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2018 Volume 46 Issue 3
2018, 46(3): 301-310
doi: 10.11895/j.issn.0253-3820.171024
Abstract:
Heat shock protein 90 (HSP90) is a member of genetically conserved heat shock protein family. As an important molecular chaperone in eukaryotic cells, HSP90 plays a key regulatory role in maintaining cellular protein homeostasis. HSP90 clients encompass a wide range of proteins, thus HSP90 is involved in diverse biological process. With the deeper study, it is found that HSP90 takes an important part in the development and metastasis of cancer, and has become a promising target for the study of anticancer biology. We review the progress of HSP90 as molecular chaperone and its relationship with cancer.
Heat shock protein 90 (HSP90) is a member of genetically conserved heat shock protein family. As an important molecular chaperone in eukaryotic cells, HSP90 plays a key regulatory role in maintaining cellular protein homeostasis. HSP90 clients encompass a wide range of proteins, thus HSP90 is involved in diverse biological process. With the deeper study, it is found that HSP90 takes an important part in the development and metastasis of cancer, and has become a promising target for the study of anticancer biology. We review the progress of HSP90 as molecular chaperone and its relationship with cancer.
2018, 46(3): 311-316
doi: 10.11895/j.issn.0253-3820.171182
Abstract:
By using a double loop technique based on a set of mechanical transmission components and a flow path system, a double function of injection and fraction collection was realized. On the basis of double loop technique, a novel type of online/offline interface for two-dimensional liquid chromatography was designed to construct an efficient separation system coupling two different separation modes with a higher peak capacity, and the functions of the interface were evaluated. By means of connecting the interface to an HPLC system, the multiple functions of injection, fraction collection and injection again were fulfilled for preparation and purity analysis of 4 kinds of aromatic compounds. As for combination of 2 sets of HPLC system, 5 kinds of protein samples were separated preliminarily by strong cation exchange chromatography, and the components difficult to separate were collected and injected into reversed phase chromatographic system for further separation. Furthermore, the interface was applied to coupling two chromatographic systems in both strong cation exchange mode and microcolumn reversed-phase mode for the two-dimensional separation of bovine serum albumin enzymatic digest. When 1 mAU was set as the integral threshold, a total number of 292 peaks were identified. With the help of the online/offline interface, the preparation of microscale samples, fine separation of hardly separated samples and two-dimensional separation of complex samples were achieved flexibly. The result indicated that the system was a potent tool for the construction of two-dimensional chromatographic system and separation research.
By using a double loop technique based on a set of mechanical transmission components and a flow path system, a double function of injection and fraction collection was realized. On the basis of double loop technique, a novel type of online/offline interface for two-dimensional liquid chromatography was designed to construct an efficient separation system coupling two different separation modes with a higher peak capacity, and the functions of the interface were evaluated. By means of connecting the interface to an HPLC system, the multiple functions of injection, fraction collection and injection again were fulfilled for preparation and purity analysis of 4 kinds of aromatic compounds. As for combination of 2 sets of HPLC system, 5 kinds of protein samples were separated preliminarily by strong cation exchange chromatography, and the components difficult to separate were collected and injected into reversed phase chromatographic system for further separation. Furthermore, the interface was applied to coupling two chromatographic systems in both strong cation exchange mode and microcolumn reversed-phase mode for the two-dimensional separation of bovine serum albumin enzymatic digest. When 1 mAU was set as the integral threshold, a total number of 292 peaks were identified. With the help of the online/offline interface, the preparation of microscale samples, fine separation of hardly separated samples and two-dimensional separation of complex samples were achieved flexibly. The result indicated that the system was a potent tool for the construction of two-dimensional chromatographic system and separation research.
2018, 46(3): 317-323
doi: 10.11895/j.issn.0253-3820.171368
Abstract:
Hydrogel nanoparticles (NPs) were synthesized by precipitation polymerization method with N-isopropyl acrylamide (NIPAm), acrylic acid (Aac), N-tert butyl acrylamide (tBAM) and N, N'-methylene bisacrylamide (Bis) as thermosensitive monomer, negative monomer, hydrophobic monomer and crosslinker, respectively. The morphology of the resulting NPs was characterized by scanning electron microscopy (SEM), and the size and the particle size distribution were investigated by dynamic light scattering (DLS). The dynamics test was also carried out to investigate adsorption property of NPs. The results showed that NPs was spherical with uniform particle size and narrow distribution. NPs had the best adsorption performance to lysozyme when the monomer molar ratio was optimized to Aac 20%, tBAM 40%, NIPAm 38% and Bis 2%. Meanwhile, when the particle size of NPs decreased from 386.20 nm to 77.25 nm, the adsorption capacity increased gradually. The adsorption rate could reach up to 67.8% within 5 minutes. The thermosensitive of NPs provided a new candidate for the adsorption and separation of lysozyme with good reusability.
Hydrogel nanoparticles (NPs) were synthesized by precipitation polymerization method with N-isopropyl acrylamide (NIPAm), acrylic acid (Aac), N-tert butyl acrylamide (tBAM) and N, N'-methylene bisacrylamide (Bis) as thermosensitive monomer, negative monomer, hydrophobic monomer and crosslinker, respectively. The morphology of the resulting NPs was characterized by scanning electron microscopy (SEM), and the size and the particle size distribution were investigated by dynamic light scattering (DLS). The dynamics test was also carried out to investigate adsorption property of NPs. The results showed that NPs was spherical with uniform particle size and narrow distribution. NPs had the best adsorption performance to lysozyme when the monomer molar ratio was optimized to Aac 20%, tBAM 40%, NIPAm 38% and Bis 2%. Meanwhile, when the particle size of NPs decreased from 386.20 nm to 77.25 nm, the adsorption capacity increased gradually. The adsorption rate could reach up to 67.8% within 5 minutes. The thermosensitive of NPs provided a new candidate for the adsorption and separation of lysozyme with good reusability.
2018, 46(3): 324-331
doi: 10.11895/j.issn.0253-3820.171187
Abstract:
Novel compartment microparticles produced with double emulsion droplets as templates provide a protected internal space for material encapsulation. The effect of three-phase flow rate on the micro-droplet generation of double emulsion mechanism is available for reference to produce precise size and highly monodisperse particles. The influence of three-phase flow rate on the formation mode and size of the emulsion droplets was mainly investigated by making use of experiment and numerical simulation. The size of compound droplets decreases and the frequency increases with the increasing outer fluid flow rate. The monodispersity of the double emulsion reduces due to transition from dripping to narrowing jetting regime. Outer droplet size increases with the increasing flow rate of the middle fluid, whereas inner droplet size is the opposite. The frequency increases and then stabilizes, which leads to a widening regime. When Q2/Q1>6, multi-core type double emulsion droplets are produced. Droplet coalescence occurs when surfactant is not considered. As Q1 increases, there is an increasing tendency for inner drop size. The outer drop size is proportional to the sum of the inner and middle flow rate, and that is regardless of Q1/Q2. For drop size, ratio of core-shell and internal structure are precisely controlled by adjusting three-phase flow rate respectively.
Novel compartment microparticles produced with double emulsion droplets as templates provide a protected internal space for material encapsulation. The effect of three-phase flow rate on the micro-droplet generation of double emulsion mechanism is available for reference to produce precise size and highly monodisperse particles. The influence of three-phase flow rate on the formation mode and size of the emulsion droplets was mainly investigated by making use of experiment and numerical simulation. The size of compound droplets decreases and the frequency increases with the increasing outer fluid flow rate. The monodispersity of the double emulsion reduces due to transition from dripping to narrowing jetting regime. Outer droplet size increases with the increasing flow rate of the middle fluid, whereas inner droplet size is the opposite. The frequency increases and then stabilizes, which leads to a widening regime. When Q2/Q1>6, multi-core type double emulsion droplets are produced. Droplet coalescence occurs when surfactant is not considered. As Q1 increases, there is an increasing tendency for inner drop size. The outer drop size is proportional to the sum of the inner and middle flow rate, and that is regardless of Q1/Q2. For drop size, ratio of core-shell and internal structure are precisely controlled by adjusting three-phase flow rate respectively.
2018, 46(3): 332-341
doi: 10.11895/j.issn.0253-3820.171007
Abstract:
In this work, two chiral chloride probes were used to differentiate landiolol hydrochloride by mass spectrometry. Two chiral chloride probe reagents, N-(p-Tosyl)-L-phenylalaninyl chloride (TSPC) and (-)-Camphanic acid chloride, were chosen to react with landiolol hydrochloride and its stereoisomers to form covalent bonding derivatives, which enlarged the difference of stereo structure between landiolol and its stereoisomers. Result of tandem mass spectrometry showed that fragment from derivative products prefers to losing water to form fragment ions m/z 793 and m/z 672. The relative abundance of ions m/z 793 and m/z 672 was quite different in each isomer. The fragment ions m/z 603 from (-)-Camphanic acid chloride derivative products showed distinction relative abundance because of the different stability of each stereoisomers, which gave rise to the enlarged difference of stereo structure between landiolol and its stereoisomers. By comparing the different relative abundance ratio of analyte and each stereoisomer in MS/MS spectra, we could realize recognization landiolol hydrochloride and its stereoisomers. Accurate masses of precursor and fragment ions were confirmed on an IT-TOF mass spectrometer. This method by using ion-trap mass spectrometry could rapidly and simply differentiate landiolol hydrochloride and its stereoisomers. This work could also contribute to differentiation and discrimination of landiolol hydrochloride and its stereoisomers.
In this work, two chiral chloride probes were used to differentiate landiolol hydrochloride by mass spectrometry. Two chiral chloride probe reagents, N-(p-Tosyl)-L-phenylalaninyl chloride (TSPC) and (-)-Camphanic acid chloride, were chosen to react with landiolol hydrochloride and its stereoisomers to form covalent bonding derivatives, which enlarged the difference of stereo structure between landiolol and its stereoisomers. Result of tandem mass spectrometry showed that fragment from derivative products prefers to losing water to form fragment ions m/z 793 and m/z 672. The relative abundance of ions m/z 793 and m/z 672 was quite different in each isomer. The fragment ions m/z 603 from (-)-Camphanic acid chloride derivative products showed distinction relative abundance because of the different stability of each stereoisomers, which gave rise to the enlarged difference of stereo structure between landiolol and its stereoisomers. By comparing the different relative abundance ratio of analyte and each stereoisomer in MS/MS spectra, we could realize recognization landiolol hydrochloride and its stereoisomers. Accurate masses of precursor and fragment ions were confirmed on an IT-TOF mass spectrometer. This method by using ion-trap mass spectrometry could rapidly and simply differentiate landiolol hydrochloride and its stereoisomers. This work could also contribute to differentiation and discrimination of landiolol hydrochloride and its stereoisomers.
2018, 46(3): 342-347
doi: 10.11895/j.issn.0253-3820.171418
Abstract:
Ultramicroelectrode was usually used in scanning electrochemical microscope (SECM) as a probe. The redox reaction on the probe is a diffusion process. But the fast moving of probe in SECM will affect the diffusion process, resulting in unclear obtained images. A new SECM image-processing technique was proposed in this paper involving combination of LoG algorithm and New edge-directed interpolation (NEDI) interpolation algorithm. LoG algorithm is helpful for the clarity of SECM images, but leading to some loss of edge information. Fortunately, NEDI algorithm based on edge directed interpolation can solve this problem well. Two substrates with gold interdigitated electrode and gold electrode array were prepared by ion sputtering method. The SECM images were obtained of the gold interdigitated electrode, gold electrode array and ITO substrate printed with fingerprints. The corresponding images treated by LoG filter and these for NEDI interpolation were compared and analyzed. The image-processing technique combining the LoG algorithm with the NEDI interpolation algorithm can significantly improve the clarity and resolution of SECM image.
Ultramicroelectrode was usually used in scanning electrochemical microscope (SECM) as a probe. The redox reaction on the probe is a diffusion process. But the fast moving of probe in SECM will affect the diffusion process, resulting in unclear obtained images. A new SECM image-processing technique was proposed in this paper involving combination of LoG algorithm and New edge-directed interpolation (NEDI) interpolation algorithm. LoG algorithm is helpful for the clarity of SECM images, but leading to some loss of edge information. Fortunately, NEDI algorithm based on edge directed interpolation can solve this problem well. Two substrates with gold interdigitated electrode and gold electrode array were prepared by ion sputtering method. The SECM images were obtained of the gold interdigitated electrode, gold electrode array and ITO substrate printed with fingerprints. The corresponding images treated by LoG filter and these for NEDI interpolation were compared and analyzed. The image-processing technique combining the LoG algorithm with the NEDI interpolation algorithm can significantly improve the clarity and resolution of SECM image.
2018, 46(3): 348-353
doi: 10.11895/j.issn.0253-3820.171300
Abstract:
A capacitively coupled contactless conductivity detector for high performance liquid chromatography was developed. The detector was consisted of a signal generator, a signal amplifier, and a pair of tubular electrodes. A plastic connecting tube following the separation column was threaded through the two tubular electrodes. When the separated components passed the region between two tubular electrodes, they would be sensed. The instrumental parameters of this detector were investigated, including the internal diameter of connecting tube, the frequency and voltage of excitation signal, electrodes length, and the gap between two electrodes. The 0.5 mm of internal diameter of connecting tube, 70 kHz of excitation frequency, 60 V of excitation voltage, 10 mm of electrodes length and 1.5 mm of gap between two electrodes were finally found to be the best working conditions for the detector. This HPLC-C4D (capacitively coupled contactless conductivity detector) was applied to the analysis of oleic and linoleic acids in Brucea javanica oil. The chromatographic peak area was linear with concentration for oleic and linoleic acids in 5-1000 μg/mL, and the limit of detection reached 2.5 μg/mL and 1.0 μg/mL, respectively. The results demonstrate that the present method is sensitive and accurate, proving this homemade contactless conductivity detector has a great application potential for pharmaceutical analysis in future development.
A capacitively coupled contactless conductivity detector for high performance liquid chromatography was developed. The detector was consisted of a signal generator, a signal amplifier, and a pair of tubular electrodes. A plastic connecting tube following the separation column was threaded through the two tubular electrodes. When the separated components passed the region between two tubular electrodes, they would be sensed. The instrumental parameters of this detector were investigated, including the internal diameter of connecting tube, the frequency and voltage of excitation signal, electrodes length, and the gap between two electrodes. The 0.5 mm of internal diameter of connecting tube, 70 kHz of excitation frequency, 60 V of excitation voltage, 10 mm of electrodes length and 1.5 mm of gap between two electrodes were finally found to be the best working conditions for the detector. This HPLC-C4D (capacitively coupled contactless conductivity detector) was applied to the analysis of oleic and linoleic acids in Brucea javanica oil. The chromatographic peak area was linear with concentration for oleic and linoleic acids in 5-1000 μg/mL, and the limit of detection reached 2.5 μg/mL and 1.0 μg/mL, respectively. The results demonstrate that the present method is sensitive and accurate, proving this homemade contactless conductivity detector has a great application potential for pharmaceutical analysis in future development.
2018, 46(3): 354-363
doi: 10.11895/j.issn.0253-3820.171144
Abstract:
A novel Schiff base probe 4'-hydroxy-3'-((2-pyridin-2-ylmethylimino) methyl)-4-biphenyl carbonitrile (HPBC) for dual sensing of Zn2+and CN- was synthesized and characterized by various techniques such as UV-Vis, fluorescence, HRMS and NMR spectroscopy. HPBC was highly selective toward these two ions with different fluorescence signals in two different media. In EtOH-H2O (2:3, V/V; HEPES, pH 7.4), HPBC selectively bound Zn2+ to form a 1:1 ligand/metal complex. Addition of Zn2+ to the solution of HPBC resulted in a blue shift (Δλ=15 nm) with a pronounced fluorescence enhancement at 468 nm, while there was no enhancement in the presence of other metal ions, especially Cd2+. HPBC displayed an "ON-OFF-ON" mode fluorescence change with alternative addition of Zn2+ and EDTA. Hence, HPBC is a reversible and reusable sensor for Zn2+. The dynamic range of the assay is linear up to 4.0 μmol/L Zn2+ ion and the limit of detection was 36.5 nmol/L, which was thousand fold lower than the WHO guideline (about 76 μmol/L) for drinking water. The fluorescence response of HPBC toward Zn2+ was pH-dependent, and the maximal signal was observed at near neutral pH values, which makes it suitable for application in physiological conditions. Cell imaging studies demonstrate that this sensor is capable of sensing Zn2+ in living cells. In DMSO-H2O (3:7, V/V) medium, addition of cyanide ion to HPBC led to deprotonation of the phenol hydrogen, resulting in a color change from colorless to pale yellow and a significant fluorescence enhancement at 510 nm. The probe exhibited high selectivity and sensitivity for CN- ion and the detection limit was 5.75×10-7 mol/L. Finally, the use of a test strip of probe HPBC to detect cyanide was reported.
A novel Schiff base probe 4'-hydroxy-3'-((2-pyridin-2-ylmethylimino) methyl)-4-biphenyl carbonitrile (HPBC) for dual sensing of Zn2+and CN- was synthesized and characterized by various techniques such as UV-Vis, fluorescence, HRMS and NMR spectroscopy. HPBC was highly selective toward these two ions with different fluorescence signals in two different media. In EtOH-H2O (2:3, V/V; HEPES, pH 7.4), HPBC selectively bound Zn2+ to form a 1:1 ligand/metal complex. Addition of Zn2+ to the solution of HPBC resulted in a blue shift (Δλ=15 nm) with a pronounced fluorescence enhancement at 468 nm, while there was no enhancement in the presence of other metal ions, especially Cd2+. HPBC displayed an "ON-OFF-ON" mode fluorescence change with alternative addition of Zn2+ and EDTA. Hence, HPBC is a reversible and reusable sensor for Zn2+. The dynamic range of the assay is linear up to 4.0 μmol/L Zn2+ ion and the limit of detection was 36.5 nmol/L, which was thousand fold lower than the WHO guideline (about 76 μmol/L) for drinking water. The fluorescence response of HPBC toward Zn2+ was pH-dependent, and the maximal signal was observed at near neutral pH values, which makes it suitable for application in physiological conditions. Cell imaging studies demonstrate that this sensor is capable of sensing Zn2+ in living cells. In DMSO-H2O (3:7, V/V) medium, addition of cyanide ion to HPBC led to deprotonation of the phenol hydrogen, resulting in a color change from colorless to pale yellow and a significant fluorescence enhancement at 510 nm. The probe exhibited high selectivity and sensitivity for CN- ion and the detection limit was 5.75×10-7 mol/L. Finally, the use of a test strip of probe HPBC to detect cyanide was reported.
2018, 46(3): 364-372
doi: 10.11895/j.issn.0253-3820.171161
Abstract:
The biomass multi-elements self-doped TiO2 was synthesized simultaneously by ultrasonic irradiation assisted sol-gel method, and characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction(XRD), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (UV-Vis-DRS), Fourier transform infrared (FT-IR) spectroscopy, and photoluminescence (PL). The characterization results showed that, multiple elements, C, N, P, Cl and K, were doped in the composite TiO2. Compared with pure TiO2, the band gap of the composite catalyst was narrowed by 0.21 eV, and possessed more surface hydroxyl radical and active sites, lower recombination rate of photo-generated carriers, higher crystallinity and higher specific surface area. The photocatalytic ability of the composite catalyst was studied, using methylene blue (MB) as target pollutant. The experimental results showed that, under visible light irradiation, the degradation efficiency of methylene blue was up to 98% after photocatalytic reaction for two hours by the composite catalyst.
The biomass multi-elements self-doped TiO2 was synthesized simultaneously by ultrasonic irradiation assisted sol-gel method, and characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction(XRD), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (UV-Vis-DRS), Fourier transform infrared (FT-IR) spectroscopy, and photoluminescence (PL). The characterization results showed that, multiple elements, C, N, P, Cl and K, were doped in the composite TiO2. Compared with pure TiO2, the band gap of the composite catalyst was narrowed by 0.21 eV, and possessed more surface hydroxyl radical and active sites, lower recombination rate of photo-generated carriers, higher crystallinity and higher specific surface area. The photocatalytic ability of the composite catalyst was studied, using methylene blue (MB) as target pollutant. The experimental results showed that, under visible light irradiation, the degradation efficiency of methylene blue was up to 98% after photocatalytic reaction for two hours by the composite catalyst.
2018, 46(3): 373-378
doi: 10.11895/j.issn.0253-3820.170353
Abstract:
One-step green synthetic approach, with bovine serum albumin (BSA) as stabilizer and reductant, was developed for preparation of BSA hybrid fluorescence gold nanoclusters (AuNCs@BSA). The prepared AuNCs@BSA exhibited strong red fluorescence under UV light illumination. Upon excited at 360 nm, the fluorescence spectrum of AuNCs@BSA exhibited maximum emission peak at 635 nm. AuNCs@BSA was presented as uniform spherical morphology with diameter at (2.0±0.05) nm. The fluorescence of AuNCs@BSA could be quenched by Hg2+ because of its metallophilic reaction. Based on the fluorescent spectrometry, a rapid detection system was developed for Hg2+ detection in tap water. The AuNCs@BSA amount, pH and buffer system were optimized in this study. According to optimization results, ultrapure water (pH 5.0) was selected to dilute the AuNCs@BSA by 100 times, and 50 μL/well of AuNCs@BSA dilution was applied to detect mercury ion in tap water. Under the optimized conditions, the detection could be completed within 3 min, the fluorescence intensity of the system was linearly proportional to the concentration of mercury ion in the range of 0.5-900 μg/L with linear equations y=-26.76lgx + 803.1 (0.5-75 μg/L, R2=0.9951) and y=-0.27x+762.02 (75-900 μg/L, R2=0.9959). The limit of detection was 0.14 μg/L(3σ). The average recoveries in spiked tape water samples ranged from 86.8%-113.4% with relative standard deviation of less than 15%. The result implied that the developed method was able to apply to detect mercury ion rapidly, sensitively and conveniently.
One-step green synthetic approach, with bovine serum albumin (BSA) as stabilizer and reductant, was developed for preparation of BSA hybrid fluorescence gold nanoclusters (AuNCs@BSA). The prepared AuNCs@BSA exhibited strong red fluorescence under UV light illumination. Upon excited at 360 nm, the fluorescence spectrum of AuNCs@BSA exhibited maximum emission peak at 635 nm. AuNCs@BSA was presented as uniform spherical morphology with diameter at (2.0±0.05) nm. The fluorescence of AuNCs@BSA could be quenched by Hg2+ because of its metallophilic reaction. Based on the fluorescent spectrometry, a rapid detection system was developed for Hg2+ detection in tap water. The AuNCs@BSA amount, pH and buffer system were optimized in this study. According to optimization results, ultrapure water (pH 5.0) was selected to dilute the AuNCs@BSA by 100 times, and 50 μL/well of AuNCs@BSA dilution was applied to detect mercury ion in tap water. Under the optimized conditions, the detection could be completed within 3 min, the fluorescence intensity of the system was linearly proportional to the concentration of mercury ion in the range of 0.5-900 μg/L with linear equations y=-26.76lgx + 803.1 (0.5-75 μg/L, R2=0.9951) and y=-0.27x+762.02 (75-900 μg/L, R2=0.9959). The limit of detection was 0.14 μg/L(3σ). The average recoveries in spiked tape water samples ranged from 86.8%-113.4% with relative standard deviation of less than 15%. The result implied that the developed method was able to apply to detect mercury ion rapidly, sensitively and conveniently.
2018, 46(3): 379-385
doi: 10.11895/j.issn.0253-3820.171256
Abstract:
A highly sensitive fluorescent probe TZ based on a novel Schiff's base was prepared for detection of Mg2+. It was constituted by introducing dansyl chloride and 2-hydroxy-1-naphthaldehyde through amino and hydrazide groups on p-aminobenzoyl hydrazide. The recognition mechanism of the fluorescent probe TZ for Mg2+ was studied by electrospray ionization mass spectrometry (ESI-MS), UV-vis and fluorescence spectra. UV-vis spectra showed that the probe TZ had a characteristic absorption peak of naphthalene aldehyde at 386.5 nm, and a new absorption peak at 411 nm was observed after coordination between TZ with Mg2+. A sharp isobestic point was obtained at 400 nm. Fluorescence spectra showed that the emission wavelength was red-shifted to 400 nm upon the addition of Mg2+ into probe TZ. The fluorescence intensity was enhanced by 10 times at the emission wavelength of 468 nm and the quantum yield of 0.57 was obtained. Moreover, chemical bond energy transfer was found when 2-hydroxy-1-naphthaldehyde was coordinated with Mg2+. When the other metal ions (Li+, Na+, K+, Zn2+, Ca2+, Mn2+, Cd2+, Pb2+, Ag+, etc.) were added into TZ, no significant change of fluorescence intensity was observed. It indicated that TZ had high selectivity to Mg2+. Furthermore, the recognition of TZ to Mg2+ was not interfered by other competing metal ions. ESI-MS titration and Job's plot analysis confirmed that 1:1 complexation stoichiometry between TZ and Mg2+ was obtained. The lowest detection limit was up to 0.13 μmol/L.
A highly sensitive fluorescent probe TZ based on a novel Schiff's base was prepared for detection of Mg2+. It was constituted by introducing dansyl chloride and 2-hydroxy-1-naphthaldehyde through amino and hydrazide groups on p-aminobenzoyl hydrazide. The recognition mechanism of the fluorescent probe TZ for Mg2+ was studied by electrospray ionization mass spectrometry (ESI-MS), UV-vis and fluorescence spectra. UV-vis spectra showed that the probe TZ had a characteristic absorption peak of naphthalene aldehyde at 386.5 nm, and a new absorption peak at 411 nm was observed after coordination between TZ with Mg2+. A sharp isobestic point was obtained at 400 nm. Fluorescence spectra showed that the emission wavelength was red-shifted to 400 nm upon the addition of Mg2+ into probe TZ. The fluorescence intensity was enhanced by 10 times at the emission wavelength of 468 nm and the quantum yield of 0.57 was obtained. Moreover, chemical bond energy transfer was found when 2-hydroxy-1-naphthaldehyde was coordinated with Mg2+. When the other metal ions (Li+, Na+, K+, Zn2+, Ca2+, Mn2+, Cd2+, Pb2+, Ag+, etc.) were added into TZ, no significant change of fluorescence intensity was observed. It indicated that TZ had high selectivity to Mg2+. Furthermore, the recognition of TZ to Mg2+ was not interfered by other competing metal ions. ESI-MS titration and Job's plot analysis confirmed that 1:1 complexation stoichiometry between TZ and Mg2+ was obtained. The lowest detection limit was up to 0.13 μmol/L.
2018, 46(3): 386-392
doi: 10.11895/j.issn.0253-3820.171041
Abstract:
A sensitive method was proposed for determination of 13 kinds of sulfonylurea herbicides residues in aquatic products by solid phase extraction-ultra performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (SPE-UPLC-MS/MS). The edible part of carp, penaeus vannamei, crab, clam and sea cucumber were collected and homogenized. Analytes was extracted with ethyl acetate, and then cleaned up by MAX solid phase extraction column. Qualitation of the analytes was achieved with multiple reaction monitoring (MRM) and the external standard method was used for quantification. The 13 kinds of sulfonylurea herbicides showed good linearity in the concentration range of 5.0-100.0 μg/L respectively. The detection limits of the 13 analytes were 1.0 μg/kg, and the limit of quantification was 2.0 μg/kg. The average recoveries ranged from 75.4% to 118.3% with relative standard deviations from 2.1% to 14.5%. The 13 target analytes were not detected in grass carp, carp, sea cucumber, prawn, turbot of breeding and crabs from the market. The halosulfuron-methyl was detected in the edible tissues of crabs exposed to a 1.0 mg/L halosulfuron-methyl solution for 24, 48 and 72 h, and the concentrations were 6.20, 12.1 and 16.6 μg/kg respectively. The method can be stable and sensitive, and is applied to the determination of 13 kinds of sulfonylurea herbicides residues in aquatic products.
A sensitive method was proposed for determination of 13 kinds of sulfonylurea herbicides residues in aquatic products by solid phase extraction-ultra performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (SPE-UPLC-MS/MS). The edible part of carp, penaeus vannamei, crab, clam and sea cucumber were collected and homogenized. Analytes was extracted with ethyl acetate, and then cleaned up by MAX solid phase extraction column. Qualitation of the analytes was achieved with multiple reaction monitoring (MRM) and the external standard method was used for quantification. The 13 kinds of sulfonylurea herbicides showed good linearity in the concentration range of 5.0-100.0 μg/L respectively. The detection limits of the 13 analytes were 1.0 μg/kg, and the limit of quantification was 2.0 μg/kg. The average recoveries ranged from 75.4% to 118.3% with relative standard deviations from 2.1% to 14.5%. The 13 target analytes were not detected in grass carp, carp, sea cucumber, prawn, turbot of breeding and crabs from the market. The halosulfuron-methyl was detected in the edible tissues of crabs exposed to a 1.0 mg/L halosulfuron-methyl solution for 24, 48 and 72 h, and the concentrations were 6.20, 12.1 and 16.6 μg/kg respectively. The method can be stable and sensitive, and is applied to the determination of 13 kinds of sulfonylurea herbicides residues in aquatic products.
2018, 46(3): 393-399
doi: 10.11895/j.issn.0253-3820.171281
Abstract:
Content and type of triacylglycerols (TAGs) in edible oils are closely related with our health, it is of significance to develop a fast and high-efficiency method for the determination of TAGs. In this manuscript, a fast and direct method for qualitative analysis of TAGs was established using matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR-MS). 2,5-DHB was employed as matrix and dichloromethanewas used as solvent for dissolving edible oils. With laser power of 15%, laser frequency of 100 Hz and 100 laser shots, repeatability was evaluated using relative standard deviation (RSD) and less than 10% was obtained. Different kinds of edible oils could be directly distinguished from each other using MS and MS/MS results.With confidence level of 95%, principal component analysis (PCA) results show that 34 different kinds of edible oils were clearly classified. Using this method 5% doped canola in olive was identified directly,indicating that MALDI-FTICR-MS has the potential for rapid analyzing and screening edible oils.
Content and type of triacylglycerols (TAGs) in edible oils are closely related with our health, it is of significance to develop a fast and high-efficiency method for the determination of TAGs. In this manuscript, a fast and direct method for qualitative analysis of TAGs was established using matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR-MS). 2,5-DHB was employed as matrix and dichloromethanewas used as solvent for dissolving edible oils. With laser power of 15%, laser frequency of 100 Hz and 100 laser shots, repeatability was evaluated using relative standard deviation (RSD) and less than 10% was obtained. Different kinds of edible oils could be directly distinguished from each other using MS and MS/MS results.With confidence level of 95%, principal component analysis (PCA) results show that 34 different kinds of edible oils were clearly classified. Using this method 5% doped canola in olive was identified directly,indicating that MALDI-FTICR-MS has the potential for rapid analyzing and screening edible oils.
2018, 46(3): 400-405
doi: 10.11895/j.issn.0253-3820.171359
Abstract:
Traditional Chinese Medicine massage is a kind of physiotherapy which affects on specific parts of the body surface by means of training to regulate the function of the body to achieve the therapeutic effect. In this work, under positive detection model, the chemical fingerprint of exhaled breath from volunteers before and after receiving Traditional Chinese Medicine massage within m/z 50-1000 were detected by extractive electrospray ionization-mass spectrometry (EESI-MS). And through high resolution mass spectrometry analysis, the metabolites such as epinephrine (m/z 184.0889), 3-(3-hydroxyphenyl) propionic acid (m/z 167.0615) and L-tryptophan (m/z 205.0933) were successfully identified. Besides, chemical fingerprints of volunteers before and after receiving Traditional Chinese Medicine massage under different health condition were clearly differentiated via partial least squares discrimination analysis (PLS-DA). The results showed that Traditional Chinese Medicine massage could significantly change the metabolic process of volunteers. Moreover, it further indicated that the established method could provide a real time fashion to follow metabolic changes caused by Traditional Chinese Medicine massage.
Traditional Chinese Medicine massage is a kind of physiotherapy which affects on specific parts of the body surface by means of training to regulate the function of the body to achieve the therapeutic effect. In this work, under positive detection model, the chemical fingerprint of exhaled breath from volunteers before and after receiving Traditional Chinese Medicine massage within m/z 50-1000 were detected by extractive electrospray ionization-mass spectrometry (EESI-MS). And through high resolution mass spectrometry analysis, the metabolites such as epinephrine (m/z 184.0889), 3-(3-hydroxyphenyl) propionic acid (m/z 167.0615) and L-tryptophan (m/z 205.0933) were successfully identified. Besides, chemical fingerprints of volunteers before and after receiving Traditional Chinese Medicine massage under different health condition were clearly differentiated via partial least squares discrimination analysis (PLS-DA). The results showed that Traditional Chinese Medicine massage could significantly change the metabolic process of volunteers. Moreover, it further indicated that the established method could provide a real time fashion to follow metabolic changes caused by Traditional Chinese Medicine massage.
2018, 46(3): 406-412
doi: 10.11895/j.issn.0253-3820.171348
Abstract:
As a promising new molecular imaging technique, mass spectrometry imaging (MSI) has attracted more and more attention in the field of biomedicine. A method of air flow assisted ionization-ultra high resolution mass spectrometry-based mass spectrometric imaging (AFAI-MSI) was developed to profile endogenous metabolites in rat kidney tissue in this study. Rat kidneys were collected and cut into frozen tissue sections, and then were analyzed on an AFAI-MSI system in positive ion mode using acetonitrile-isopmpyl alcohol-water (4:4:2, V/V, 5 μL/min) as spray solvent, N2 as spray gas (0.6 MPa) and air as assisting gas (45 L/min). The mass range and resolution were set to be 70-1000 Da and 70000, respectively. As a result, a total of 38 metabolites, including organic amines, sugars, vitamins, peptides, neurotransmitters, organic acids, phospholipids, sphingolipids, glyceride, and cholesterol esters, were identified and imaged to characterize their tissue-specific distribution in kidney tissues, and some metabolites, such as choline, acetylcoline, betaine, phoshocholine, and glycerophosphocholine were found to have distinct distribution along the cortex-medulla axis, which may be involved in the formation of osmotic pressure gradient in the kidney. The proposed ultra high resolution mass spectrometry based AFAI-MSI method could work without sample pretreatment, showed high sensitivity and wide metabolite coverage, and was expected to provide a new analytical approach for the research of in situ characterization and metabolic regulation mechanism of endogenous metabolites in kidney.
As a promising new molecular imaging technique, mass spectrometry imaging (MSI) has attracted more and more attention in the field of biomedicine. A method of air flow assisted ionization-ultra high resolution mass spectrometry-based mass spectrometric imaging (AFAI-MSI) was developed to profile endogenous metabolites in rat kidney tissue in this study. Rat kidneys were collected and cut into frozen tissue sections, and then were analyzed on an AFAI-MSI system in positive ion mode using acetonitrile-isopmpyl alcohol-water (4:4:2, V/V, 5 μL/min) as spray solvent, N2 as spray gas (0.6 MPa) and air as assisting gas (45 L/min). The mass range and resolution were set to be 70-1000 Da and 70000, respectively. As a result, a total of 38 metabolites, including organic amines, sugars, vitamins, peptides, neurotransmitters, organic acids, phospholipids, sphingolipids, glyceride, and cholesterol esters, were identified and imaged to characterize their tissue-specific distribution in kidney tissues, and some metabolites, such as choline, acetylcoline, betaine, phoshocholine, and glycerophosphocholine were found to have distinct distribution along the cortex-medulla axis, which may be involved in the formation of osmotic pressure gradient in the kidney. The proposed ultra high resolution mass spectrometry based AFAI-MSI method could work without sample pretreatment, showed high sensitivity and wide metabolite coverage, and was expected to provide a new analytical approach for the research of in situ characterization and metabolic regulation mechanism of endogenous metabolites in kidney.
2018, 46(3): 413-421
doi: 10.11895/j.issn.0253-3820.171149
Abstract:
A simple, rapid and sensitive upconversion immunochromatographic assay (UICA) was developed to detect imidaclothiz using NaYF4:Yb,Er upconversion nanoparticles (UCNPs) labeled with anti-imidaclothiz monoclonal antibody. The amino-modified UCNPs were conjugated with anti-imidaclothiz monoclonal antibody to prepare the UICA strip, which could realize the quantitative detection of imidaclothiz using a fluorescence photometer with an external 980 nm laser source. The working conditions of the UICA were systematically optimized, and the sensitivity, specificity, precision and accuracy were assessed by the studies of cross-reactivity (CR), spiked recovery and validation with HPLC. Under the optimal conditions (pH 8.0, 0.3 mol/L NaCl, 2.5% methanol and 0.2% PEG2000), the UICA could be completed in 25 min for the detection of imidaclothiz. The half-maximal inhibition concentration (IC50), limit of detection (IC10) and linear range (IC10-IC90) were 97.37 ng/mL, 26.30 ng/mL and 26.30-363.08 ng/mL, respectively. The UICA had no CR with the analogues of imidaclothiz except for imidacloprid. The average spiked recoveries were 71.8%-97.2% with the relative standard deviations of 0.7%-10.7% in the matrices of paddy water, soil, pear, peach, wheat, cucumber, tomato and rice. The detection results of UICA for the authentic paddy water and pear samples were consistent with that of high performance liquid chromatography (HPLC).
A simple, rapid and sensitive upconversion immunochromatographic assay (UICA) was developed to detect imidaclothiz using NaYF4:Yb,Er upconversion nanoparticles (UCNPs) labeled with anti-imidaclothiz monoclonal antibody. The amino-modified UCNPs were conjugated with anti-imidaclothiz monoclonal antibody to prepare the UICA strip, which could realize the quantitative detection of imidaclothiz using a fluorescence photometer with an external 980 nm laser source. The working conditions of the UICA were systematically optimized, and the sensitivity, specificity, precision and accuracy were assessed by the studies of cross-reactivity (CR), spiked recovery and validation with HPLC. Under the optimal conditions (pH 8.0, 0.3 mol/L NaCl, 2.5% methanol and 0.2% PEG2000), the UICA could be completed in 25 min for the detection of imidaclothiz. The half-maximal inhibition concentration (IC50), limit of detection (IC10) and linear range (IC10-IC90) were 97.37 ng/mL, 26.30 ng/mL and 26.30-363.08 ng/mL, respectively. The UICA had no CR with the analogues of imidaclothiz except for imidacloprid. The average spiked recoveries were 71.8%-97.2% with the relative standard deviations of 0.7%-10.7% in the matrices of paddy water, soil, pear, peach, wheat, cucumber, tomato and rice. The detection results of UICA for the authentic paddy water and pear samples were consistent with that of high performance liquid chromatography (HPLC).
2018, 46(3): 422-431
doi: 10.11895/j.issn.0253-3820.171436
Abstract:
Dissolved organic matter (DOM) is the most active fraction of compost organic matter. The presence of the redox-active functional groups in DOM allows it to act an electron shuttle to promote the electron transfer between microorganisms and terminal electron acceptors. In this study, the electron transfer capacities (ETCs) of compost DOM samples at eight different composting stages were determined by electrochemical method. The 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and Diquat dibro-mide monohydrate (DQ) were used to measured electron donating capacity (EDC) and electron accepting capacity (EAC) with working voltage 0.61 V/-0.49 V, respective. The evolution characteristics of the chemical structures and components were analyzed by combining the three-dimensional fluorescence spectra, fourier transform infrared (FTIR) spectra and elemental analysis. The results showed that the electron donating capacity (EDC) of DOMincreased from 16.850 μmol e-/(g C) to 22.077 μmol e-/(g C), The corresponding electron accepting capacity (EAC) decreased from 1.866 μmol e-/(g C)to 1.779 μmol e-/(g C). The results of three-dimensional fluorescence spectroscopy show that the relative contents of humuc-likeand protein-like components gradually increased and decreased, respectively, during the composting process. The humuc-like components were the main contributor for the ETC of DOM. FTIR spectra shows that there was no significant change in the hydroxyl and carboxyl group contentsof DOM during composting, suggesting no contribution of these function groups to the ETC of DOM. The elemental analysis showed that the content of oxygen in the DOM increased during the composting process, while the sulfur-containing group may be dominated contributor forits ETC.
Dissolved organic matter (DOM) is the most active fraction of compost organic matter. The presence of the redox-active functional groups in DOM allows it to act an electron shuttle to promote the electron transfer between microorganisms and terminal electron acceptors. In this study, the electron transfer capacities (ETCs) of compost DOM samples at eight different composting stages were determined by electrochemical method. The 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and Diquat dibro-mide monohydrate (DQ) were used to measured electron donating capacity (EDC) and electron accepting capacity (EAC) with working voltage 0.61 V/-0.49 V, respective. The evolution characteristics of the chemical structures and components were analyzed by combining the three-dimensional fluorescence spectra, fourier transform infrared (FTIR) spectra and elemental analysis. The results showed that the electron donating capacity (EDC) of DOMincreased from 16.850 μmol e-/(g C) to 22.077 μmol e-/(g C), The corresponding electron accepting capacity (EAC) decreased from 1.866 μmol e-/(g C)to 1.779 μmol e-/(g C). The results of three-dimensional fluorescence spectroscopy show that the relative contents of humuc-likeand protein-like components gradually increased and decreased, respectively, during the composting process. The humuc-like components were the main contributor for the ETC of DOM. FTIR spectra shows that there was no significant change in the hydroxyl and carboxyl group contentsof DOM during composting, suggesting no contribution of these function groups to the ETC of DOM. The elemental analysis showed that the content of oxygen in the DOM increased during the composting process, while the sulfur-containing group may be dominated contributor forits ETC.
2018, 46(3): 432-437
doi: 10.11895/j.issn.0253-3820.171435
Abstract:
Palladium hydrogel capped by β-cyclodextrins (Pdβ-CD) was prepared by a facile method with β-cyclodextrins and palladium(Ⅱ) chloride, which were then modified onto the surface of gold electrode. The morphology and structure of the as-prepared palladium hydrogel were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), while the electrochemistry behaviors of gold electrode modified by Pdβ-CD were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The results indicated the sensor had high electrochemistry response to hydrazine hydrate in the presence of K+, Na+, Mg2+, NH4+, Ni2+, Mn2+, Cl-, NO3-, SO42-, PO43-, HCOO-, C6H5O3-. Under the optimized conditions, the oxidized peak current showed linear relationship with the concentration of hydrazine hydrate in the concentration range of 25-950 μmol/L and the limit of detection (LOD) of 1.6 μmol/L(S/N=3).Owing to the facile preparation, high sensitivity and selectivity, the sensor has potential applications in determination of hydrazine hydrate in real water samples.
Palladium hydrogel capped by β-cyclodextrins (Pdβ-CD) was prepared by a facile method with β-cyclodextrins and palladium(Ⅱ) chloride, which were then modified onto the surface of gold electrode. The morphology and structure of the as-prepared palladium hydrogel were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), while the electrochemistry behaviors of gold electrode modified by Pdβ-CD were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The results indicated the sensor had high electrochemistry response to hydrazine hydrate in the presence of K+, Na+, Mg2+, NH4+, Ni2+, Mn2+, Cl-, NO3-, SO42-, PO43-, HCOO-, C6H5O3-. Under the optimized conditions, the oxidized peak current showed linear relationship with the concentration of hydrazine hydrate in the concentration range of 25-950 μmol/L and the limit of detection (LOD) of 1.6 μmol/L(S/N=3).Owing to the facile preparation, high sensitivity and selectivity, the sensor has potential applications in determination of hydrazine hydrate in real water samples.
2018, 46(3): 438-445
doi: 10.11895/j.issn.0253-3820.171183
Abstract:
MnO2 nanowires-reduced graphene oxide composite (MnO2-RGO) was used to modify glassy carbon electrodes (GCE) and applied for the electrochemical determination of dopamine (DA). The microstructure of MnO2 nanowires and MnO2-RGO nanocomposite material was characterized by scanning microscope and X-ray powder diffraction. Then the electrochemical reduction condition for preparing MnO2-RGO/GCE and experimental conditions for determining DA were optimized systematically. The electrochemical behavior of DA on the bare electrode and RGO or MnO2-RGO modified electrodes was also investigated in pH 3.5 phosphate buffer solution (PBS) by cyclic voltammetry. The results shows that the oxidation peaks of ascorbic acid (AA), dopamine (DA) and uric acid (UA) can be well separated and the peak to peak separations were 268 mV (AA-DA) and 128 mV (DA-UA), respectively. Moreover, the linear response ranges for the determination of DA were 0.06-1.0 μmol/L and 1.0-80 μmol/L with the detection limit of 1.0 nmol/L (S/N=3). The proposed method has been applied to the determination of dopamine in human blood serum sample with satisfactory results.
MnO2 nanowires-reduced graphene oxide composite (MnO2-RGO) was used to modify glassy carbon electrodes (GCE) and applied for the electrochemical determination of dopamine (DA). The microstructure of MnO2 nanowires and MnO2-RGO nanocomposite material was characterized by scanning microscope and X-ray powder diffraction. Then the electrochemical reduction condition for preparing MnO2-RGO/GCE and experimental conditions for determining DA were optimized systematically. The electrochemical behavior of DA on the bare electrode and RGO or MnO2-RGO modified electrodes was also investigated in pH 3.5 phosphate buffer solution (PBS) by cyclic voltammetry. The results shows that the oxidation peaks of ascorbic acid (AA), dopamine (DA) and uric acid (UA) can be well separated and the peak to peak separations were 268 mV (AA-DA) and 128 mV (DA-UA), respectively. Moreover, the linear response ranges for the determination of DA were 0.06-1.0 μmol/L and 1.0-80 μmol/L with the detection limit of 1.0 nmol/L (S/N=3). The proposed method has been applied to the determination of dopamine in human blood serum sample with satisfactory results.
2018, 46(3): 446-453
doi: 10.11895/j.issn.0253-3820.171280
Abstract:
A silver nanowires (AgNWs) flexible electrode was prepared using polydimethylsiloxane (PDMS) as the substrate and AgNWs as the conductive layer. It is easier to change the shapes and sizes of the flexible electrode due to its excellent stretchability and foldability. A square wave stripping voltammetry (SWSV) method for the detection of trace copper in water was established using the electrode as the working electrode. The characterization of AgNWs flexible electrode showed that the spread of AgNWs was uniform and the average resistance was 1.03 Ω. The data of electrochemical analysis showed that the properties of the electrode were superior to commercialized gold electrode and silver electrode. The effects of Bi3+ concentration, supporting electrolyte, pH value, enrichment potential and enrichment time were determined and optimized. We achieved the sharpest and highest peak of the SWSV curves for the detection of Cu2+ in the range of -0.3-0.3 V, which means the most sensitive detection, under the following conditions such as 0.5 mg/L Bi3+, 0.1 mol/L support electrolyte tartaric acid-sodium tartrate solution (pH, 4.8), 0.6 V of enrichment potential, and 600 s of enrichment time. Under such conditions, the linear detection range of Cu2+ concentration was from 0.001 mg/L to 0.100 mg/L and the detection limit was 9.27×10-5 mg/L. The advantages of this detection method are fast speed, high sensitivity and wide detection range. Therefore, it can not only meet the requirements for the copper ion detection but also provide a new method or experimental basis for the detection of other metal ions in water. In addition, the AgNWs flexible electrode has great potential in detections under special circumstances or instantaneous detections due to its wonderful flexibility and biocompatibility.
A silver nanowires (AgNWs) flexible electrode was prepared using polydimethylsiloxane (PDMS) as the substrate and AgNWs as the conductive layer. It is easier to change the shapes and sizes of the flexible electrode due to its excellent stretchability and foldability. A square wave stripping voltammetry (SWSV) method for the detection of trace copper in water was established using the electrode as the working electrode. The characterization of AgNWs flexible electrode showed that the spread of AgNWs was uniform and the average resistance was 1.03 Ω. The data of electrochemical analysis showed that the properties of the electrode were superior to commercialized gold electrode and silver electrode. The effects of Bi3+ concentration, supporting electrolyte, pH value, enrichment potential and enrichment time were determined and optimized. We achieved the sharpest and highest peak of the SWSV curves for the detection of Cu2+ in the range of -0.3-0.3 V, which means the most sensitive detection, under the following conditions such as 0.5 mg/L Bi3+, 0.1 mol/L support electrolyte tartaric acid-sodium tartrate solution (pH, 4.8), 0.6 V of enrichment potential, and 600 s of enrichment time. Under such conditions, the linear detection range of Cu2+ concentration was from 0.001 mg/L to 0.100 mg/L and the detection limit was 9.27×10-5 mg/L. The advantages of this detection method are fast speed, high sensitivity and wide detection range. Therefore, it can not only meet the requirements for the copper ion detection but also provide a new method or experimental basis for the detection of other metal ions in water. In addition, the AgNWs flexible electrode has great potential in detections under special circumstances or instantaneous detections due to its wonderful flexibility and biocompatibility.
2018, 46(3): 454-461
doi: 10.11895/j.issn.0253-3820.171175
Abstract:
An ultra performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method was developed for the determination of 11 kinds of aminoglycosides (AGs), including paromomycin, spectinomycin, tobramycin, gentamycin, kanamycin, hygromycin B, apramycin, streptomycin, dihydrostreptomycin, amikacin and neomycin in aquatic products. Samples were extracted by phosphate buffer solution, and purified on molecularly imprinted polymers (MIP) solid phase extraction column. After separated by Obelisc R chromatographic column, AGs were detected by UPLC-MS/MS. It showed a good linearity relationship in the AGs concentration range of 1.0-1000 ng/mL with the correlation coefficient R2>0.994. The limit of detection (LOD, S/N ≥ 3) was ranged from 1.0 μg/kg to 10.0 μg/kg, and the limit of quantitation (LOQ, S/N ≥ 10) was ranged from 2.0 μg/kg to 20.0 μg/kg. Besides, the average recoveries presented 78.4%-109.6% with the relative standard deviation (RSD, n=6) of 2.3%-14.9%. This method was successfully applied to the simultaneous determination of 11 kinds of AGs with high sensitivity in aquatic products.
An ultra performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method was developed for the determination of 11 kinds of aminoglycosides (AGs), including paromomycin, spectinomycin, tobramycin, gentamycin, kanamycin, hygromycin B, apramycin, streptomycin, dihydrostreptomycin, amikacin and neomycin in aquatic products. Samples were extracted by phosphate buffer solution, and purified on molecularly imprinted polymers (MIP) solid phase extraction column. After separated by Obelisc R chromatographic column, AGs were detected by UPLC-MS/MS. It showed a good linearity relationship in the AGs concentration range of 1.0-1000 ng/mL with the correlation coefficient R2>0.994. The limit of detection (LOD, S/N ≥ 3) was ranged from 1.0 μg/kg to 10.0 μg/kg, and the limit of quantitation (LOQ, S/N ≥ 10) was ranged from 2.0 μg/kg to 20.0 μg/kg. Besides, the average recoveries presented 78.4%-109.6% with the relative standard deviation (RSD, n=6) of 2.3%-14.9%. This method was successfully applied to the simultaneous determination of 11 kinds of AGs with high sensitivity in aquatic products.
