A transformation of naphthalene-based coalescenced mesophase pitch(NMP)to mesophase microbeads was achieved by heating a mixture of NMP and fullerene(C_(60)).This is different from the conventional process of the liqu...A transformation of naphthalene-based coalescenced mesophase pitch(NMP)to mesophase microbeads was achieved by heating a mixture of NMP and fullerene(C_(60)).This is different from the conventional process of the liquid-phase carbonization of isotropic pitch to the emergence of carbon microbeads in the matrix and finally their growth to form a 100%anisotropic bulk meso-phase,but rather a reverse transformation.The effects of C_(60) loading and reaction temperature on the morphological transformation of mesophase were investigated by polarizing optical and scanning electron microscopies.The physical changes in the NMP induced by C_(60) were characterized by thermogravimetric analysis,Fourier transform infrared spectroscopy,X-ray diffractometry and Raman spectroscopy.The results show that the coalesced NMP can be converted to a spherical type at 300-320℃ with the addition of 5%C_(60),and the size of the mesophase microbeads increases with increasing temperature.Furthermore,a model is established to ex-plain the unique induction effect of C_(60) in the transformation process.This work makes the morphological transformation of MP con-trollable,and provides a new idea for the understanding and research of mesophase pitch.展开更多
Aim In the present study a RP-HPLC method was developed and validated toinvestigate the stability of baicalin aqueous solution. Methods The influences of temperature and pHon the stability of baicalin aqueous solution...Aim In the present study a RP-HPLC method was developed and validated toinvestigate the stability of baicalin aqueous solution. Methods The influences of temperature and pHon the stability of baicalin aqueous solution were investigated by classic homoiothermicacceleration test, and the pH for the most stable solution was determined. Results The time whenbaicalin suffered 10% loss was found to be 18.1 h, and the degradation activation energy of baicalinwas 79.1 kJ·moL^(-1) . The pH at which baicalin is most stable is 4.28. Conclusion The temperatureshould be kept at a lower level and the pH should be adjusted to near that for the most stablesolution in the production of baicalin preparations.展开更多
[Objective] This study was conducted to develop a system for simultaneous determination of imidacloprid, diflubenzuron, thiabendazole and carbendazim in fruit juice by HPLC. [Method] Using acetonitrile as the extracti...[Objective] This study was conducted to develop a system for simultaneous determination of imidacloprid, diflubenzuron, thiabendazole and carbendazim in fruit juice by HPLC. [Method] Using acetonitrile as the extraction solvent, the pesticides in fruit juice were purified through a NH2 solid phase extraction (SPE) cartridge, then detected by HPLC. [Result] There was a good linear relationship between the peak area and the concentrations of imidacloprid, diflubenzuron, thiabendazole and carbendazim in a range of 0.05-5.0 μg/ml, and the linear correlation coefficient varied in a range of 0.999 0-0.999 8; the limit of detection for imidacloprid, diflubenzuron, thiabendazole and carbendazim was 0.003, 0.005, 0.003 and 0.007 mg/kg, respectively. The recovery rate of imidacloprid, diflubenzuron, thiabendazole and carbendazim standards added at three levels (0.1, 0.5 and 1.0 mg/kg) ranged from 82% to 107%, with RSD less than 4.5%. [Conclusion] The sensitivity, accuracy and precision of this method were able to meet the requirements for pesticide residue analysis.展开更多
[Objective] The aim was to evaluate the uncertainty of determining aspartame in beverage by high performance liquid chromatography ( HPLC). [Method] The content of aspartame in beverage was determined by HPLC, then ...[Objective] The aim was to evaluate the uncertainty of determining aspartame in beverage by high performance liquid chromatography ( HPLC). [Method] The content of aspartame in beverage was determined by HPLC, then the source of uncertainty in the whole determination process was analyzed, and each component of uncertainty was evaluated and combined. [ Result] Through 6 repeated determinations by the method in GB/T 22254-2008 "Determination of Aspartame in Food", the average content of aspartame in beverage was (0.806 ±0.038) g/kg, and k =2. The main sources of uncertainty to affect the process were the sample weighting process, the preparation process of standard solution introduced by sample constant volume and the uncertainty introduced by fitting standard curve. ①The uncertainty of standard work-solution. The combined uncertainty of standard work-solution was 0.013 9, among them the uncertainty introduced by standard sample purity was 0.005 8, the standard uncertainty introduced by standard material weighting was 1.49 ×10^4, the relative uncertainty introduced by glass apparatus calibration in the preparation process of aspartame standard reserving solution was 0. 007 88, and the uncertainty introduced by glass apparatus calibration in the preparation process of standard work-solution was 0. 009 9. ②The uncertainty introduced by the preparation process of sample specimen. Among them the relative standard uncertainty introduced by sample weighting process was 0. 009, and the uncertainty introduced by sample constant volume was 0.000 78. ③The uncertainty introduced by the fitting process of standard curve. Among them the relative uncertainty of curve fitting was 0.002 46, the uncertainty introduced by the determined results of aspartame was 0.017 0, the total combined standard uncertainty was 0.023 9, and the expanded standard uncertainty was 0.019. [ Conclusion] The uncertainty components of standard solution, standard curve and repeatability are the main sources of uncertainty, while those of sample weighting and sample constant volume account for little proportion.展开更多
ObjectiveThis study aimed to investigate the biodegradation effect and biodegradation mechanism of aniline aerofloat wastewater. MethodSmall-scale processing of simulated aniline aerofloat wastewater was carried out w...ObjectiveThis study aimed to investigate the biodegradation effect and biodegradation mechanism of aniline aerofloat wastewater. MethodSmall-scale processing of simulated aniline aerofloat wastewater was carried out with SBR (Sequencing Batch Reactor) system; intermediate products in the process were analyzed using high-performance liquid chromatography. ResultAccording to the experimental results, the small-scale process was basically stably operated after 40 days of activation and regulation, leading to relatively ideal degradation effect on aniline aerofloat, the COD removal efficiency reached 64.3% , degradation rate of aniline aerofloat reached 93.4%, which could be applied in the treatment of mine flotation wastewater containing such pollutant. During the degradation process, pH increased from 5.83 to 6.60 and then dropped to 6.17, which might be caused by the thiocyanate ions and aniline generated in the degradation process. Aniline aerofloat mainly produced two preliminary products during the biodegradation process: aniline and a substance that was difficult to be biodegraded under aerobic conditions, which was the main reason for the relatively high COD value in effluent. Furthermore, aniline was eventually biodegraded. ConclusionThis study provided basis for the development of biological treatment of flotation wastewater in China and showed great significance for the improvement of ecological environment around the mines.展开更多
Aim To develop and determine pinoresinol diglucopyranoside in Qing'e Pill, atraditional Chinese compound preparation containing Eucommia ulmoides Oliv. as the principal drug,by a reverse-phase high-performance liq...Aim To develop and determine pinoresinol diglucopyranoside in Qing'e Pill, atraditional Chinese compound preparation containing Eucommia ulmoides Oliv. as the principal drug,by a reverse-phase high-performance liquid chromatographic method (RP-HPLC) . Methods The extract ofQing'e Pill was refluxed with 75% ethanol, purified on an AB-8 macroporous adsorption resin columnand then injected into HPLC system. The HPLC assay was performed on an ODS analytical column with amixture of methanol-acetonitrile-water (24:3:78, V/V/V) as the mobile phase at a flow-rate of 1.0mL·min^(-1), and a UV detector set at 227 nm. Results Good linearity between peak area andconcentration was found in the range of 5.5 - 170 μg·mL^(-1) for pinoresinol diglucopyranoside ( r> 0.9998) . The average recovery was 99.3%. The intra-day assay RSD and the inter-day assay RSDwere 1.3% and 2.8%, respectively (n = 5). The content of pinoresinol diglucopyranoside in Qing'ePill was determined to be 0.446 +- 0.012 mg·g^(-1) (n = 10). Conclusion The RP-HPLC method wasproved to be sensitive, specific, accurate and precise for the determination of pinoresinoldiglucopyranoside in Qing' e Pill.展开更多
Aim A RP- HPLC method for determination of lycopene in microcapsules was established. Methods The HPLC assay was performed on an Alltima Cls (4.6 mm × 250 mm, 5μm) column with a mixture of methanol-THF-water ...Aim A RP- HPLC method for determination of lycopene in microcapsules was established. Methods The HPLC assay was performed on an Alltima Cls (4.6 mm × 250 mm, 5μm) column with a mixture of methanol-THF-water (66:30:4, V/V/V) as mobile phase at a flow rate of 1.5 mL·min^-1 and the UV detection wavelength was 472 nm. Results The linear range of lycopene was 3.6-18 μg·mL^-1, r = 0.999 8, the average recovery was from 99.81% to 101.06% with RSD less than 1.83%. The RSD of intra-day and interday precision were less than 3.34%. Conclusion The method is simple, accurate and suitable for the determination of lycopene in microcapsules.展开更多
Aim To establish a HPLC method for the separation of the enantiomers of zolmitriptan. Methods The separations were performed on Chiralcel OJ column with hexane-ethanol-diethylamine(85:15:0.2) as mobile phase at a ...Aim To establish a HPLC method for the separation of the enantiomers of zolmitriptan. Methods The separations were performed on Chiralcel OJ column with hexane-ethanol-diethylamine(85:15:0.2) as mobile phase at a flow rate of 0.8 mL·min^-1 and detecttion wavelength of 227 nm at 35 ℃. Several related parameters for separation were studied. Results Baseline separation (Rs 〉 1.5) was easily obtained in the case, and the R-isomer impurity in zolmitriptan was determined. Conclusion The method developed in this study has been successfully applied for quality-control purposes.展开更多
The leaf structure, content and the storage location of aloin in the leaves of six species of Aloe L. were studied by means of semi-thin section, high performance liquid chromatography (HPLC) and fluorescent microscop...The leaf structure, content and the storage location of aloin in the leaves of six species of Aloe L. were studied by means of semi-thin section, high performance liquid chromatography (HPLC) and fluorescent microscope. Results showed that all leaves consisted of epidermis, chlorenchyma, aquiferous tissue and vascular bundles. The leaves had the xeromorphic characteristics, including thickened epidermal cell wall, thickened cuticle, sunken stomata and well-developed aquiferous tissue. With the exception of thus, there were remarkable differences in leaf structure among the six species. The chlorenchyma cells were similar to palisade tissues in Aloe arborescens Mill. and A. mutabilis Pillans, but isodiametric in A. vera L., A. vera L. var. chinensis Berg., A. saponaria Hawer and A. greenii Bali. A. arborescens, A. mutabilis, A. very and A. vera var. chinensis included large parenchymatous cells at the vascular bundles, whereas no such cells were observed at the vascular bundles of A. saponaria and A. greenii. In A. arborescens, A. mutabilis and A. vera, the aquiferous tissue sheaths were present and composed of a layer of small parenchymatous cells without chloroplasts around the aquiferous tissue. While there were no aquiferous tissue sheaths in A. vera var. chinensis, A. saponaria and A. greenii. The HPLC revealed that the content of aloin was high in A. arborescens, low in A. vera, and very low in A. saponaria among the six species. The fluorescent microscopy showed that the yellow-green globule only appeared in the large parenchymatous cells of vascular bundles, vascular bundle sheath and aquiferous tissue sheath, but not in the chlorenchyma and aquiferous tissue. Consequently, the large parenchymatous cells of vascular bundles, vascular bundle sheath and aquiferous tissue sheath were the storage location of aloin. They were positively correlated with the content of aloin.展开更多
Microstructures of creep-aged 2524 (A1-4.3Cu-1.5Mg) aged at 170 ℃ with various stresses (0, 173 and 250 MPa) were studied on a creep machine. Ageing hardness curves under various stresses were plotted and the cor...Microstructures of creep-aged 2524 (A1-4.3Cu-1.5Mg) aged at 170 ℃ with various stresses (0, 173 and 250 MPa) were studied on a creep machine. Ageing hardness curves under various stresses were plotted and the corresponding microstructures were characterized by transmission electron microscopy (TEM). The results show that the value of peak hardness is increased, while the time to reach the peak hardness is reduced under an external stress. Meanwhile, the length of S(Al2CuMg) phase is shorter and the number density of S phases is larger in the creep-aged alloy. The predominant contribution to the peak hardness can be ascribed to the GPB zones with an elastic stress.展开更多
Aim An HPLC method for analyzing eleutheroside B (ELU B) and eleutheroside E(ELU E) , two of the main active substances of Acanthopanax preparations were studied. Methods Thesamples were analyzed on a kromasil ODS col...Aim An HPLC method for analyzing eleutheroside B (ELU B) and eleutheroside E(ELU E) , two of the main active substances of Acanthopanax preparations were studied. Methods Thesamples were analyzed on a kromasil ODS column with water-acetonitrile as a gradient mobile phase.The flow rate was 0.8 mL·min^(-1) and detecting wavelengths were 206 nm for ELU B, 220 nm for ELUE, solid phase extraction (SPE) and internal standard-salicin were selected. Results The recoveriesof Acanthopanax tablets and injection were 90.4% - 96.8% and 96.4% - 99.8% for ELU B, 87.7% -93.3%and 95.7% - 98.5% for ELU E, respectively. The linear ranges were 4.45 - 22.25 μg· mL^(-1) (r =0.999 8) and 5.11 - 25.55 μg·mL^(-1) ( r = 0.999 7) respectively. Conclusion This method can savethe time for cleaning the chromatographic system and improve sensitivity for Acanthopanaxpreparations , thus providing a way to evaluate the quality of Acanthopanax preparations.展开更多
Aim To study the pharmacokinetics of oxiracetam after single and multipleintravenous administrations in healthy volunteers. Method A HPLC method was used to determine theserum concentration of oxiracetam after intrave...Aim To study the pharmacokinetics of oxiracetam after single and multipleintravenous administrations in healthy volunteers. Method A HPLC method was used to determine theserum concentration of oxiracetam after intravenous single dose and daily dose of 2 000 mg for 7 din ten Chinese healthy volunteers. Pharmacokinetic analysis was carried out using Drug And Statisticsoftware. Results The AUC_(0-12), AUC_(0-∞), K_e, t_(1/2), MRT after a single dose of 2 000 mgoxiracetam were 256.26 ± 16.84 μg·mL^(-1)·h, 276.74 ±18.11 μg·mL^(-1)·h, 0.18 ±0.03 h^(-1),3.84±0.64 h, and 4.39 10.39 h, and after multiple doses of oxiracetam were 259.36 ±25.43μg·mL^(-1)·h, 285.59 ±27.38 μg·mL^(-1)·h, 0.17 ±0.04 h^(-1), 4.14 ± 0.82 h, and 4.87 ±0.69 h, respectively. Conclusion The pharmacokinetic parameters of oxiracetam do not differremarkably after single and multiple intravenous administration and there is accumulation in serumafter 2 000 mg multiple intravenous administration once a day fof 7 d.展开更多
Aim To optimize purification conditions of recombinant hirudin 3 in thefermentation broth and characterize the product. Methods Reambinant hirudin 3 was isolated andpurified from the fermentation broth by three column...Aim To optimize purification conditions of recombinant hirudin 3 in thefermentation broth and characterize the product. Methods Reambinant hirudin 3 was isolated andpurified from the fermentation broth by three column chromatography steps with macroporous resin,DEAE cellulose DES2 and preparative RP-HPLC, respectively, and the optimal conditions were obtained.Purity of the product was determined by SDS-PAGE and analytical RP-HPLC. The molecular weight wasdetermined by mass spec-trometry. The structure of the product was analyzed by peptide map.ResultsThe product with purity of 95.4786% was obtained after three purification steps in the optimumconditions with a total yield of 39%. The molecular weight of the product was 6 913.32 ± 6.55 Da,coincident to the theoretical molecular weight of r-hirudin 3. The structure of the product wascoincident to r-hirudin 3 either. Conclusion The optimized purification steps can be successfullyemployed for purification of r-hirudin 3 from E. coli using batch-type approaches. The productobtained with high purity was confirmed to be r-hirudin 3.展开更多
Ahn To establish an RP-HPLC method for determination of content of 1-phenylpropanol in its raw material and preparations. Methods Chromatography was carried out on a Dikma DiamonsilTM ODS column, using a mobile phase ...Ahn To establish an RP-HPLC method for determination of content of 1-phenylpropanol in its raw material and preparations. Methods Chromatography was carried out on a Dikma DiamonsilTM ODS column, using a mobile phase of methanol-water (55:45) with a flow rate at 1.0 mL·min^-1. The detection wavelength was 258 nm. Results Under the chromatographic condition, the peaks of 1-phenylpropanol and its related impurities separated completely; noninterference between the principal agent and adjuvants in preparations was performed. The calibration curve was linear over the range of 250 - 750μg·mL^-1 with the correlation coefficient of 0. 999 9. The average recovery was 100.2% ( RSD = 1.35% ). Conclusion This method is simple, rapid, accurate, specific, and can be used to detect the content and related compounds of phenylpropanol in its raw material and preparations.展开更多
Aim To establish an RP-HPLC method for simultaneous determination of 2"-O-rhamnosyl vitexin and vitexin in Chinese hawthorn leaf and its extract. Methods Chromatography was carfled out on Kromasil C18 column (250 mm...Aim To establish an RP-HPLC method for simultaneous determination of 2"-O-rhamnosyl vitexin and vitexin in Chinese hawthorn leaf and its extract. Methods Chromatography was carfled out on Kromasil C18 column (250 mm × 4.6 mm, 5 μm), using THF-CH3CN-H2O-H3PO4 (30 : 5: 125 : 0. 1) as the mobile phase at a flow rate of 1.0 mL·min^-1. The UV detection wavelength was 270 nm. Results The linear range of 2"-O-rhamnosyl vitexin and vitexin were 0. 106 4 μg - 2. 1280 μg ( r =0. 999 1 ) and 0. 139 2μg - 2. 784 0 μg ( r =0. 999 3 ), respectively. The average recoveries of 2"-O-rhamnosyl vitexin and vitexin in Chinese hawthorn leaf were 99.2% ( RSD = 2.80%, n = 6) and 100.6% ( RSD = 2.84%, n = 6), respectively. Conclusion This method is reproducible, simple, precise, and rapid for simultaneous determination of 2"-O-rhamnosyl vitexin and vitexin in Chinese hawthorn leaf and its extract, thereby providinge the basis for quality specification of Chinese hawthorn leaf and its extract.展开更多
文摘A transformation of naphthalene-based coalescenced mesophase pitch(NMP)to mesophase microbeads was achieved by heating a mixture of NMP and fullerene(C_(60)).This is different from the conventional process of the liquid-phase carbonization of isotropic pitch to the emergence of carbon microbeads in the matrix and finally their growth to form a 100%anisotropic bulk meso-phase,but rather a reverse transformation.The effects of C_(60) loading and reaction temperature on the morphological transformation of mesophase were investigated by polarizing optical and scanning electron microscopies.The physical changes in the NMP induced by C_(60) were characterized by thermogravimetric analysis,Fourier transform infrared spectroscopy,X-ray diffractometry and Raman spectroscopy.The results show that the coalesced NMP can be converted to a spherical type at 300-320℃ with the addition of 5%C_(60),and the size of the mesophase microbeads increases with increasing temperature.Furthermore,a model is established to ex-plain the unique induction effect of C_(60) in the transformation process.This work makes the morphological transformation of MP con-trollable,and provides a new idea for the understanding and research of mesophase pitch.
文摘Aim In the present study a RP-HPLC method was developed and validated toinvestigate the stability of baicalin aqueous solution. Methods The influences of temperature and pHon the stability of baicalin aqueous solution were investigated by classic homoiothermicacceleration test, and the pH for the most stable solution was determined. Results The time whenbaicalin suffered 10% loss was found to be 18.1 h, and the degradation activation energy of baicalinwas 79.1 kJ·moL^(-1) . The pH at which baicalin is most stable is 4.28. Conclusion The temperatureshould be kept at a lower level and the pH should be adjusted to near that for the most stablesolution in the production of baicalin preparations.
基金Supported by the Special Funds for Supervision on the Quality and Safety of Agricultural Products(GJFP201601503)~~
文摘[Objective] This study was conducted to develop a system for simultaneous determination of imidacloprid, diflubenzuron, thiabendazole and carbendazim in fruit juice by HPLC. [Method] Using acetonitrile as the extraction solvent, the pesticides in fruit juice were purified through a NH2 solid phase extraction (SPE) cartridge, then detected by HPLC. [Result] There was a good linear relationship between the peak area and the concentrations of imidacloprid, diflubenzuron, thiabendazole and carbendazim in a range of 0.05-5.0 μg/ml, and the linear correlation coefficient varied in a range of 0.999 0-0.999 8; the limit of detection for imidacloprid, diflubenzuron, thiabendazole and carbendazim was 0.003, 0.005, 0.003 and 0.007 mg/kg, respectively. The recovery rate of imidacloprid, diflubenzuron, thiabendazole and carbendazim standards added at three levels (0.1, 0.5 and 1.0 mg/kg) ranged from 82% to 107%, with RSD less than 4.5%. [Conclusion] The sensitivity, accuracy and precision of this method were able to meet the requirements for pesticide residue analysis.
基金Supported by the Key Project of Science and Technology of Anhui Province(08010302216)~~
文摘[Objective] The aim was to evaluate the uncertainty of determining aspartame in beverage by high performance liquid chromatography ( HPLC). [Method] The content of aspartame in beverage was determined by HPLC, then the source of uncertainty in the whole determination process was analyzed, and each component of uncertainty was evaluated and combined. [ Result] Through 6 repeated determinations by the method in GB/T 22254-2008 "Determination of Aspartame in Food", the average content of aspartame in beverage was (0.806 ±0.038) g/kg, and k =2. The main sources of uncertainty to affect the process were the sample weighting process, the preparation process of standard solution introduced by sample constant volume and the uncertainty introduced by fitting standard curve. ①The uncertainty of standard work-solution. The combined uncertainty of standard work-solution was 0.013 9, among them the uncertainty introduced by standard sample purity was 0.005 8, the standard uncertainty introduced by standard material weighting was 1.49 ×10^4, the relative uncertainty introduced by glass apparatus calibration in the preparation process of aspartame standard reserving solution was 0. 007 88, and the uncertainty introduced by glass apparatus calibration in the preparation process of standard work-solution was 0. 009 9. ②The uncertainty introduced by the preparation process of sample specimen. Among them the relative standard uncertainty introduced by sample weighting process was 0. 009, and the uncertainty introduced by sample constant volume was 0.000 78. ③The uncertainty introduced by the fitting process of standard curve. Among them the relative uncertainty of curve fitting was 0.002 46, the uncertainty introduced by the determined results of aspartame was 0.017 0, the total combined standard uncertainty was 0.023 9, and the expanded standard uncertainty was 0.019. [ Conclusion] The uncertainty components of standard solution, standard curve and repeatability are the main sources of uncertainty, while those of sample weighting and sample constant volume account for little proportion.
基金Supported by Major Special Science and Technology Project of Guangdong Province(2010B080703035)~~
文摘ObjectiveThis study aimed to investigate the biodegradation effect and biodegradation mechanism of aniline aerofloat wastewater. MethodSmall-scale processing of simulated aniline aerofloat wastewater was carried out with SBR (Sequencing Batch Reactor) system; intermediate products in the process were analyzed using high-performance liquid chromatography. ResultAccording to the experimental results, the small-scale process was basically stably operated after 40 days of activation and regulation, leading to relatively ideal degradation effect on aniline aerofloat, the COD removal efficiency reached 64.3% , degradation rate of aniline aerofloat reached 93.4%, which could be applied in the treatment of mine flotation wastewater containing such pollutant. During the degradation process, pH increased from 5.83 to 6.60 and then dropped to 6.17, which might be caused by the thiocyanate ions and aniline generated in the degradation process. Aniline aerofloat mainly produced two preliminary products during the biodegradation process: aniline and a substance that was difficult to be biodegraded under aerobic conditions, which was the main reason for the relatively high COD value in effluent. Furthermore, aniline was eventually biodegraded. ConclusionThis study provided basis for the development of biological treatment of flotation wastewater in China and showed great significance for the improvement of ecological environment around the mines.
文摘Aim To develop and determine pinoresinol diglucopyranoside in Qing'e Pill, atraditional Chinese compound preparation containing Eucommia ulmoides Oliv. as the principal drug,by a reverse-phase high-performance liquid chromatographic method (RP-HPLC) . Methods The extract ofQing'e Pill was refluxed with 75% ethanol, purified on an AB-8 macroporous adsorption resin columnand then injected into HPLC system. The HPLC assay was performed on an ODS analytical column with amixture of methanol-acetonitrile-water (24:3:78, V/V/V) as the mobile phase at a flow-rate of 1.0mL·min^(-1), and a UV detector set at 227 nm. Results Good linearity between peak area andconcentration was found in the range of 5.5 - 170 μg·mL^(-1) for pinoresinol diglucopyranoside ( r> 0.9998) . The average recovery was 99.3%. The intra-day assay RSD and the inter-day assay RSDwere 1.3% and 2.8%, respectively (n = 5). The content of pinoresinol diglucopyranoside in Qing'ePill was determined to be 0.446 +- 0.012 mg·g^(-1) (n = 10). Conclusion The RP-HPLC method wasproved to be sensitive, specific, accurate and precise for the determination of pinoresinoldiglucopyranoside in Qing' e Pill.
基金Special Research Foundation of Ph.D. Study in University(20040291004)Major Project of Chinese(National Programs for Fundamental Research(2003CB716000)
文摘Aim A RP- HPLC method for determination of lycopene in microcapsules was established. Methods The HPLC assay was performed on an Alltima Cls (4.6 mm × 250 mm, 5μm) column with a mixture of methanol-THF-water (66:30:4, V/V/V) as mobile phase at a flow rate of 1.5 mL·min^-1 and the UV detection wavelength was 472 nm. Results The linear range of lycopene was 3.6-18 μg·mL^-1, r = 0.999 8, the average recovery was from 99.81% to 101.06% with RSD less than 1.83%. The RSD of intra-day and interday precision were less than 3.34%. Conclusion The method is simple, accurate and suitable for the determination of lycopene in microcapsules.
文摘Aim To establish a HPLC method for the separation of the enantiomers of zolmitriptan. Methods The separations were performed on Chiralcel OJ column with hexane-ethanol-diethylamine(85:15:0.2) as mobile phase at a flow rate of 0.8 mL·min^-1 and detecttion wavelength of 227 nm at 35 ℃. Several related parameters for separation were studied. Results Baseline separation (Rs 〉 1.5) was easily obtained in the case, and the R-isomer impurity in zolmitriptan was determined. Conclusion The method developed in this study has been successfully applied for quality-control purposes.
文摘The leaf structure, content and the storage location of aloin in the leaves of six species of Aloe L. were studied by means of semi-thin section, high performance liquid chromatography (HPLC) and fluorescent microscope. Results showed that all leaves consisted of epidermis, chlorenchyma, aquiferous tissue and vascular bundles. The leaves had the xeromorphic characteristics, including thickened epidermal cell wall, thickened cuticle, sunken stomata and well-developed aquiferous tissue. With the exception of thus, there were remarkable differences in leaf structure among the six species. The chlorenchyma cells were similar to palisade tissues in Aloe arborescens Mill. and A. mutabilis Pillans, but isodiametric in A. vera L., A. vera L. var. chinensis Berg., A. saponaria Hawer and A. greenii Bali. A. arborescens, A. mutabilis, A. very and A. vera var. chinensis included large parenchymatous cells at the vascular bundles, whereas no such cells were observed at the vascular bundles of A. saponaria and A. greenii. In A. arborescens, A. mutabilis and A. vera, the aquiferous tissue sheaths were present and composed of a layer of small parenchymatous cells without chloroplasts around the aquiferous tissue. While there were no aquiferous tissue sheaths in A. vera var. chinensis, A. saponaria and A. greenii. The HPLC revealed that the content of aloin was high in A. arborescens, low in A. vera, and very low in A. saponaria among the six species. The fluorescent microscopy showed that the yellow-green globule only appeared in the large parenchymatous cells of vascular bundles, vascular bundle sheath and aquiferous tissue sheath, but not in the chlorenchyma and aquiferous tissue. Consequently, the large parenchymatous cells of vascular bundles, vascular bundle sheath and aquiferous tissue sheath were the storage location of aloin. They were positively correlated with the content of aloin.
基金Project (2009BAG12A07-B02) supported by the National Science & Technology Pillar Program during the 11th Five-Year Plan Period,ChinaProject supported by Innovative Research Team in University of Liaoning Province,ChinaProject (51001022) supported by the National Natural Science Foundation of China
文摘Microstructures of creep-aged 2524 (A1-4.3Cu-1.5Mg) aged at 170 ℃ with various stresses (0, 173 and 250 MPa) were studied on a creep machine. Ageing hardness curves under various stresses were plotted and the corresponding microstructures were characterized by transmission electron microscopy (TEM). The results show that the value of peak hardness is increased, while the time to reach the peak hardness is reduced under an external stress. Meanwhile, the length of S(Al2CuMg) phase is shorter and the number density of S phases is larger in the creep-aged alloy. The predominant contribution to the peak hardness can be ascribed to the GPB zones with an elastic stress.
文摘Aim An HPLC method for analyzing eleutheroside B (ELU B) and eleutheroside E(ELU E) , two of the main active substances of Acanthopanax preparations were studied. Methods Thesamples were analyzed on a kromasil ODS column with water-acetonitrile as a gradient mobile phase.The flow rate was 0.8 mL·min^(-1) and detecting wavelengths were 206 nm for ELU B, 220 nm for ELUE, solid phase extraction (SPE) and internal standard-salicin were selected. Results The recoveriesof Acanthopanax tablets and injection were 90.4% - 96.8% and 96.4% - 99.8% for ELU B, 87.7% -93.3%and 95.7% - 98.5% for ELU E, respectively. The linear ranges were 4.45 - 22.25 μg· mL^(-1) (r =0.999 8) and 5.11 - 25.55 μg·mL^(-1) ( r = 0.999 7) respectively. Conclusion This method can savethe time for cleaning the chromatographic system and improve sensitivity for Acanthopanaxpreparations , thus providing a way to evaluate the quality of Acanthopanax preparations.
文摘Aim To study the pharmacokinetics of oxiracetam after single and multipleintravenous administrations in healthy volunteers. Method A HPLC method was used to determine theserum concentration of oxiracetam after intravenous single dose and daily dose of 2 000 mg for 7 din ten Chinese healthy volunteers. Pharmacokinetic analysis was carried out using Drug And Statisticsoftware. Results The AUC_(0-12), AUC_(0-∞), K_e, t_(1/2), MRT after a single dose of 2 000 mgoxiracetam were 256.26 ± 16.84 μg·mL^(-1)·h, 276.74 ±18.11 μg·mL^(-1)·h, 0.18 ±0.03 h^(-1),3.84±0.64 h, and 4.39 10.39 h, and after multiple doses of oxiracetam were 259.36 ±25.43μg·mL^(-1)·h, 285.59 ±27.38 μg·mL^(-1)·h, 0.17 ±0.04 h^(-1), 4.14 ± 0.82 h, and 4.87 ±0.69 h, respectively. Conclusion The pharmacokinetic parameters of oxiracetam do not differremarkably after single and multiple intravenous administration and there is accumulation in serumafter 2 000 mg multiple intravenous administration once a day fof 7 d.
文摘Aim To optimize purification conditions of recombinant hirudin 3 in thefermentation broth and characterize the product. Methods Reambinant hirudin 3 was isolated andpurified from the fermentation broth by three column chromatography steps with macroporous resin,DEAE cellulose DES2 and preparative RP-HPLC, respectively, and the optimal conditions were obtained.Purity of the product was determined by SDS-PAGE and analytical RP-HPLC. The molecular weight wasdetermined by mass spec-trometry. The structure of the product was analyzed by peptide map.ResultsThe product with purity of 95.4786% was obtained after three purification steps in the optimumconditions with a total yield of 39%. The molecular weight of the product was 6 913.32 ± 6.55 Da,coincident to the theoretical molecular weight of r-hirudin 3. The structure of the product wascoincident to r-hirudin 3 either. Conclusion The optimized purification steps can be successfullyemployed for purification of r-hirudin 3 from E. coli using batch-type approaches. The productobtained with high purity was confirmed to be r-hirudin 3.
文摘Ahn To establish an RP-HPLC method for determination of content of 1-phenylpropanol in its raw material and preparations. Methods Chromatography was carried out on a Dikma DiamonsilTM ODS column, using a mobile phase of methanol-water (55:45) with a flow rate at 1.0 mL·min^-1. The detection wavelength was 258 nm. Results Under the chromatographic condition, the peaks of 1-phenylpropanol and its related impurities separated completely; noninterference between the principal agent and adjuvants in preparations was performed. The calibration curve was linear over the range of 250 - 750μg·mL^-1 with the correlation coefficient of 0. 999 9. The average recovery was 100.2% ( RSD = 1.35% ). Conclusion This method is simple, rapid, accurate, specific, and can be used to detect the content and related compounds of phenylpropanol in its raw material and preparations.
文摘Aim To establish an RP-HPLC method for simultaneous determination of 2"-O-rhamnosyl vitexin and vitexin in Chinese hawthorn leaf and its extract. Methods Chromatography was carfled out on Kromasil C18 column (250 mm × 4.6 mm, 5 μm), using THF-CH3CN-H2O-H3PO4 (30 : 5: 125 : 0. 1) as the mobile phase at a flow rate of 1.0 mL·min^-1. The UV detection wavelength was 270 nm. Results The linear range of 2"-O-rhamnosyl vitexin and vitexin were 0. 106 4 μg - 2. 1280 μg ( r =0. 999 1 ) and 0. 139 2μg - 2. 784 0 μg ( r =0. 999 3 ), respectively. The average recoveries of 2"-O-rhamnosyl vitexin and vitexin in Chinese hawthorn leaf were 99.2% ( RSD = 2.80%, n = 6) and 100.6% ( RSD = 2.84%, n = 6), respectively. Conclusion This method is reproducible, simple, precise, and rapid for simultaneous determination of 2"-O-rhamnosyl vitexin and vitexin in Chinese hawthorn leaf and its extract, thereby providinge the basis for quality specification of Chinese hawthorn leaf and its extract.