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@#The aim of this study was to establish a high performance liquid chromatography-mass spectrometry method for the determination of 5-(4′-(bromomethyl)-［1, 1′-biphenyl］-2-yl)- 1H-tetrazole(BBT1)and 5-(4′-(dibromomethyl)-［1, 1′-biphenyl］-2-yl)-1H-tetrazole(BBT2), which are two genotoxic impurities in olmesartan medoxomil. Chromatographic separation was based on an Agilent Zorbax Eclipse Plus C18(250 mm × 4. 6 mm, 5 μm)column using water(containing 0. 1% formic acid)- acetonitrile as mobile phase in gradient elution mode. Mass spectrometry was operated in positive ion mode. Selective ion monitors were set at m/z 315 for BBT1 and at m/z 395 for BBT2. Good linear correlations were observed in the range of 0. 009 4- 0. 561 0 μg/mL(r=0. 998)with the quantification limit at 9. 35 ng/mL and the detection limit at 3. 12 ng/mL for BBT1, and in the range of 0. 018 2- 0. 547 5 μg/mL(r=0. 999)with the quantification limit at 18. 25 ng/mL and the detection limit at 6. 08 ng/mL for BBT2. Furthermore, the average recoveries of the three spiked concentration level were 96. 5%(n=9, RSD=4. 8%)and 98. 0%(n=9, RSD=5. 1%)for BBT1 and BBT2, respectively. The proposed method is simple, specific and accurate, and quite suitable for the determination of BBT1 and BBT2 in olmesartan medoxomil.
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Objective:To establish the purification process of citral in volatile oil from Fructus Litseae by molecular distillation . Methods:The twice molecular distillation , GC and area normalization method were used for extracting citral , detecting the contents and describing the efficacy of purification , respectively .The mainly factor concerned was temperature .The conditions were as follows:the system pressure was 3000 Pa, the scraper speed was 300 r· min-1 , the feeding rate was 7.5 ml· min-1 and the distillation tem-perature was 45℃for the first time molecular distillation; the system pressure was 5 Pa, the scraper speed was 300 r· min-1 , the feeding rate was 7.5 ml· min-1 and the distillation temperature was 45℃ for the second time molecular distillation .GC was utilized under the following conditions:the sample injection was 1 μl, the column temperature was programmed from 70℃to 250℃, the split ratio was 1:100 and the flow rate of carrier gas was 1.0 ml· min-1 .Results: The content and yield of citral was up to 95.0％ and 87.5％, respectively.Conclusion:The method of twice molecular distillation in combination with GC to purify and detect citral is es -tablished in the work, which can provide reference for the research on the chemical components of Litsea cubeba(Lour.) Pers.and the preparation of citral .
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DNA barcoding and HPLC specific chromatogram were used to identify three kinds of Plumeria flowers respectively. DNAs extracted from the three Plumeria species were amplified by PCR with universal primers, and the psbA-trnH region was selected. All the amplified products were sequenced and the results were analyzed by MEGA 5.0. Chemometric methods including principal components analysis and hierarchical clustering analysis were conducted on the SAS 9.0 software to demonstrate the variability among samples. In conclusion, the psbA-trnH of all samples were successfully amplified from total DNA and sequenced. These three varieties of Plumeria can be differentiated by the psbA-trnH region and clustered into three groups respectively through building neighbor joining tree, which conformed to their germplasm origins. However, it was hard to distinguish them by HPLC specific chromatograms combined with chemometrics analysis. These indicated that DNA barcoding was a promising and reliable tool for the identification of three kinds of Plumeria flowers compared to HPLC specific chromatogram generally used. It could be treated as a powerful complementary method for traditional authentication, especially for those varieties which are difficult to be identified by conventional chromatography.
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Objective: To optimize the extraction process of volatile oil from Fructus Litseae.Methods: Supercritical CO2 extraction (SFE-CO2) was used to extract volatile oil from Fructus Litseae, and the extraction process was optimized by a central composite design-response surface method (CCD-RSM).The kind and content of volatile oil extracted by SFE-CO2 and steam distillation (SD) were detected by gas chromatography-mass spectrometer (GC-MS).Results: The highest extraction rate of the total effective constituents was 66.26% when the optimum conditions were as follows: the extraction temperature was 44 ℃, the extraction pressure was 26 MPa, entrainer ethanol was 11 ml and the extraction time was 40 min.It was revealed that neral, geranial and limonene were the major constituents.Compared with that of SD, the kind of volatile oil extracted by SFE-CO2 was fewer while the content of citral extracted by SFE-CO2 was higher.Conclusion: The extraction process optimized by CCD-RSM provides reference for the extraction method and quality control of volatile oil from Fructus Litseae.
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Objective:To characterize the volatile compounds in 10 batches of disposable infusion sets and 6 batches of nasal can-nulas by GC-MS and determine the main odor-active compounds. Methods:The volatile components were extracted using a headspace sampler. An HP-5MS capillary column (30 m × 0. 25 mm,0. 25 μm) was adopted, and the qualitative analysis was performed by total ion chromatography ( TIC) of full scan with temperature programmer. Results:A total of 19 major volatile compounds were identified, which were hydrocarbon, alcohol and carbonyl compounds (such as aldehyde and ester). Based on the combination of odor test and GC-MS, the concentration of alcohol compounds (2-ethyl hexanol, 2-EH) had the most notable effect on the odor of samples. Conclu-sion:The samples with unacceptable order contain 2-EH with relatively high content, which should be paid more attention.
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A high-speed counter-current chromatography (HSCCC) method was successfully developed for the preparative separation and purification of deoxyschizandrin from Schisandrae Sphenantherae Fructus in one step. The purity of deoxyschizandrin was 98.5%, and the structure was identified by MS, UV and NMR. This method was simple, fast, convenient and appropriate to prepare pure compound as reference substances for related research on Schisandrae Sphenantherae Fructus.
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Heteroclitin D (H.D) was successfully isolated from Kadsurae Caulis by using flash chromatography and recrystallized by methanol, 10.2 mg of H.D was obtained from 4.86 g of crude extract, and the purity determined by HPLC was 99.4%. The structure was identified by UV, IR, MS, and NMR analysis. The fast, simple and efficient method can be applied to the preparation of reference substance of H. D.
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An efficient method for the isolation and purification of 12,13-dihydroxyeuparin from Radix Eupatorii Chinensis by high speed counter-current chromatography (HSCCC) was established in this paper.The ether extracts of Radix Eupatorii Chinensis were purified by HSCCC with a solvent system of hexyl hydride ethyl acetate-methanol-water (1∶2∶1∶2,v/v/v/v).The upper phase was used as the stationary phase and the lower phase as the mobile phase.About 8.4 mg of 12,13-dihydroxyeuparin was obtained from 200 mg of ether extracts from Radix Eupatorii Chinensis in one-step HSCCC separation,with the purity of 96.71％,as determined by HPLC.After methanolwater recrystallization,the purity of 12,13-dihydroxyeuparin reached 99.83％.Such a simple and effective method was fairly useful to prepare pure compound as reference substances for related study on Radix Eupatorii Chinensis.
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A reversed phase high performance liquid chromatography （HPLC） method was established for the simultaneous determination of 12, 13-dihydroxyeuparin and glycyrrhizic acid in Yanyanfang mixture. A Grace Apollo Cl8 column （250 mm × 4.6 mm, 5 μm） was used as the stationary phase and the mobile phase was composed of acetonitrile and aqueous phosphoric acid （0.2%, v/v）. Gradient elution was carried out at the flow rate of 1.0 mL/min and the column temperature was 30 ℃. An ultraviolet （UV） detector was used with a selected wavelength of 240 nm. Calibration curves were linear within the concentration range of 4.6-45.75 μg/mL for 12, 13-dihydroxyeuparin （r〉0.9999） and 106.9-1068.9μg/mL for glycyrrhizic acid （r〉0.9999）, respectively. Recoveries were 102.18% for 12, 13-dihydroxyeuparin and 101.17% for glycyrrhizic acid. The method developed could be applied to the simultaneous determination of 12, 13- dihydroxyeuparin and glycyrrhizic acid in Yanyanfang mixture.
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A reversed phase high performance liquid chromatography (HPLC) method was established for the simultaneous determination of 12,13-dihydroxyeuparin and glycyrrhizic acid in Yanyanfang mixture.A Grace Apollo C18 column (250 mm× 4.6 mm,5 μm) was used as the stationary phase and the mobile phase was composed of acetonitrile and aqueous phosphoric acid (0.2％,v/v).Gradient elution was carried out at the flow rate of 1.0 mL/min and the column temperature was 30 ℃.An ultraviolet (UV) detector was used with a selected wavelength of 240 nm.Calibration curves were linear within the concentration range of 4.6-45.75 μg/mL for 12,13-dihydroxyeuparin (r＞0.9999) and 106.9-1068.9μg/mL for glycyrrhizic acid (r＞0.9999),respectively.Recoveries were 102.18 ％ for 12,13-dihydroxyeuparin and 101.17％ for glycyrrhizic acid.The method developed could be applied to the simultaneous determination of 12,13-dihydroxyeuparin and glycyrrhizic acid in Yanyanfang mixture.
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Objective To set up the reference standard of cyclovirobuxine D.Methods Thermal analysis,HPLC/MS,HPLC with terminal wavelength,HPLC with fluorescence derivation and with ultraviolet derivation,TLC and nonaqueous titration methods were applied to determine the content of cyclovirobuxine D control.Results Thermal analysis can not be used to analyse the purity of cyclovirobuxine D ,and HPLC/MS,HPLC with terminal wavelength,HPLC with fluorescence derivation and HPLC with ultraviolet derivation can obtain the same purity.Conclusion The methods used for the assay of cyclovirobuxine D control were practical.