A cationic gene delivery vector, guanidinylated disulfide-containing poly(amido amine)(CARCBA), was synthesized by Michael addition reaction between N,N′-cystaminebisacrylamide(CBA) and guanidine hydrochloride(CAR). ...A cationic gene delivery vector, guanidinylated disulfide-containing poly(amido amine)(CARCBA), was synthesized by Michael addition reaction between N,N′-cystaminebisacrylamide(CBA) and guanidine hydrochloride(CAR). Gel permeation chromatography(GPC) was used to evaluate the molecular weight of synthesized CAR-CBA. Polyethyleneimine(PEI) with molecular weight of 25 kDa was adopted as a reference, and polyethylene glycols(PEG) with different molecular weights were used to establish a standard curve for determining the molecular weight of CAR-CBA. The effects of two critical factors, namely columns and eluents,on the molecular weight measurement of CAR-CBA were investigated to optimize the GPC quantitative method. The results showed that Ultrahydrogel columns(120, 250) and HAc–NaAc(0.5 M, pH 4.5) buffer solution were the optimal column and GPC eluent, respectively.The molecular weight of the synthesized CAR-CBA was analyzed by the optimized GPC method and determined to be 24.66 kDa.展开更多
The measurement of 23 organochlorine, organophosphorus, and pyrethroid pesticides in typical traditional Chinese medicine (TCM), flos lonicerae, was made using gel permeation chromatography (GPC) purification and gas ...The measurement of 23 organochlorine, organophosphorus, and pyrethroid pesticides in typical traditional Chinese medicine (TCM), flos lonicerae, was made using gel permeation chromatography (GPC) purification and gas chroma- tography-mass spectrometry (GC-MS) detection. The pesticides were extracted with ultrasonic device and 5.0 mL mixture of ethyl acetate and cyclohexane (1:1, v/v). Coextractants from sample matrices which may have interfere to the qualitative and quantitative analysis, such as pigments, were removed using GPC purification. Simultaneous full scan and selective ion monitor (scan/SIM) mode for GC-MS was used for qualitative and quantitative analysis, which pro- vided retention time and characteristic fragments ratio for each pesticide so as to positively identify each analyte. Rela- tive standard deviations (RSDs) were within 7.7% (5.0 - 22.5 μg/kg, n = 3). The recoveries of pesticide standards at the spiked concentration of 5.0 - 22.5 μg/kg were between 87.1% and 110.9%. Limits of detection (LODs) for the analytes were 0.16 - 3.2 μg/kg, which could meet the demand of routine analysis and TCM quality control.展开更多
A highly sensitive method was developed for the simultaneous determination of 8 steroid hormones in high-fat fish tissues using ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).The 8 s...A highly sensitive method was developed for the simultaneous determination of 8 steroid hormones in high-fat fish tissues using ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).The 8 steroid hormones were extracted from the tissues with diethyl ether.Differing from other common purification methods,the extract solutions were cleaned by gel permeation chromatography(GPC) using ethyl acetate-cyclohexane solution(1:1,v/v) as the mobile phase.The separation of target compounds was carried out by a BEH C18 column and a gradient elution consisting of acetonitrile and 0.2% aqueous formic acid(v/v).The compounds were detected under the multiple reaction monitoring(MRM) mode and quantified with external standard method.This method was validated with respect to linearity,specificity,accuracy and precision.A linearity with correlation coefficient larger than 0.995 was achieved in the range of 0.5 to 50 ng m L^(-1).The average recoveries at the spiked levels of 1.0,5.0,and 10.0 μg kg^(–1) varied between 81.7% and 90.8%,with the relative standard deviations(n=5) ranged from 3.50% to 10.0%.The limit of quantification(LOQ) for 8 steroid hormones ranged from 0.2 to 1.5 μg kg^(-1).It was concluded that this method can be successfully applied for the determination of 8 steroid hormones in complicated matrices including high-fat fish tissues.展开更多
Car headlight plastic as a kind of evidence often can be seen in traffic accidents and some other cases.We tested 20 brands of car headlight plastic using gel chromatography.The data were processed using the Statistic...Car headlight plastic as a kind of evidence often can be seen in traffic accidents and some other cases.We tested 20 brands of car headlight plastic using gel chromatography.The data were processed using the Statistical Package for the Social Sciences(SPSS)one‑way analysis of variance(ANOVA)and the discrimination rate was 97.14%.This indicated that we could discriminate between different headlights by the molecular weight of their headlight plastic.Gel permeation chromatography is an effective method of discriminating between headlights,particularly in the case of a traffic accident.展开更多
Objective: To find a more effective method of topical transdermal delivery of curcumin. Methods: We prepared curcumin carbopol(CRB) 974P and hydroxypropylcellulose(HPC) gel formulations containing menthol or Azone as ...Objective: To find a more effective method of topical transdermal delivery of curcumin. Methods: We prepared curcumin carbopol(CRB) 974P and hydroxypropylcellulose(HPC) gel formulations containing menthol or Azone as permeation enhancers. In this study, negative mode electrospray ionization and a triple quadruple LC/MS/MS instrument operated in multiple reaction mode was used for curcumin detection. The assay was linear over a concentration range of 10 ng/mL to 400 ng/mL for curcumin(average R2= 0.997 2). Excised nude mouse dorsal side skin was used in an in vitro skin permeation study performed using the method of Franz. Results: Our results showed that all of the topical gel formulations we developed were free from skin irritation. The percutaneous flux and enhancement ratio of curcumin across nude mouse epidermis were enhanced markedly by the addition of menthol or Azone to both types of gel formulations. We found that the HPC gels containing quantities of Azone showed an enhanced permeation effect as compared to gels containing menthol. In the case of HPC gels containing Azone, the increase in permeability was significant(P<0.05) as compared to the gels containing menthol. Conclusion: Azone shows a significantly more remarkable permeation effect than menthol. As such, this novel delivery strategy offers significant promise and is worthy of further exploration in attempts to enhance the medicinal application of curcumin.展开更多
Deoxynivalenol(DON) is a type B trichothecenes mycotoxin produced by several Fusarium species, often found in foodstuffs for humans and animals. DON is in great demand for the toxicological researches both in vivo and...Deoxynivalenol(DON) is a type B trichothecenes mycotoxin produced by several Fusarium species, often found in foodstuffs for humans and animals. DON is in great demand for the toxicological researches both in vivo and in vitro. In this work, wheat culture was inoculated with a Fusarium graminearum PH-1 strain for DON production. The solvent system for crude extraction was acetonitrile-water(84:16, v/v). A simple two-step silica gel column chromatography was employed to separate the DON mycotoxin from wheat culture, combined with preparative high performance liquid chromatography(preparative HPLC) to purify the compound. The solvent system for the second silica gel column chromatography was methylene chloride-methanol(17:1, v/v), which provided a good elution effect selected on thin layer chromatography(TLC). The target compound was identified by HPLC, and the chemical structure was confirmed by mass spectrometry(MS) and ~1H and ^(13)C nuclear magnetic resonance(NMR) spectroscopy. A total of 433 mg of purified DON was obtained from 1 kg of wheat culture, with a purity of 99.01%. The study had provided an easy-operating and cost-effective method to isolate an expensive compound in a simple way.展开更多
Ten fractionated samples of Chinese lacquer polysaccharide in aqueous 0.1M NaC1 solution were studied by aqueous-phase gel permeation chromatography (GPC). The universal calibration, broad MWD calibration and correcte...Ten fractionated samples of Chinese lacquer polysaccharide in aqueous 0.1M NaC1 solution were studied by aqueous-phase gel permeation chromatography (GPC). The universal calibration, broad MWD calibration and corrected column dispersion were adopted to the analysis of GPC chromatograms of the polysaccharide. The molecular weights M_w, M_n and polydispersity index M_w/M_n obtained from GPC are in good agreement with the results of light scattering and membrane osmometry. It is verified that the universal calibration concept is applicable to the lacquer polysaccharide having a number of side chains.展开更多
[Objectives] To develop a method for separation and purification of acetophenones from Cynanchum bengei Decne root bark by combination of silica gel and high-speed counter-current chromatography( HSCCC). [Methods]The ...[Objectives] To develop a method for separation and purification of acetophenones from Cynanchum bengei Decne root bark by combination of silica gel and high-speed counter-current chromatography( HSCCC). [Methods]The crude extract of Cynanchum bengei Decne root bark was separated by silica gel column chromatography,and parts A and B containing acetophenones were obtained. Then,parts A and B were separated by HSCCC with a two-phase solvent system composed of petroleum ether-ethyl acetate-methanol-water( 4∶ 6∶ 4. 5∶ 5. 5 and4∶ 6 ∶ 3 ∶ 7, V/V), respectively. [Results] From 260 mg of part A, four compounds with p-dihydroxybenzene 3. 9 mg(Ⅰ),4-hydroxyacetophenone 17. 1 mg( Ⅱ),2,5-di-hydroxyacetophenone 13. 3 mg(Ⅲ) and 2,4-dihydroxyaceto-phenone 21. 0 mg(Ⅳ) were obtained. And from 300 mg of part B,136 mg of Radix Cynanchi Bungei benzophenone(Ⅴ) was obtained. The purity of compounds determined by HPLC was 97. 0%,96. 6%,99. 2%,99. 7%,99. 5%,respectively. [Conclusions] The established method is simple and efficient. It can be used for separation of acetophenones from Cynanchum bengei Decne root bark and has better practical value,which could provide a reference basis for development and utilization of Cynanchum bengei Decne root bark.展开更多
Conventional plasticizers deteriorate mechanical and viscoelastic properties of the propellants due to their migration upon aging and long-term storage,which affects reliability and safety properties during exploitati...Conventional plasticizers deteriorate mechanical and viscoelastic properties of the propellants due to their migration upon aging and long-term storage,which affects reliability and safety properties during exploitation.To address this issue,conventional plasticizer,dioctyl adipate(DOA),is replaced by reactive one,castor oil(CO).In addition,three different types of HTPB were used to obtain propellants with designed viscoelastic and mechanical properties.The CO increased propellants viscosity,without a significant impact on the propellant processability,regardless to the type of prepolymer.Conversely,mechanical properties were different depending on the type of resin,which were further analyzed by gel permeation chromatography(GPC).Addition of CO formed a denser polymer network and shifted T_(g) to higher values,compared to the compositions with DOA.The tensile strength of CO-containing propellants was lower at +20℃ and +50℃ compared to the reference compositions,while the strain at maximum load and strain at break were significantly increased with pronounced plastic deformation,especially for samples at -30℃.The inclusion of CO in the propellants composition gives more room for adjusting a wide range of mechanical properties.展开更多
基金the National Natural Science Foundation of China for financial support(No.81373335)
文摘A cationic gene delivery vector, guanidinylated disulfide-containing poly(amido amine)(CARCBA), was synthesized by Michael addition reaction between N,N′-cystaminebisacrylamide(CBA) and guanidine hydrochloride(CAR). Gel permeation chromatography(GPC) was used to evaluate the molecular weight of synthesized CAR-CBA. Polyethyleneimine(PEI) with molecular weight of 25 kDa was adopted as a reference, and polyethylene glycols(PEG) with different molecular weights were used to establish a standard curve for determining the molecular weight of CAR-CBA. The effects of two critical factors, namely columns and eluents,on the molecular weight measurement of CAR-CBA were investigated to optimize the GPC quantitative method. The results showed that Ultrahydrogel columns(120, 250) and HAc–NaAc(0.5 M, pH 4.5) buffer solution were the optimal column and GPC eluent, respectively.The molecular weight of the synthesized CAR-CBA was analyzed by the optimized GPC method and determined to be 24.66 kDa.
文摘The measurement of 23 organochlorine, organophosphorus, and pyrethroid pesticides in typical traditional Chinese medicine (TCM), flos lonicerae, was made using gel permeation chromatography (GPC) purification and gas chroma- tography-mass spectrometry (GC-MS) detection. The pesticides were extracted with ultrasonic device and 5.0 mL mixture of ethyl acetate and cyclohexane (1:1, v/v). Coextractants from sample matrices which may have interfere to the qualitative and quantitative analysis, such as pigments, were removed using GPC purification. Simultaneous full scan and selective ion monitor (scan/SIM) mode for GC-MS was used for qualitative and quantitative analysis, which pro- vided retention time and characteristic fragments ratio for each pesticide so as to positively identify each analyte. Rela- tive standard deviations (RSDs) were within 7.7% (5.0 - 22.5 μg/kg, n = 3). The recoveries of pesticide standards at the spiked concentration of 5.0 - 22.5 μg/kg were between 87.1% and 110.9%. Limits of detection (LODs) for the analytes were 0.16 - 3.2 μg/kg, which could meet the demand of routine analysis and TCM quality control.
基金supported by the Natural Science Foundation of Zhejiang Province,China(No.LY17C200009)the Foundation of Zhejiang Educational Committee(No.Y201328477)
文摘A highly sensitive method was developed for the simultaneous determination of 8 steroid hormones in high-fat fish tissues using ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).The 8 steroid hormones were extracted from the tissues with diethyl ether.Differing from other common purification methods,the extract solutions were cleaned by gel permeation chromatography(GPC) using ethyl acetate-cyclohexane solution(1:1,v/v) as the mobile phase.The separation of target compounds was carried out by a BEH C18 column and a gradient elution consisting of acetonitrile and 0.2% aqueous formic acid(v/v).The compounds were detected under the multiple reaction monitoring(MRM) mode and quantified with external standard method.This method was validated with respect to linearity,specificity,accuracy and precision.A linearity with correlation coefficient larger than 0.995 was achieved in the range of 0.5 to 50 ng m L^(-1).The average recoveries at the spiked levels of 1.0,5.0,and 10.0 μg kg^(–1) varied between 81.7% and 90.8%,with the relative standard deviations(n=5) ranged from 3.50% to 10.0%.The limit of quantification(LOQ) for 8 steroid hormones ranged from 0.2 to 1.5 μg kg^(-1).It was concluded that this method can be successfully applied for the determination of 8 steroid hormones in complicated matrices including high-fat fish tissues.
文摘Car headlight plastic as a kind of evidence often can be seen in traffic accidents and some other cases.We tested 20 brands of car headlight plastic using gel chromatography.The data were processed using the Statistical Package for the Social Sciences(SPSS)one‑way analysis of variance(ANOVA)and the discrimination rate was 97.14%.This indicated that we could discriminate between different headlights by the molecular weight of their headlight plastic.Gel permeation chromatography is an effective method of discriminating between headlights,particularly in the case of a traffic accident.
基金Supported by the National Natural Science Foundation of China(81173130)
文摘Objective: To find a more effective method of topical transdermal delivery of curcumin. Methods: We prepared curcumin carbopol(CRB) 974P and hydroxypropylcellulose(HPC) gel formulations containing menthol or Azone as permeation enhancers. In this study, negative mode electrospray ionization and a triple quadruple LC/MS/MS instrument operated in multiple reaction mode was used for curcumin detection. The assay was linear over a concentration range of 10 ng/mL to 400 ng/mL for curcumin(average R2= 0.997 2). Excised nude mouse dorsal side skin was used in an in vitro skin permeation study performed using the method of Franz. Results: Our results showed that all of the topical gel formulations we developed were free from skin irritation. The percutaneous flux and enhancement ratio of curcumin across nude mouse epidermis were enhanced markedly by the addition of menthol or Azone to both types of gel formulations. We found that the HPC gels containing quantities of Azone showed an enhanced permeation effect as compared to gels containing menthol. In the case of HPC gels containing Azone, the increase in permeability was significant(P<0.05) as compared to the gels containing menthol. Conclusion: Azone shows a significantly more remarkable permeation effect than menthol. As such, this novel delivery strategy offers significant promise and is worthy of further exploration in attempts to enhance the medicinal application of curcumin.
基金supported by the National Natural Science Foundation of China (31402268)the Natural Science Foundation of Jiangsu Province of China (BK20140691)+1 种基金Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), ChinaThe Introduction of International Advanced Agricultural Science and Technology Project from the Ministry of Agriculture of China (2012-Z22)
文摘Deoxynivalenol(DON) is a type B trichothecenes mycotoxin produced by several Fusarium species, often found in foodstuffs for humans and animals. DON is in great demand for the toxicological researches both in vivo and in vitro. In this work, wheat culture was inoculated with a Fusarium graminearum PH-1 strain for DON production. The solvent system for crude extraction was acetonitrile-water(84:16, v/v). A simple two-step silica gel column chromatography was employed to separate the DON mycotoxin from wheat culture, combined with preparative high performance liquid chromatography(preparative HPLC) to purify the compound. The solvent system for the second silica gel column chromatography was methylene chloride-methanol(17:1, v/v), which provided a good elution effect selected on thin layer chromatography(TLC). The target compound was identified by HPLC, and the chemical structure was confirmed by mass spectrometry(MS) and ~1H and ^(13)C nuclear magnetic resonance(NMR) spectroscopy. A total of 433 mg of purified DON was obtained from 1 kg of wheat culture, with a purity of 99.01%. The study had provided an easy-operating and cost-effective method to isolate an expensive compound in a simple way.
文摘Ten fractionated samples of Chinese lacquer polysaccharide in aqueous 0.1M NaC1 solution were studied by aqueous-phase gel permeation chromatography (GPC). The universal calibration, broad MWD calibration and corrected column dispersion were adopted to the analysis of GPC chromatograms of the polysaccharide. The molecular weights M_w, M_n and polydispersity index M_w/M_n obtained from GPC are in good agreement with the results of light scattering and membrane osmometry. It is verified that the universal calibration concept is applicable to the lacquer polysaccharide having a number of side chains.
基金Supported by National Natural Science Foundation Item of 2014(81373941)Shandong Natural Science Foundation Item of 2012(ZR2012HM047)+1 种基金Science and Technology Development Plan Item of Shandong(2014G2X219003)Major Project of the State Administration of Traditional Chinese Medicine(201407002)
文摘[Objectives] To develop a method for separation and purification of acetophenones from Cynanchum bengei Decne root bark by combination of silica gel and high-speed counter-current chromatography( HSCCC). [Methods]The crude extract of Cynanchum bengei Decne root bark was separated by silica gel column chromatography,and parts A and B containing acetophenones were obtained. Then,parts A and B were separated by HSCCC with a two-phase solvent system composed of petroleum ether-ethyl acetate-methanol-water( 4∶ 6∶ 4. 5∶ 5. 5 and4∶ 6 ∶ 3 ∶ 7, V/V), respectively. [Results] From 260 mg of part A, four compounds with p-dihydroxybenzene 3. 9 mg(Ⅰ),4-hydroxyacetophenone 17. 1 mg( Ⅱ),2,5-di-hydroxyacetophenone 13. 3 mg(Ⅲ) and 2,4-dihydroxyaceto-phenone 21. 0 mg(Ⅳ) were obtained. And from 300 mg of part B,136 mg of Radix Cynanchi Bungei benzophenone(Ⅴ) was obtained. The purity of compounds determined by HPLC was 97. 0%,96. 6%,99. 2%,99. 7%,99. 5%,respectively. [Conclusions] The established method is simple and efficient. It can be used for separation of acetophenones from Cynanchum bengei Decne root bark and has better practical value,which could provide a reference basis for development and utilization of Cynanchum bengei Decne root bark.
基金the support of this research from the Serbian Ministry of Education,Science and Technological Development(Grant No.451-03-68/2023-14/200325)Ministry of Defense(Grant No.VA-TT/1/22-24)。
文摘Conventional plasticizers deteriorate mechanical and viscoelastic properties of the propellants due to their migration upon aging and long-term storage,which affects reliability and safety properties during exploitation.To address this issue,conventional plasticizer,dioctyl adipate(DOA),is replaced by reactive one,castor oil(CO).In addition,three different types of HTPB were used to obtain propellants with designed viscoelastic and mechanical properties.The CO increased propellants viscosity,without a significant impact on the propellant processability,regardless to the type of prepolymer.Conversely,mechanical properties were different depending on the type of resin,which were further analyzed by gel permeation chromatography(GPC).Addition of CO formed a denser polymer network and shifted T_(g) to higher values,compared to the compositions with DOA.The tensile strength of CO-containing propellants was lower at +20℃ and +50℃ compared to the reference compositions,while the strain at maximum load and strain at break were significantly increased with pronounced plastic deformation,especially for samples at -30℃.The inclusion of CO in the propellants composition gives more room for adjusting a wide range of mechanical properties.
