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1.
J Phys Chem Lett ; 14(16): 3844-3852, 2023 Apr 27.
Article in English | MEDLINE | ID: mdl-37067200

ABSTRACT

Cobalt phthalocyanine anchored on carbon material has attracted an enormous amount of attention due to its superior performance in electrocatalytic CO2 reduction. However, the interaction between cobalt phthalocyanine and the carbon substrate remains problematic, and the role of intrinsic carbon defects is unfortunately ignored in the anchoring of cobalt phthalocyanine on carbon. Herein, new interactions between the bridging N atoms of cobalt phthalocyanine and the edge defects of carbon have been discovered, which result in a novel model of anchoring of cobalt phthalocyanine on ketjen black carbon. Such anchored cobalt phthalocyanine has been found to be responsible for superior catalysis for electrochemical reduction of CO2 to CO with high selectivity and low overpotential.

2.
Dalton Trans ; 51(47): 18277-18283, 2022 Dec 06.
Article in English | MEDLINE | ID: mdl-36411978

ABSTRACT

Herein, sol-gel-synthesized α-Li2TiO3 was evaluated as a new promising anode material for lithium-ion batteries. The results show ultrastable release of discharge capacity within the range of 290-350 mA h g-1 in 400 cycles. Decent rate performances were also observed. A capacity of ca. 113 mA h g-1 was retained at a current density of 3 C. A 2 × 2 × 1 supercell of the lowest energy ordering structure was used in density functional theory simulations. The calculations show that in the intercalation process, Li+ preferentially enters the tetrahedral voids, leading to the activation of lithium-ion diffusion on the a-b plane with a minimal energy barrier of 0.06 eV (compared with 0.82 eV for the fully charged state). The activation of cation mobility at Li+ intercalation and insulator-conductor transition both contribute significantly to the ultrastability of the material. However, Li+ propagation along the c-axis is highly limited during the whole intercalation process. The enumeration of all the ordering structures on the tetrahedral sites shows two intermediate phases, α-Li2.25TiO3 and α-Li3.0TiO3, as observed from the formation energy convex hull.

3.
Dalton Trans ; 50(32): 11030-11038, 2021 Aug 28.
Article in English | MEDLINE | ID: mdl-34324616

ABSTRACT

With the development of electric vehicles, more and more attention has been paid to the kinetic performance of batteries, which is related to rapid charge/discharge and safety issues. To improve this aspect, Cu2Nb34O87 nanowires covered by nitrogen and sulfur co-doped carbon (Cu2Nb34O87/NSC nanowires) are prepared by electrospinning combined with surface coating. As-prepared Cu2Nb34O87/NSC nanowires present a high ion diffusion coefficient and electronic conductivity, showing good a kinetic performance. Specifically, they deliver a splendid capacity of 311.2 mA h g-1 at 1 C and a superior cycling stability with a capacity fading of 0.031% per cycle upon 1000 cycles. At the same time, the electrochemical and structural reversibility is fully discussed and demonstrated by ex situ XRD, ex situ SEM and ex situ XPS based on the redox couples of Cu2+/Cu+, Nb5+/Nb4+, and Nb4+/Nb3+. Contributing to peculiar physico-chemical properties, Cu2Nb34O87/NSC nanowires are expected to be a candidate material for the anode in lithium-ion batteries.

4.
Adv Manuf ; 9(1): 130-135, 2021.
Article in English | MEDLINE | ID: mdl-33425459

ABSTRACT

The World Health Organization emphasized the importance of goggles and face shields for protection of medical personnel at the outbreak of the COVID-19 pandemic. Unsurprisingly, almost all countries suffered from a critical supply shortage of goggles and face shields, as well as many other types of personal protective equipment (PPE), for a long period, owing to the lack of key medical material supplies and the inefficiency of existing fabrication methods arising from the need to avoid crowds during the outbreak of COVID-19. In this paper, we propose a novel combined shield design for eye and face protection that can be rapidly fabricated using three-dimensional printing technology. The designed prototype eye-face shield is accessible to the general public, offering more possibilities for yield improvement in PPE during emergent infectious disease events such as COVID-19.

5.
Phys Chem Chem Phys ; 23(2): 1750-1758, 2021 Jan 21.
Article in English | MEDLINE | ID: mdl-33427832

ABSTRACT

Molecular dynamics (MD) together with the first principles method (DFT) reveal that Na+ is capable of migrating three dimensionally in a Na2Mn2Si2O7 cathode material. Migration along the a-axis and c-axis have the same mechanism, that is, alternating between the Na1 and Na2 route with a similar local environment and distance. Long-distance hopping between two Na2 atoms or between Na1 and Na2 atoms is crucial for continuous migration along the b-axis. Also, the anti-site phenomenon is identified, and it facilitates the migration of the Na ions. Four intermediate phases are determined according to the formation energy curve and, as a result, the voltage profile is predicted accurately. The state of charge (SOC) dependency of the Na+ energy shows that the mobility of Na+ is highly inhibited in the fully discharged state. Upon the deintercalation of sodium ions, Na+ is activated immediately. A maximal DNa+ value of 3.6 × 10-9 cm2 s-1 and a low energy barrier of ca. 0.26 eV at the deintercalation level of x = 0.25 are observed. Because of the scarcity of Na+, DNa+ experiences a sharp decrease at the end of deintercalation. Despite the low level of Na+ mobility in the range of 0.25 < x < 1, Na2Mn2Si2O7 is still a potential cathode material for use in sodium ion batteries (SIBs).

6.
Article in English | WPRIM (Western Pacific) | ID: wpr-881050

ABSTRACT

Pesticides' overuse and misuse have been reported to induce ingredient variations in herbal medicine, which is now gaining attention in the medicinal field as a form of alternative medicine. To date, available studies on pesticide-induced ingredient variations of herbal medicine are limited only on a few compounds and remain most others unexamined. In this study, a plant metabolomics-based strategy was performed to systematically explore the effects of two frequently used insecticides on the comprehensive constituents of Lonicerae Japonicae Flos (LJF), the flower buds of Lonicera japonica Thunb. Field trials were designed on a cultivating plot of L. japonica with controls and treatments of imidacloprid (IMI) and compound flonicamid and acetamiprid (CFA). Unbiased metabolite profiling was conducted by ultra-high performance liquid chromatography/quadrupole-Orbitrap mass spectrometer. After data pretreatment by automatic extraction and screening, a data matrix of metabolite features was submitted for statistical analyses. Consequently, 29 metabolic markers, including chlorogenic acids, iridoids and organic acid-glucosides were obtained and characterized. The relative quantitative assay was subsequently performed to monitor their variations across flowering developments. This is the first study that systematically explored the insecticide-induced metabolite variations of LJF while taking into account the inherent variability of flowering development. The results were beneficial for holistic quality assessment of LJF and significant for guiding scientific use of pesticides in the large-scale cultivation.

7.
ACS Appl Mater Interfaces ; 11(25): 22429-22438, 2019 Jun 26.
Article in English | MEDLINE | ID: mdl-31140774

ABSTRACT

Based on the high theoretical capacity and relatively high safety voltage, niobium-based oxides are regarded as promising intercalation-type electrode materials for advanced lithium-ion batteries (LIBs). Here, ZrNb14O37 nanowires are fabricated via a facile electrospinning method, presenting a nanoparticle-in-nanowire architecture. As an anode for LIBs, the as-fabricated ZrNb14O37 nanowires maintain a capacity of 244.9 mA h g-1 at 100 mA g-1 and present excellent cycling capability (0.026% of capacity fading per cycle during 1000 cycles) as well as outstanding rate performance. In situ X-ray diffraction measurement is conducted to understand the fundamental reaction mechanism during the lithiation/delithiation process. The ex situ observations, including X-ray photoelectron spectroscopy and transmission electron microscopy, are further performed to provide more lines of evidence of the reaction mechanism. Moreover, the excellent electrochemical performance of the full cell constructed using ZrNb14O37 nanowires and LiCoO2 suggests that ZrNb14O37 nanowires are a promising anode material. This work sheds new light on understanding the lithium storage mechanism and may open new opportunities to develop new anode materials for LIBs.

8.
ACS Appl Mater Interfaces ; 11(9): 9136-9143, 2019 Mar 06.
Article in English | MEDLINE | ID: mdl-30763061

ABSTRACT

HTiNbO5 has been widely investigated in many fields because of its distinctive properties such as good redox activity, high photocatalytic activity, and environmental benignancy. Here, this work reports the synthesis of one-dimensional H0.92K0.08TiNbO5 nanowires via simple electrospinning followed by an ion-exchange reaction. The H0.92K0.08TiNbO5 nanowires consist of many small "lumps" with a uniform diameter distribution of around 150 nm. Used as an anode for lithium-ion batteries, H0.92K0.08TiNbO5 nanowires exhibit high capacity, fast electrochemical kinetics, and high performance of lithium-ion uptake. A capacity of 144.1 mA h g-1 can be carried by H0.92K0.08TiNbO5 nanowires at 0.5 C in the initial charge, and even after 150 cycles, the reversible capacity can remain at 123.7 mA h g-1 with an excellent capacity retention of 85.84%. For H0.92K0.08TiNbO5 nanowires, the diffusion coefficient of lithium ions is 1.97 × 10-11 cm2 s-1, which promotes the lithium-ion uptake effectively. The outstanding electrochemical performance is ascribed to its morphology and the formation of a stable phase during cycling. In addition, the in situ X-ray diffraction and ex situ transmission electron microscopy techniques are applied to reveal its lithium storage mechanism, which proves the structure stability and electrochemical reversibility, thus achieving high-performance lithium-ion uptake. All these advantages demonstrate that H0.92K0.08TiNbO5 nanowires can be a possible alternative anode material for rechargeable batteries.

9.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-801768

ABSTRACT

Objective: To observe the clinical efficacy of kidney tonifying and essence strengthening method in delaying physiological vascular aging. Method: Sixty-two subjects who completed the study were randomly divided into experimental group (31 cases) and control group (31 cases) with the matching research method. The experimental group was treated with kidney tonifying and essence strengthening recipe orally for 24 weeks, while the control group was not interfered with traditional Chinese medicine (TCM). Score of TCM syndrome in kidney deficiency syndrome, pulse wave velocity, intima-media thickness, plasma homocysteine level and serum superoxide dismutase level were evaluated before and after treatment. Result: Compared with before treatment period, the score of TCM syndrome in kidney deficiency syndrome, pulse wave velocity and plasma homocystenine level decreased, while the serum superoxide dismutase level increased in the experimental group after treatment (PPPPPConclusion: The kidney tonifying and essence strengthening method may delay the aging of physiological blood vessels caused by aging.

10.
ACS Appl Mater Interfaces ; 10(15): 12716-12721, 2018 Apr 18.
Article in English | MEDLINE | ID: mdl-29595243

ABSTRACT

In this work, garnet-framework Li3Nd3W2O12 as a novel insertion-type anode material has been prepared via a facile sol-gel method and examined as a lithium container for lithium ion batteries (LIBs). Li3Nd3W2O12 shows a charge capacity of 225 mA h g-1 at 50 mA g-1, and with the current density increasing up to 500 mA g-1, the charge capacity can still be maintained at 186 mA h g-1. After cycling at 500 mA g-1 for 500 cycles, Li3Nd3W2O12 retains about 85% of its first charge capacity changed from 190.2 to 161 mA h g-1. Furthermore, in situ X-ray diffraction technique is adopted for the understanding of the insertion/extraction mechanism of Li3Nd3W2O12. The full-cell configuration LiFePO4/Li3Nd3W2O12 is also assembled to evaluate the potential of Li3Nd3W2O12 for practical application. These results show that Li3Nd3W2O12 is such a promising anode material for LIBs with excellent electrochemical performance and stable structure.

11.
Sci Rep ; 7(1): 13156, 2017 10 13.
Article in English | MEDLINE | ID: mdl-29030615

ABSTRACT

The Gibbs free energy released during the mixing of river and sea water has been illustrated as a promising source of clean and renewable energy. Reverse electrodialysis (RED) is one major strategy to gain electrical power from this natural salinity, and recently by utilizing nanochannels a novel mode of this approach has shown improved power density and energy converting efficiency. In this work, we carry out an electrokinetic analysis of the work extracted from RED in the nanochannels. First, we outline the exclusion potential effect induced by the inhomogeneous distribution of extra-counterions along the channel axis. This effect is unique in nanochannel RED and how to optimize it for energy harvesting is the central topic of this work. We then discuss two important indexes of performance, which are the output power density and the energy converting efficiency, and their dependence on the nanochannel parameters such as channel material and geometry. In order to yield maximized output electrical power, we propose a device design by stepwise usage of the saline bias, and the lengths of the nanochannels are optimized to achieve the best trade-off between the input thermal power and the energy converting efficiency.

12.
ACS Appl Mater Interfaces ; 9(36): 30608-30616, 2017 Sep 13.
Article in English | MEDLINE | ID: mdl-28841286

ABSTRACT

VNb9O25 is a novel lithium storage material, which has not been systematically investigated so far. Via electrospinning technology, VNb9O25 samples with two different morphologies, pored nanoribbon and rodlike nanoparticles, are prepared in relatively low temperature and time-saving calcination conditions. It is found that the formation process of different morphologies depends on the control of self-aggregation of the precursor by using different sample collectors. Compared with rodlike VNb9O25 (RL-VNb9O25), pored nanoribbon VNb9O25 (PR-VNb9O25) can deliver a higher specific capacity, lower capacity loss, and better cyclability. Even cycled at 1000 mA g-1, the reversible capacity of 132.3 mAh g-1 is maintained by PR-VNb9O25 after 500 cycles, whereas RL-VNb9O25 only exhibits a capacity of 102.7 mAh g-1. The enhancement should be attributed to the pored nanoribbon structure with large specific surface area and shorter pathway for lithium ions transport. Furthermore, the lithium ions insertion/extraction process is verified from refinement results of in situ X-ray diffraction data, which is associated with a lithium occupation process in type III and VI cavities through tunnels I, II, and III. In addition, high structural stability and electrochemical reversibility are also demonstrated. All of these advantages suggest that PR-VNb9O25 is a promising anode material for lithium-ion batteries.

13.
Psychiatry Res ; 256: 71-78, 2017 10.
Article in English | MEDLINE | ID: mdl-28624675

ABSTRACT

The current study aimed to explore the association of cognitive emotion regulation, social support, resilience and acute stress responses in Chinese soldiers and to understand the multiple mediation effects of social support and resilience on the relationship between cognitive emotion regulation and acute stress responses. A total of 1477 male soldiers completed mental scales, including the cognitive emotion regulation questionnaire-Chinese version, the perceived social support scale, the Chinese version of the Connor-Davidson resilience scale, and the military acute stress scale. As hypothesized, physiological responses, psychological responses, and acute stress were associated with negative-focused cognitive emotion regulation, and negatively associated with positive-focused cognitive emotion regulation, social supports and resilience. Besides, positive-focused cognitive emotion regulation, social support, and resilience were significantly associated with one another, and negative-focused cognitive emotion regulation was negatively associated with social support. Regression analysis and bootstrap analysis showed that social support and resilience had partly mediating effects on negative strategies and acute stress, and fully mediating effects on positive strategies and acute stress. These results thus indicate that military acute stress is significantly associated with cognitive emotion regulation, social support, and resilience, and that social support and resilience have multiple mediation effects on the relationship between cognitive emotion regulation and acute stress responses.


Subject(s)
Cognition , Emotions , Military Personnel/psychology , Resilience, Psychological , Social Support , Stress Disorders, Traumatic, Acute/psychology , Adult , China/epidemiology , Cognition/physiology , Emotions/physiology , Humans , Male , Self Report , Stress Disorders, Traumatic, Acute/diagnosis , Stress Disorders, Traumatic, Acute/epidemiology
14.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-838376

ABSTRACT

Objective To investigate the relationships among resilience, perceived social support and acute stress reaction of naval soldiers. Methods Connor-Davidson resilience scale (CD RISC), perceived social support scale (PSSS) and the military acute stress scale (MASS) were used to investigate 1 348 naval soldiers. The relationships among the involved variables were analyzed by structural equation model. Results Perceived social support was positively correlated with resilience in the participants (P<0. 01). and both resilience and perceived social support were negatively correlated with the military acute stress reaction (P<0. 01); both of them could independently explain the variance of acute stress reaction of navy soldiers, in which strength (β = -0. 136, P<0. 01) and external family support (β = -0. 229. P< 0. 01) had significant negative predictive effects on military acute stress reaction. The mediating effect of resilience was significant between military acute stress reaction and perceived social support, accounting 16. 22% of the total effect. The model fitting was good: χ2/df = 27. 91/ 11 = 2. 537, P = 0.003; root mean square error of approximation (RMSEA) = 0. 032, comparative fit index (CFI) =0. 997 and goodness-of-fit index (GFI) = 0. 994. adjusted goodness of fit index (AGFI) =0.986, normed fit index (NFI) =0. 995, relative fit index (RFI) = 0. 986, incremental fitness index (IFI) = 0. 997 and Tucker-Lewis Index (TLI) = 0. 992. Conclusion Perceived social support has direct effect on acute stress reaction of navy soldiers, and it also has indirect influence on the acute stress reaction through the mediating effect of resilience.

15.
Nan Fang Yi Ke Da Xue Xue Bao ; 36(8): 1110-6, 2016 Aug 20.
Article in Chinese | MEDLINE | ID: mdl-27578582

ABSTRACT

OBJECTIVE: To detect the expression of miR-124 in colorectal carcinoma (CRC) cells and tissue specimens and analyze its association with the radiosensitivity of the cells. METHODS: The expression of miR-124 in CRC cell lines and tissues were detected using qRT-PCR. The effect of miR-124 in modulating cell radiosensitivity was assessed in CRC cells with miRNA-124 overexpression and miRNA-124 knockdown, and bioinformatics prediction and dual luciferase reporter system were employed to identify the direct target of miR-124. RESULTS: s miR-124 expression was down-regulated in CRC cell lines and tissues. CRC cells over-expressing miR-124 showed an obviously enhanced radiosensitivity, whereas miR-124 knockdown resulted in a reduced radiosensitivity of the cells. Bioinformatics prediction and dual luciferase reporter system verified PRRX1 as a direct target of miR-124, which regulated the radiosensitivity of CRC cells by directly inhibiting PRRX1. CONCLUSION: miR-124 can enhance the radiosensitivity of CRC cells by directly targeting PRRX1, which provides a target for improving the therapeutic effect of radiotherapy of CRC.


Subject(s)
Colorectal Neoplasms/pathology , Gene Expression Regulation, Neoplastic , Homeodomain Proteins/metabolism , MicroRNAs/metabolism , Radiation Tolerance , Cell Line, Tumor , Colorectal Neoplasms/radiotherapy , Down-Regulation , Homeodomain Proteins/genetics , Humans , Luciferases , MicroRNAs/genetics
16.
ACS Appl Mater Interfaces ; 8(16): 10302-14, 2016 04 27.
Article in English | MEDLINE | ID: mdl-27052633

ABSTRACT

Via Li(+), Cu(2+), Y(3+), Ce(4+), and Nb(5+) dopings, a series of Na-site-substituted Na1.9M0.1Li2Ti6O14 are prepared and evaluated as lithium storage host materials. Structural and electrochemical analyses suggest that Na-site substitution by high-valent metal ions can effectively enhance the ionic and electronic conductivities of Na2Li2Ti6O14. As a result, Cu(2+)-, Y(3+)-, Ce(4+)-, and Nb(5+)-doped samples reveal better electrochemical performance than bare Na2Li2Ti6O14, especially for Na1.9Nb0.1Li2Ti6O14, which can deliver the highest reversible charge capacity of 259.4 mAh g(-1) at 100 mA g(-1) among all samples. Even when cycled at higher rates, Na1.9Nb0.1Li2Ti6O14 still can maintain excellent lithium storage capability with the reversible charge capacities of 242.9 mAh g(-1) at 700 mA g(-1), 216.4 mAh g(-1) at 900 mA g(-1), and 190.5 mAh g(-1) at 1100 mA g(-1). In addition, ex situ and in situ observations demonstrate that the zero-strain characteristic should also be responsible for the outstanding lithium storage capability of Na1.9Nb0.1Li2Ti6O14. All of this evidence indicates that Na1.9Nb0.1Li2Ti6O14 is a high-performance anode material for rechargeable lithium ion batteries.

17.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-286838

ABSTRACT

<p><b>OBJECTIVE</b>To detect the expression of miR-124 in colorectal carcinoma (CRC) cells and tissue specimens and analyze its association with the radiosensitivity of the cells.</p><p><b>METHODS</b>The expression of miR-124 in CRC cell lines and tissues were detected using qRT-PCR. The effect of miR-124 in modulating cell radiosensitivity was assessed in CRC cells with miRNA-124 overexpression and miRNA-124 knockdown, and bioinformatics prediction and dual luciferase reporter system were employed to identify the direct target of miR-124.</p><p><b>RESULTS</b>s miR-124 expression was down-regulated in CRC cell lines and tissues. CRC cells over-expressing miR-124 showed an obviously enhanced radiosensitivity, whereas miR-124 knockdown resulted in a reduced radiosensitivity of the cells. Bioinformatics prediction and dual luciferase reporter system verified PRRX1 as a direct target of miR-124, which regulated the radiosensitivity of CRC cells by directly inhibiting PRRX1.</p><p><b>CONCLUSION</b>miR-124 can enhance the radiosensitivity of CRC cells by directly targeting PRRX1, which provides a target for improving the therapeutic effect of radiotherapy of CRC.</p>


Subject(s)
Humans , Cell Line, Tumor , Colorectal Neoplasms , Pathology , Radiotherapy , Down-Regulation , Gene Expression Regulation, Neoplastic , Homeodomain Proteins , Genetics , Metabolism , Luciferases , MicroRNAs , Genetics , Metabolism , Radiation Tolerance
18.
Cytokine ; 72(1): 31-5, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25569374

ABSTRACT

BACKGROUND AND AIMS: It is suggested that regulatory immune cells play a critical role in cancer cell growth by facilitating cancer cells to escape from the immune surveillance. The generation of the immune regulatory cells in cancer has not been fully understood yet. This study aims to investigate the role of the hepatoma-derived growth factor (HDGF) in the generation of regulatory T cells (Treg). METHODS: CCL-9.1 cells (A mouse hepatoma cell line), were cultured. The expression of HDGF in CCL-9.1 cells was assessed by quantitative RT-PCR and Western blotting. The generation of Foxp3(+) T cells was assessed by cell culture and flow cytometry. The immune suppressor function of the Foxp3(+) T cells on CD8(+) T cell activities was assessed by the carboxyfluorescein succinimidyl ester (CFSE)-dilution assay and enzyme-linked immunosorbent assay. RESULTS: The results showed that exposure to PolyIC markedly increased the expression of HDGF in CCL-9.1 cells. Coculture of CCL-9.1 cells and CD4(+) CD25(-) T cells in the presence of PolyIC generated the Forkhead box protein (Foxp)3(+) T cells. The exposure to HDGF increased the expression of Foxp3 and decreased the expression of GATA3 in CD4(+) T cells. After activation, the Foxp3(+) T cells suppressed the CD8(+) T cell proliferation and the release of the cytotoxic cytokines. CONCLUSIONS: Liver cancer cell-derived HDGF can induce Foxp3(+) T cells; the latter has the immune suppressor functions on CD8(+) T cell activities.


Subject(s)
Carcinoma, Hepatocellular/metabolism , Intercellular Signaling Peptides and Proteins/physiology , T-Lymphocytes, Cytotoxic/immunology , T-Lymphocytes, Regulatory/immunology , Animals , Blotting, Western , Cell Line, Tumor , Coculture Techniques , Enzyme-Linked Immunosorbent Assay , Flow Cytometry , Forkhead Transcription Factors/metabolism , Intercellular Signaling Peptides and Proteins/isolation & purification , Liver Neoplasms/metabolism , Lymphocyte Activation , Mice , Mice, Inbred BALB C , Poly I-C/pharmacology , Real-Time Polymerase Chain Reaction , T-Lymphocytes, Regulatory/physiology
19.
Acta Pharmaceutica Sinica ; (12): 277-81, 2014.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-448734

ABSTRACT

This paper aims to establish a method for the determination of sulfur dioxide in sulfur fumigation Chinese herbs. Sample powder and hydrochloric acid solution were isolated by paraffin layer in order to avoid early reactions, with the generation of sulfur dioxide, headspace with airtight needle was used to transfer sulfur dioxide into gas chromatograph, and detected with thermal conductivity detector. The analytical performance was demonstrated by the analysis of 12 herbs, spiked at four concentration levels. In general, the recoveries ranging from 70% to 110%, with relative standard deviations (RSDs) within 15%, were obtained. The limit of detection (LOD) was below 10 mg x kg(-1). Standard addition can be used for low recovery samples. The method is simple, less time-consuming, specific and sensitive. Methods comparison revealed that gas chromatography is better than traditional titration in terms of method operability, accuracy and specificity, showing good application value.

20.
Acta Pharmaceutica Sinica ; (12): 277-281, 2014.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-297979

ABSTRACT

This paper aims to establish a method for the determination of sulfur dioxide in sulfur fumigation Chinese herbs. Sample powder and hydrochloric acid solution were isolated by paraffin layer in order to avoid early reactions, with the generation of sulfur dioxide, headspace with airtight needle was used to transfer sulfur dioxide into gas chromatograph, and detected with thermal conductivity detector. The analytical performance was demonstrated by the analysis of 12 herbs, spiked at four concentration levels. In general, the recoveries ranging from 70% to 110%, with relative standard deviations (RSDs) within 15%, were obtained. The limit of detection (LOD) was below 10 mg x kg(-1). Standard addition can be used for low recovery samples. The method is simple, less time-consuming, specific and sensitive. Methods comparison revealed that gas chromatography is better than traditional titration in terms of method operability, accuracy and specificity, showing good application value.


Subject(s)
Chromatography, Gas , Methods , Fumigation , Limit of Detection , Plants, Medicinal , Chemistry , Sulfur , Chemistry , Sulfur Dioxide
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