7%-112.5%, and the relative standard deviation (RSDs) were 0.9%-9.7%. This method was simple, rapid and accurate, with wide coverage and high-throughput, and was suitable for rapid screening and confirmative analysis of veterinary drug residues in livestock and poultry meat.
2022, 50(2): 278-289
doi: 10.19756/j.issn.0253-3820.210603
Abstract:
Human milk oligosaccharides (HMOs) are closely related to the growth and development of infants in early life. In this study, the structures of 19 HMOs (16 neutral HMOs and 3 sialylated HMOs) were analyzed by ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS). Based on the cleavage rules of oligosaccharide isomers, the differences of fragment ions among the four groups of isomers were discussed. The separation effects of HMOs isomers under three different UHPLC conditions were compared, which provided scientific basis for the structural analysis of complex HMOs isomers and the selection of UHPLC conditions.
Human milk oligosaccharides (HMOs) are closely related to the growth and development of infants in early life. In this study, the structures of 19 HMOs (16 neutral HMOs and 3 sialylated HMOs) were analyzed by ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS). Based on the cleavage rules of oligosaccharide isomers, the differences of fragment ions among the four groups of isomers were discussed. The separation effects of HMOs isomers under three different UHPLC conditions were compared, which provided scientific basis for the structural analysis of complex HMOs isomers and the selection of UHPLC conditions.
2022, 50(2): 290-299
doi: 10.19756/j.issn.0253-3820.211170
Abstract:
A gas chromatography (GC) method was established for determination of conversion rate and product content in the desymmetric enantioselective reduction of 1,3-cyclopentadione compounds. This method could be used as a useful supplementary method to investigate the mechanism of desymmetric enantioselective reduction of cyclic 1,3-diketones catalyzed by chiral phosphonamides. The samples were separated on a DB-WAX column (30 m×0.25 mm, 0.25 μm) and analyzed qualitatively and quantitatively by gas chromatography using a standard compound comparison method. The method could be used for convenient, rapid and accurate determination of content of the remaining starting materials and different products generated at different reaction time. By using the established detection method, the reaction course under four different reaction conditions (without additive and catalyst, with additive only, with catalyst only and with both additive and catalyst) were monitored in detail. The results showed that the reaction with the concomitant presence of N,N-diisopropylethylamine (DIPEA) and catalyst not only proceeded much faster but also provided higher yields compared with other three reaction systems. Namely, the conversion rate was up to 80% within 5 min, and the content of target product was close to 70%. In addition, control experiments showed that the addition of DIPEA could also greatly improve the enantioselectivity of the product. Consequently, a combination of these results with our previous mechanistic study by using NMR method provided a further understanding of the mechanism of the related reactions, namely, the addition of amine additives could promote the formation of chiral catalytically active species.
A gas chromatography (GC) method was established for determination of conversion rate and product content in the desymmetric enantioselective reduction of 1,3-cyclopentadione compounds. This method could be used as a useful supplementary method to investigate the mechanism of desymmetric enantioselective reduction of cyclic 1,3-diketones catalyzed by chiral phosphonamides. The samples were separated on a DB-WAX column (30 m×0.25 mm, 0.25 μm) and analyzed qualitatively and quantitatively by gas chromatography using a standard compound comparison method. The method could be used for convenient, rapid and accurate determination of content of the remaining starting materials and different products generated at different reaction time. By using the established detection method, the reaction course under four different reaction conditions (without additive and catalyst, with additive only, with catalyst only and with both additive and catalyst) were monitored in detail. The results showed that the reaction with the concomitant presence of N,N-diisopropylethylamine (DIPEA) and catalyst not only proceeded much faster but also provided higher yields compared with other three reaction systems. Namely, the conversion rate was up to 80% within 5 min, and the content of target product was close to 70%. In addition, control experiments showed that the addition of DIPEA could also greatly improve the enantioselectivity of the product. Consequently, a combination of these results with our previous mechanistic study by using NMR method provided a further understanding of the mechanism of the related reactions, namely, the addition of amine additives could promote the formation of chiral catalytically active species.
2022, 50(2): 300-309
doi: 10.19756/j.issn.0253-3820.201492
Abstract:
The self-made silica gels functionalized with various multidentate ligands were used as adsorbents to explore the effects of ligand dentate numbers on the adsorption of common heavy metal ions in wastewater. Silica gel modified with pentadentate ligand iminodisuccinic acid displayed the highest adsorption capacity of 14.4 mg/g for Fe3+. The adsorption kinetics and thermodynamics of this adsorbent were studied, and the influences of concentration of Fe3+, temperature, rotation speed and coexisting ions on the adsorption were investigated. The experiment results showed that the adsorbent had a relatively fast initial adsorption behavior for Fe3+, and the pseudo-second-order model could better describe the adsorption kinetics of the adsorbent. Freundlich isotherm model was more suitable for describing equilibrium data, and the adsorption process was exothermic and non-spontaneous. Increasing the concentration and temperature could improve the adsorption capacity of Fe3+ on IDS-Silica, while increasing speed could shorten time to reach adsorption equilibrium. Other interfering ions had no effects on adsorption of Fe3+ except for Cu2+. Furthermore, IDS-Silica had good repeatability for adsorption of Fe3+. This work provided a new and efficient adsorption material for removing Fe3+ in wastewater, and also provided a theoretical reference for developing chelating adsorption material modified with pentadentate ligand iminodisuccinic acid.
The self-made silica gels functionalized with various multidentate ligands were used as adsorbents to explore the effects of ligand dentate numbers on the adsorption of common heavy metal ions in wastewater. Silica gel modified with pentadentate ligand iminodisuccinic acid displayed the highest adsorption capacity of 14.4 mg/g for Fe3+. The adsorption kinetics and thermodynamics of this adsorbent were studied, and the influences of concentration of Fe3+, temperature, rotation speed and coexisting ions on the adsorption were investigated. The experiment results showed that the adsorbent had a relatively fast initial adsorption behavior for Fe3+, and the pseudo-second-order model could better describe the adsorption kinetics of the adsorbent. Freundlich isotherm model was more suitable for describing equilibrium data, and the adsorption process was exothermic and non-spontaneous. Increasing the concentration and temperature could improve the adsorption capacity of Fe3+ on IDS-Silica, while increasing speed could shorten time to reach adsorption equilibrium. Other interfering ions had no effects on adsorption of Fe3+ except for Cu2+. Furthermore, IDS-Silica had good repeatability for adsorption of Fe3+. This work provided a new and efficient adsorption material for removing Fe3+ in wastewater, and also provided a theoretical reference for developing chelating adsorption material modified with pentadentate ligand iminodisuccinic acid.
2022, 50(2): 310-316
doi: 10.19756/j.issn.0253-3820.210552
Abstract:
Determination of thorium isotopic ratio 230Th/232Th in uranium materials by multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS) was presented for nuclear forensic. One piece of UO2 formed uranium pellet and three kinds of yellow cake powder were dissolved with ultrapure HNO3 (7.5 mol/L). Thorium was purified for analysis using a single column prepared with TBP resin bed, with which the sample was loaded and then Th was eluted with 4 mol/L HCl. Analyses were performed on Nu Plasma MC-ICP-MS and mass-bias correction were applied to the 230Th/232Th using bracketing measurements of U standard. An equation was proposed to correct the contribution from Th blank for calculating the 230Th/232Th of the uranium materials. The results showed that the 230Th/232Th ratios of the uranium pellet, yellow cake powder named YC1, yellow cake powder named YC2 and yellow cake powder named YC3 were (0.479±0.037), (1.376×10-4±4.8×10-6), (2.8582×10-3±2.2×10-6) and (2.8605×10-3±2.1×10-6) (k=2), respectively. The determined 230Th/232Th ratio of the uranium pellet agreed with the reference value. The yellow cake powder named YC2 and the yellow cake powder named YC3 were from the same source, whose 230Th/232Th ratios agreed with each other and differed distinctly from that of another sourced yellow cake powder named YC1. It was proved that the thorium isotope ratio 230Th/232Th was a newly discovered and time correlated fingerprint of uranium materials.
Determination of thorium isotopic ratio 230Th/232Th in uranium materials by multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS) was presented for nuclear forensic. One piece of UO2 formed uranium pellet and three kinds of yellow cake powder were dissolved with ultrapure HNO3 (7.5 mol/L). Thorium was purified for analysis using a single column prepared with TBP resin bed, with which the sample was loaded and then Th was eluted with 4 mol/L HCl. Analyses were performed on Nu Plasma MC-ICP-MS and mass-bias correction were applied to the 230Th/232Th using bracketing measurements of U standard. An equation was proposed to correct the contribution from Th blank for calculating the 230Th/232Th of the uranium materials. The results showed that the 230Th/232Th ratios of the uranium pellet, yellow cake powder named YC1, yellow cake powder named YC2 and yellow cake powder named YC3 were (0.479±0.037), (1.376×10-4±4.8×10-6), (2.8582×10-3±2.2×10-6) and (2.8605×10-3±2.1×10-6) (k=2), respectively. The determined 230Th/232Th ratio of the uranium pellet agreed with the reference value. The yellow cake powder named YC2 and the yellow cake powder named YC3 were from the same source, whose 230Th/232Th ratios agreed with each other and differed distinctly from that of another sourced yellow cake powder named YC1. It was proved that the thorium isotope ratio 230Th/232Th was a newly discovered and time correlated fingerprint of uranium materials.
