[Show abstract][Hide abstract] ABSTRACT: In this study, an accelerated solvent extraction dispersive liquid-liquid microextraction coupled with gas chromatography and mass spectrometry was established and employed for the extraction, concentration and analysis of essential oil constituents from Ligusticum chuanxiong Hort. Response surface methodology was performed to optimize the key parameters in accelerated solvent extraction on the extraction efficiency, and key parameters in dispersive liquid-liquid microextraction were discussed as well. Two representative constituents in Ligusticum chuanxiong Hort, (Z)-ligustilide and n-butylphthalide, were quantitatively analyzed. It was shown that the qualitative result of the accelerated solvent extraction dispersive liquid-liquid microextraction approach was in good agreement with that of hydro-distillation, whereas the proposed approach took far less extraction time (30 min), consumed less plant material (usually <1 g, 0.01 g for this study) and solvent (less than 20 mL) than the conventional system. To sum up, the proposed method could be recommended as a new approach in the extraction and analysis of essential oil. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
No preview · Article · Aug 2015 · Journal of Separation Science
[Show abstract][Hide abstract] ABSTRACT: Sodium Tanshinone IIA Sulfonate, the chemical modification product of Tanshinon IIA (STIIAS) is widely used in clinical treatment of angiocardiopathy, and the preparation of reference compounds of related substances for quality control is necessary. A method for separating three related substances from the bulk drug of STIIAS with high-speed counter-current chromatography (HSCCC) was developed. A solvent system composed of chloroform-n-butanol-methanol-water (17:0.3:14:9) was used and 0.5% saturated ammonium acetate aqueous solution was added to depress the emulsification in order to enhance sample loading capacity. Twelve related substances were identified in the bulk drug by HPLC-DAD and liquid chromatography/multistage tandem mass spectrometry (LC-MS(n)). Among them, three compounds were prepared and confirmed with (1)H NMR, one was identified without pretreatment, and seven components were identified after HSCCC enrichment since the contents of them were too low to be detected through direct LC-MS(n) injection. This research successfully broadened the application of HSCCC and introduced it to the field of impurities preparation of chemical medicine.
No preview · Article · Mar 2013 · Journal of Chromatography A
[Show abstract][Hide abstract] ABSTRACT: Experiments play a crucial role in the cultivation of the innovative ability. The students' ability of comprehensive innovation and application could be enhanced by setting formulation of the medicine quality's standards in the experimental course of pharmaceutical analysis. Furthermore, the students' professional thoughts and comprehensive quality could also be cultivated in all-around way. This paper will introduce the implementation methods and the corresponding effects of the designing experiment.
No preview · Article · Dec 2011 · Pharmaceutical Care and Research
[Show abstract][Hide abstract] ABSTRACT: A high-performance liquid chromatography-diode array detection/electrospray ionization mass spectrometry (HPLC-DAD/ESI-MS) method was applied to the characterization of ten iridoid glycosides in Gardenia jasminoides Ellis, a traditional Chinese medicine. During the process of structural elucidation, two groups of isomers including two epimers were structurally characterized and differentiated according to their distinctive fragmentation patterns which were closely related to their isomeric differentiations. Subsequently, the major compounds were purified by multi-dimensional chromatography and semi-preparative HPLC and the structure identification was confirmed with NMR techniques. The major fragmentation pathways of iridoid glycosides in Gardenia jasminoides Ellis obtained through the MS data were schemed systematically, which provided the best sensitivity and specificity for characterization of the iridoid glycosides especially the isomers so far. Based on the fragmentation patterns of iridoid glycosides concluded, seven major iridoid glycosides were characterized in rat plasma after intravenous administration of Gardenia jasminoides Ellis.
No preview · Article · Sep 2010 · Rapid Communications in Mass Spectrometry
[Show abstract][Hide abstract] ABSTRACT: Further studies of active coumarin components in Radix Angelicae Dahuricae (AE) are absolutely essential to provide data on pharmacology, toxicology and quality for innovative drug candidates. Thus, the preparation of active component standards and the administration of coumarin monomers should be carried out. The isolation of the low-level active components from complex Traditional Chinese Medicine (TCM) samples necessitates the development of rapid, simple and economical modern extraction, separation, identification and purification methods.
To develop an efficient strategy for the rapid extraction, separation, identification and purification of coumarins from AE.
First, active coumarins in AE were extracted with microwave-assisted extraction (MAE) after the extraction conditions were optimised. Second, gradient extraction methods with MAE were used to partially purify AE. Third, a high-performance liquid chromatography-diode array detection-electrospray ionisation tandem mass spectrometry (HPLC-DAD-ESI-MS/MS) method was applied for the preliminary on-line identification and screening of the main coumarins in AE extract. Finally, a two-dimensional preparative high-performance liquid chromatography-diode array detection (2D-prep-HPLC-DAD) system was developed for further preparative separation of those target components.
Altogether 10 coumarins have been identified and five of them including xanthotoxol, osthenol, oxypeucedanin hydrate, byakangelicin and imperatorin were deemed as target components for the preparative isolation. All of the five isolated coumarins were at high purities of over 99% and the production rate was much higher than the traditional methods.
The present paper demonstrates that these consecutive approaches are very useful for to isolate chemical constituents from TCM.
No preview · Article · Sep 2010 · Phytochemical Analysis
[Show abstract][Hide abstract] ABSTRACT: An ion-pair reverse-phase high performance liquid chromatographic method with UV-vis detection has been developed for the determination of total free iodine in rabbit plasma after vaginal administration of povidone-iodine (PVP-I). Sample preparation was done by protein precipitation with acetonitrile in 96-well format and aspirin was used as the internal standard. The 100 microL sodium thiosulfate solution (5 g L(-1)) was added to 100 microL plasma sample before protein precipitation, to convert the total free iodine in plasma to iodide (I(-)). Separation was performed on a C(18) column (200 x 4.6 mm i.d., 5 microm). The mobile phase consisting of a mixture of water phase (containing 10 mmol L(-1) 18-crown-6 ether, 5 mmol L(-1) octylamine and 5 mmol L(-1) sodium dihydrogen phosphate, pH adjusted to 6.0 with phosphoric acid) and acetonitrile in the ratio 70:30 (v/v) was delivered isocraticly at a flow rate of 1.0 mL min(-1). The method was sensitive with a lower limit of quantification of 0.005 microg mL(-1), with good linearity (r(2) > 0.9990) over the linear range of 0.005-2 microg mL(-1). All the validation data, such as linearity, accuracy and precision, were within the required limits. The method was successfully applied to study the pharmacokinetic of PVP-I in rabbits after vaginal administration.
No preview · Article · Nov 2009 · Biomedical Chromatography
[Show abstract][Hide abstract] ABSTRACT: A two-dimensional column-switching system without sample loop trapping, where two columns were operated via a six-port switching valve, was employed in the isolation and purification of five isoflavonoids from Rhizoma Belamcandae: tectoridin, iridin, tectorigenin, irigenin and irisflorentin. The introduction of the six-port switching value, instead of a sample loop, assured 100% recovery from the first dimension to the second, and the injection volumes of the second dimension were not restricted. Two configurations were tested in this study. In the first mode, only one column was used in the second dimension and two 'heart-cutting' fractions were transported to the same second-dimensional column. In the second mode, two parallel columns were used in the second dimension and two fractions were transported to the two columns. Between the two configurations, the one with two second dimensional columns had double sample size, better resolution and one more purified compound. Both two-dimensional configurations consumed less solvent with even greater efficiency and shorter cycle time compared with conventional gradient methods. All of the isoflavonoids were isolated at high purities of greater than 95% with yields of above 82%.
No preview · Article · Oct 2009 · Biomedical Chromatography
[Show abstract][Hide abstract] ABSTRACT: A rapid HPLC method using a monolithic column with fluorescence detection has been developed for determination of telmisartan in human plasma. Sample preparation was done by protein precipitation with acetonitrile and naproxen was used as IS. The compounds were detected by fluorescence detection, using an excitation wavelength of 300 nm and emission wavelength of 385 nm. Calibration curves of telmisartan were linear in the range of 1-200 ng/mL. The assay was high throughput, sensitive and precise, and it was successfully applied to a bioequivalence study of two formulations of telmisartan.
No preview · Article · Sep 2009 · Journal of chromatography. B, Analytical technologies in the biomedical and life sciences
[Show abstract][Hide abstract] ABSTRACT: Three flavonoids including 4″′-O-rhamnosylrutin, 2″-O-rhamnosylvitexin, and 4″-O-glucosylvitexin were isolated and purified from the hawthorn leaves by high speed countercurrent chromatography (HSCCC), combined together with isocratic preparative reversed-phase high performance liquid chromatography. Analytical HSCCC was used for the preliminary selection of a suitable solvent system composed of n-butanol-water (1:1, v/v). After two useful fractions were obtained by HSCCC using the optimal solvent system, one of them, fraction II, was further purified by reversed-phase semipreparative high performance liquid chromatography. From 500 mg partially purified extract of the hawthorn leaves, 188.4 mg 2″-O-rhamnosylvitexin, 28.5 mg 4″′-O-rhamnosylrutin, and 55.3 mg 4″-O-glucosylvitexin with purities of over 97%, respectively, were obtained. The structure identification of all pure fractions was carried out by UV, MS, H NMR and C NMR.
No preview · Article · Aug 2009 · Journal of Liquid Chromatography & Related Technologies
[Show abstract][Hide abstract] ABSTRACT: The pressurized capillary electrochromatography (pCEC) was utilized for the separation and determination of coumarins in Fructus cnidii extracts from 12 different regions. After a thorough study of analytical parameters such as acetonitrile content of the mobile phase, the concentration and pH of the buffer, and the applied voltage, a methodology was proposed to separate and determine six coumarins of F. cnidii extracts in less than 15 min. The experiments were performed in an in-house packed column with a monolithic outlet frit under the optimal conditions: pH 4.0 ammonium acetate buffer at 10 mM containing 50% acetonitrile at -6kV applied voltage. The calibration curves were linear in the range of 10.0-100.0 microg/mL for bergapten, 20.0-200.0 microg/mL for imperatorin, 5.0-400.0 microg/mL for osthole, 10.0-100.0 microg/mL for 2'-acetylangelicin, 10.0-200.0 microg/mL for oroselone, and 10.0-200.0 microg/mL for O-acetylcolumbianetin. The correlation coefficients were between 0.9967 and 0.9995. With this pCEC system, fingerprints of F. cnidii extracts were preliminarily established to distinguish three types of coumarins by characteristic peaks, and the quality of various sources of raw materials was evaluated by determining the contents of six coumarins.
No preview · Article · Jun 2009 · Journal of pharmaceutical and biomedical analysis
[Show abstract][Hide abstract] ABSTRACT: A two-dimensional column-switching system without sample loop trapping, where two columns were switched directly via a six-port two-position switching valve, was successfully applied for the first time to the isolation and purification of six iridoid glycosides including geniposide, gardenoside, shanzhiside, scandoside methyl ester, deacetyl-asperulosidic acid methyl ester and genipin-1-beta-D-gentiobioside from Gardenia jasminoides Ellis, a plant used in the traditional Chinese medicine. The introduction of the six-port switching valve instead of sample loop assured 100% recovery from the first dimension to the second, and the injection volumes of the second dimension could reach 20 ml. In this mode of operation, the sample size of the two-dimensional approach was more than 1.3 times that of conventional gradient methods with even less solvent consumption. And the simultaneous operations of the two dimensions allowed the cycle time to be less than 19 min, compared with that (90 min) in the gradient elution single-dimension mode of operation. All of the six isolated iridoid glycosides were isolated at high purities of over 99% with approximately 96% recoveries.
No preview · Article · Nov 2007 · Journal of Chromatography B
[Show abstract][Hide abstract] ABSTRACT: An analytical method incorporating high-performance liquid chromatography (HPLC) with MS and UV-detection was developed for the qualitative and quantitative determination of alkaloids in Corydalis yanhusuo. Ten alkaloids, including seven tertiary alkaloids and three quaternary alkaloids, were identified by comparing their retention times, UV and MS spectra with those of authentic compounds. Furthermore, the collision-induced dissociations of the [M+H](+) and [M](+) ions were studied to clarify the MS behavior of the different types of alkaloids. In positive ion electrospray ionization tandem mass spectrometry (ESI-MS) all the tertiary alkaloids yielded prominent [M+H](+) ions and quaternary alkaloids yielded prominent [M](+) ions in the first order mass spectra. Fragments involving losses of H, CH(3), CO, H(2)O and OCH(3) were observed in the MS/MS spectra. In addition, quantification of the 10 alkaloids in Corydalis yanhusuo from methanol and ethyl acetate extract of different origins were performed by this method, which provides a new tool for the assessment of quality of Corydalis yanhusuo preparations. The method provides the best sensitivity and specificity for characterization and quantitative determination of the alkaloids in Corydalis yanhusuo so far.
No preview · Article · Nov 2007 · Journal of Pharmaceutical and Biomedical Analysis
[Show abstract][Hide abstract] ABSTRACT: The dried flower buds of Magnolia biondii Pamp are one of the most widely used medicinal plants officially listed in the Chinese Pharmacopoeia. A 2-D column-switching system without sample loop trapping, where two columns were switched directly via a six-port two-position switching valve, was successfully applied for the first time to the isolation and purification of five lignans including pinoresinol dimethyl ether, magnolin, epi-magnolin A, fargesin, and demethoxyaschantin from M. biondii Pamp after microwave-assisted extraction. The introduction of the six-port switching valve instead of sample loop assured 100% recovery from the first dimension to the second, and the injection volumes of the second dimension could reach 12 mL. In this mode of operation, the solvent consumption of the 2-D approach was less than 30% that of conventional gradient methods with even larger sample size. The simultaneous operations of the two dimensions allowed the cycle time to be less than 16 min, compared to 90 min in the gradient elution single-dimension mode of operation. All of the five lignans were isolated at high purities of over 99% with approximately 95% recoveries.
No preview · Article · Oct 2007 · Journal of Separation Science
[Show abstract][Hide abstract] ABSTRACT: An efficient on-line purity monitoring strategy based on on-line coupling of high-speed counter-current chromatography (HSCCC) with high-performance liquid chromatography-diode array detection (HPLC-DAD) was successfully applied for the first time to the isolation and purification of 5-hydroxymethyl-furancarboxaldehyde (5-HMF), mangiferin and neomangiferin from the Chinese medicinal plant Anemarrhena asphodeloides Bunge, a plant used in the traditional Chinese medicine. The introduction of on-line purity monitoring in HSCCC has greatly improved the efficiency of this technique by overcoming the drawbacks of post-purification sample handling in HSCCC isolation. The effluent from the outlet of HSCCC was split into two parts, and one was collected, while the other was introduced directly through a switch valve into a HPLC-DAD system for purity monitoring. Using this method the desired fractions with high purities could be collected. From 600 mg partially purified extract, 165.6 mg neomangiferin and 292.8 mg mangiferin with purities of 98.9 and 99.5%, respectively, were obtained with a two-phase solvent system composed of n-butanol-water (1:1, v/v) by increasing the flow-rate of the mobile phase stepwise from 1.0 to 2.2 ml min(-1) after 210 min. A 17.1mg 5-HMF with purity of 96.6% was also isolated for the first time.
Preview · Article · Jun 2007 · Journal of Pharmaceutical and Biomedical Analysis
[Show abstract][Hide abstract] ABSTRACT: Following preparative isolation and purification by high-speed counter-current chromatography (HSCCC), the collected fractions were generally analyzed by high-performance liquid chromatography (HPLC) to determine the relative purities of each fraction. Our paper reports for the first time a preparative isolation-purity detection hyphenated system: online coupling of HSCCC with high-performance liquid chromatography-diode array detection (HSCCC-HPLC-DAD). The introduction of online purity analysis in HSCCC has dramatically improved the efficiency of this technique by overcoming the drawbacks of post analysis in HSCCC isolation. The effluent from the outlet of HSCCC was splitted into two parts: one was collected, while the other was introduced directly into an HPLC-DAD system for purity analysis through a switch valve. Therefore, the purities of the obtained fractions from HSCCC were monitored, and fractions with high purities were collected. This strategy has been successfully demonstrated with the preparative isolation and purification of hyperoside from Hypericum perforatum (St. Jone's Wort); a model of TBE-300A HSCCC was used to isolate and separate hyperoside from H. perforatum with a two-phase solvent system composed of ethyl acetate-ethanol-water at the volume ratio of 5:1:5 (v/v) using online detection technique. The isolation was done in less than 3.5 h, and a total of 83.0-mg hyperoside at over 99.0% purity was yielded from 300 mg of the partially purified extract. This new strategy possesses general utility in the preparation of bioactive compounds from traditional Chinese medicine (TCM).
Preview · Article · Jun 2006 · Journal of Chromatography A
[Show abstract][Hide abstract] ABSTRACT: The bioavailability and pharmacokinetics of fluvoxamine maleate were examined in 18 healthy volunteers who received a single oral dose of fluvoxamine maleate in a new formulation in a randomized balanced 2 way crossover design. The analyte and internal standard were extracted from plasma samples by liquid–liquid extraction and chromatographed on a C18 analytical column. A Varian 1200L tandem mass spectrometer equipped with an electrospray ionization source was operated in the selected reaction monitoring (SRM) mode. The geometric means of AUC0-72h and Cmax of fluvoxamine maleate in the test and reference formulations were 2632.78±375.83 ng×h/mL vs 2683.83±431.51 ng×h/mL and 99.79±22.89ng/mL vs 101.15±24.46 ng/ml, respectively. The geometric means of other pharmacokinetic parameters (AUC0~∞, t1/2, tmax, and MRT) of fluvoxamine maleate in the test and reference formulations were 2829.85±390.16 ng×h/mL vs 2925.16±426.12 ng×h/ml, 15.22±2.54 h vs 16.53±2.80h, 6.4±1.3 h vs 7.1±1.0 h and 28.75±2.52h vs 29.83±3.20 h, respectively. These observations indicate that the two formulations for fluvoxamine maleate were bioequivalent and, thus, may be clinically interchangeable. The HPLC/MS/MS method for the quantification of fluvoxamine maleate in human plasma was approved to be highly sensitive and selective with, increased, throughput and met the needs for pharmacokinetic assays such as bioequivalence studies. (Supported by Fundamental Research Key Project founded by Science & Technology department of Shanghai, P. R. China, Grant NO. 03JC14005)
*Corresponding: Dr. Guorong Fan, No.325 Guohe Road, Shanghai 200433,
China, Tel (Fax): +86-21-2507-0388; email: email@example.com
[Show abstract][Hide abstract] ABSTRACT: High-speed counter-current chromatography (HSCCC) was applied to the isolation and purification of geniposide from Gardenia jasminoides Ellis. Analytical HSCCC was used for the preliminary selection of a suitable solvent system composed of ethyl acetate-n-butanol-water (2:1:3, v/v/v). According to the above solvent system, preparative HSCCC was successfully performed with the optimal solvent system composed of ethyl acetate-n-butanol-water (2:1.5:3, v/v/v) yielding 389 mg of geniposide at over 98% purity from 1g of the partially purified extract with 38.9% recovery in a one-step separation.
Full-text · Article · Jan 2006 · Journal of Chromatography A