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1.
Summary Octadecyl-porous glass was prepared and used as the packing for reversed-phase high-performance liquid chromatography. A mixture
of ginsenosides, saponins of ginseng was analyzed with detection at 203 nm. Ginsenosides Rf, Rg2, Rb1, Rc, Rb2, and Rd were separated with acetonitrile-water (27.5:72.5) as the mobile phase. A well-resoluted chromatogram of ginsenosides
Ro, Rg1 and Re was also obtained with acetonitrile-water (16.5:83.5). The whole separation was achieved in 12 min with a flowrate
of 1 ml/min. Calibration curves of ginsenosides Rb1, Rc, Rb2, Rd, Rg1 and Re were linear up to 5 μg. It can be concluded that the rapid and accurate analysis of ginsenosides is possible by the
described method. 相似文献
2.
Summary New column-packing materials specially designed for the HPLC analysis of basic compounds have been tested for the analysis
ofCatharanthus alkaloids. Mobile phase optimization was performed for each column tested. The influence of mobile phase pH, nature and content
of the organic modifier and salt concentration on retention, selectivity and resolution was studied. An important factor in
the separation proved to be the pH of the eluent, because of the widely different pK
a values of the analytes. Complete separation was easily achieved on ODS columns, but polymeric materials also gave acceptable
results.
Presented at the 21st ISC held in Stuttgart, Germany, 15th–20th September, 1996 相似文献
3.
Mixtures of ethanol, dichloromethane, hexane and acetone obtained according to a statistical design have been used to extract substances from Erythrina speciosa Andrew leaves for chromatographic fingerprinting. The plant extracts from each mixture were analyzed by HPLC-DAD providing UV–vis spectra for each chromatographic peak. These chromatograms and spectra for the design mixtures were then treated with principal component (PCA), Tucker3 and PARAFAC analyses. PCA indicated the existence of five different chromatographic fingerprints for the leave extracts depending on the solvent mixture composition. Different chromatographic peak areas were strongly correlated with the mixture proportions of acetone, dichloromethane and ethanol. Tucker3 and PARAFAC analyses were very useful for identifying simultaneous correlations between chromatographic peak areas, spectral band absorbances and solvent proportions. The acetone proportion was highly correlated with the area of the 3.69 min retention time peak and the spectral absorbances between 250 and 260 nm, consistent with the presence of natural polyphenols. The dichloromethane mixture proportion was strongly correlated with the 12.19 min chromatographic peak area and a single spectral absorbance at 201 nm. This spectral absorption is characteristic of the electronic structures of terpenes and alkaloids. 相似文献
4.
Summary Poppy capsules with a high alkaloid content are of great importance to the pharmaceutical industry, because approximately
35 000 tons of straw (capsule with short stem), 350 tons of straw concentrate, and 1000 tons of opium are used annually for
extraction of morphinane alkaloids.
The combined use of four different liquid chromatographic methods is proposed for determination of alkaloid content. In the
first, semi-quantitative, method screening is performed by multilayer overpressured-layer chromatography (MLOPLC) in which
142 samples are separated on silica as stationary phase within 5 s per sample. If the morphine content is >1.3% it is then
measured quantitatively by NPHPTLC (normal-phase high-performance thin-layer chromatography) combined with densitometric evaluation.
A second, quantitative, determination is always performed by means of a rapid RPHPLC (reversed-phase high-performance liquid
chromatography) method in which the separation time is less than 4 min per sample. If the difference between the alkaloid
content measured by use of the last two methods is >12% a confirmatory RPHPLC method with increased selectivity and analysis
time (15 min) must be used.
The high throughput strategy presented has been used for analysis of ca. 15 000 samples per year, per genotype. Systematic
selection, cross-breeding, and this analytical strategy with combined planar and column liquid chromatographic methods resulted
in the discovery of two new candidate cultivars with high morphine (ca. 2%) and thebaine (ca. 1.5%) content.
Presented at Balaton Symposium '01 on High-Performance Separation Methods, Siófok, Hungary, September 2–4, 2001. 相似文献
5.
M. A. Campanero B. Calahorra E. García-Quetglás M. Escolar J. Honorato 《Chromatographia》1998,48(7-8):555-560
Summary A sensitive liquid chromatographic assay for the quantitative determination of the opioid analgesic tramadol and its active
metabolite is described. Fluconazole was used as internal standard. The assay involved a singletert-butyl methyl ether extraction and LC analysis with fluorescence detection. Chromatography was at 30°C pumping an isocratic
mobile phase of acetonitrile-water (19∶81, v/v) containing 0.06M NaH2PO4 and 0.05M triethylamine, adjusted to pH 7.90, at 1 mL min−1 through a reversed-phase, 250×4 mm base-stable column. The limit of quantitation of tramadol and its active metabolite was
1 ng mL−1, only 0.5 mL plasma sample was required for the determination. The calibration curve was linear from 1–1000 ng mL−1. Intra and inter-day precision (C.V.) did not exceed 10%. Mean recoveries of 96.38% for tramadol and 96.62% forO-demethyltramadol with CVs of 0.43% and 1.46% were obtained. Applicability of the method was demonstrated by a pharmacokinetic
study on normal volunteers who received 100 mg tramadol intravenously. 相似文献
6.
Summary A chromatographic method has been developed for enrichment of methionine-bound sulfur in casein, for stable-isotope analysis.
Casein is precipitated from milk samples and cleaved by acid hydrolysis in 6m hydrochloric acid at 95 °C. The amino acids released are converted into theirN-acetyl derivatives by addition of acetic acid anhydride. After lyophilization,N-acetylmethionine is separated from the accompanying components on octadecylsilica by use of a gradient prepared from 0.02m formic acid and methanol. The fractions containingN-acetylmethionine are pooled and freeze dried. Procedures for hydrolysis and derivatization were optimized to furnish the
highest yields. The influence of the abundance ratio on the chromatographic separation is shown and discussed. From 1.0 g
casein 16.5 mgN-acetylmethionine were isolated. 相似文献
7.
Summary A semi-preparative high-performance liquid chromatographic procedure on 5-m silica was developed for the isolation of gram quantities of ethyltrans-5-iodo-trans-2-methylcyclohexane-1-carboxylate (B1) and ethyltrans-4-iodo-trans-2-methylcyclohexane-1-carboxylate (B2) for comparative evaluation as male Mediterranean fruit fly,Ceratitis capitata, attractants and for NMR studies. This procedure can also be used analytically to determine the content of B1 (the attractive isomer) in ceralure, the ethyl 4- and 5-iodo-trans-2-methylcyclohexane-1-carboxylate mixture. 1,1-Dimethylethylcis-5-iodo-trans-2-methylcyclohexane-1-carboxylate (A) and 1,1-dimethylethylcis-4-iodo-trans-2-methylcyclohexane-1-carboxylate (C) were isolated and converted to their ethyl esters, thus supplying the fourtrans-isomers of ceralure. 相似文献
8.
Summary A sensitive HPLC method for determination of paralytic shellfish poisoning (PSP) based on ion-pair chromatographic separation
of PSP toxins, post-column oxidation with periodic acid, and fluorescence detection has been used to determine toxin profiles
ofPyrodinium bahamense and several strains ofAlexandrium. The HPLC chromatograms revealed clear differences betweenPyrodinium bahamense andAlexandrium strains.
Presented at the 21st ISC held in Stuttgart, Germany, 15th–20th September, 1996. 相似文献
9.
Long L Song Y Wu J Lei L Huang K Long B 《Analytical and bioanalytical chemistry》2006,386(7-8):2169-2174
In our research into chlorophylls of marine dinoflagellates, chlorophyll a was separated rapidly from the hexane extract of Amphidinium carterae in three steps. The first step was silica gel column chromatography, where elution was performed with 0–50% ethyl acetate
in n-hexane. The second was high-speed counter-current chromatography using a two-phase solvent system consisting of n-hexane–ethyl acetate–methanol–water (5:5:5:1, v/v), and the third step was preparative reversed-phase high-performance liquid
chromatography using a solvent system of acetone–water (89:11, v/v). HPLC analysis showed that the purity of chlorophyll a from the second step was over 83%, and after the third it was over 99%. Thirty milligrams of chlorophyll a was isolated from a crude sample of 250 mg of chlorophylls, and its structure was identified by analyzing its MS, 1H NMR and 13C NMR spectra. 相似文献
10.
An HPLC method has been developed for the separation of valdecoxib and a degradation product consisting of α and β-N-lactosyl sulfonamide, i.e. α and β anomers (SC-77852). Best results were achieved with a Chromolith Performance RP-18e column (100 mm × 4.6 mm), macropore size 2 μm, mesopore size 13 nm, with an eluent of methanol:water containing a 1% solution of TEA (36:64 v/v), pH 7.4 (adjusted with 85% orthophosphoric acid), at 22 °C. Detection was at 220 nm. The method was validated for its selectivity, linearity, precision (repeatability) and robustness. Quantitation and detection limits were determined for both valdecoxib and SC-77852. Method robustness was further evaluated by performing 23 full factorial design experiments. The final step, optimisation of the variables, was performed using response surface design. The validated method was used for assay of valdecoxib and SC-77852 in Bextra® film-coated tablets. 相似文献
11.
Summary A commercial reversed-phase (RP) C18 HPLC column has been dynamically coated with the chiral selectorN
τ-n-decyl-l-spinacine and then loaded with copper(II) ions. Several racemic mixtures of underivatized amino acids and oligopeptides were
resolved on the column by chiral ligand-exchange chromatography. The most important experimental conditions affecting column
efficiency, retention, and selectivity (temperature and mobile phase flow rate and composition) were extensively investigated. 相似文献
12.
Summary Mizolastine (SL 85.0324) is a new antihistaminic H1 benzimidazole derivative which is excreted into urine almost completely metabolized; about 2% of the unchanged drug is excreted as conjugated compound which requires enzymatic deconjugation before analysis. Since the existing methods for plasma samples do not work on deconjugated human urine due to interferences, a new method was developed. The method is based on a diethyl-ether extraction of mizolastine and an internal standard from alkalinized urine. The ether extract is back-extracted with an aqueous buffer (pH=2.6), this extract is neutralized (pH=6.5) and an aliquot injected into a C18 pre-column where clean up and preconcentration take place. The analytes are then desorbed from the pre-column and transferred to the analytical column. The analytical column is a C18 type specially seactivated for basic compounds with an eluent of acetonitrile/phosphate solution (pH=4.5), 40/60, v/v, at a flow rate of 1 ml min–1. Detection is at 285 nm. The method is linear in the range 10–500 ng ml–1 with a lower limit of detection of 10 ng ml–1. The precision and accuracy, evaluated during intra-day and inter-day assays, are satisfactory for pharmacokinetic investigations. 相似文献
13.
The fruits of Poncirus trifoliatus Raf. (Rutaceae) have been used against allergic diseases for generations and still occupy an important place in traditional
oriental medicine. They have also been used to treat gastric and duodenal ulcers. Chemical analysis of extracts of Poncirus trifoliatus Raf. fruit at different stages of maturation revealed variations in the concentrations of flavonoids present. Fourteen flavonoids
(neoeriocitrin, narirutin, naringin, hesperidin, neohesperidin, neoponcirin, poncirin, naringenin, hesperetin, sinensetin,
nobiletin, heptamethoxyflavone, 5-O-demethylnobiletin, and tangeretin) and five amines (synephrine, octopamine, N-methyltyramine, hordenine, and tyramine) in extracts from the fruit of Poncirus trifoliatus Raf. were analyzed by HPLC with a C18 reversed-phase column. The concentrations of the four flavonoids naringin, poncirin, narirutin, and neoponcirin was maximum
during the first stage of growth and gradually decreased until the fruits were fully developed. The paper also discusses the
anatomical variations observed at different stages of development of the fruit. 相似文献
14.
N. Mulinacci C. Bardazzi A. Romani P. Pinelli F. F. Vincieri A. Costantini 《Chromatographia》1999,49(3-4):197-201
Summary
Hypericum perforatum L. is a spontaneous perennial herbaceous plant, widely distributed in Europe, Asia, Northern Africa, and North America. The
dried flowers or dried aerial parts are used to prepare the drug Hyperici Herba or St. John's Wort. Nowadays this drug is
largely used as a natural antidepressant; hypericin and hypericin-like substances are considered the main active ingredients.
In this work the hypericin and pseudohypericin content of hydroalcoholic extracts both of Hyperici Herba and ofHypericum perforatum L. dried flowers were measured by two techniques, TLC-densitometry with fluorescence detection and reversed-phase HPLC-DAD
(diode-array detection). The quantitative data obtained by applying these techniques were compared and the identification
of the main flavonoid constituents was performed by HPLC-DAD for characterization of the extracts.
The quantitative data obtained by use of the two techniques were in good agreement and statistical analysis of the findings
was indicative of the equivalence of the techniques. 相似文献
15.
‘Fufang Danshen tablet’ (FDT), made from Radix salvia miltiorrhiza and Panax notoginseng, is a widely used botanical drug derived from traditional Chinese medicine. Quantification of the active components of Radix salvia miltiorrhiza and Panax notoginseng is very important for regulation of FDT products. In this study HPLC hyphenated with ultraviolet (UV) detection and evaporative
light-scattering detection (ELSD) was used for simultaneous determination of nine active components (three salvianolic acids,
three tanshinones, and three saponins) of FDT products. Separation was performed on a 250 mm × 4.6 mm i.d., 5.0 μm particle-size,
C18 column with linear gradient elution. UV detection at 280 and 254 nm was used for detection of the three salvianolic acids
and the three tanshinones, respectively. ELSD was used for detection of the three saponins, which were difficult to analyze
by use of UV detection. The linearity of the calibration plots was excellent over the concentration ranges investigated (values
of R
2 were >0.99 for all the analytes) and recovery measured at three concentrations was between 92.2 and 107.7%. The validated
method was successfully used for simultaneous determination of these components in FDT products. 相似文献
16.
Nakamura S Wada M Crabtree BL Reeves PM Montgomery JH Byrd HJ Harada S Kuroda N Nakashima K 《Analytical and bioanalytical chemistry》2007,387(6):1983-1990
A sensitive semi-micro column HPLC method with peroxyoxalate chemiluminescence (POCL) detection and column switching has been
developed for simultaneous determination of 3,4-methylenedioxymethamphetamine (MDMA) and related compounds, for example 3,4-methylenedioxyamphetamine,
methamphetamine, and amphetamine, in hair. After digestion of the hair with 1 mol L−1 sodium hydroxide the compounds were extracted with n-heptane and derivatized with 4-(N,N-dimethylaminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole. A mixture of hydrogen peroxide and bis(2,4,5-trichloro-6-carbopentoxyphenyl)oxalate
in acetonitrile was used as post-column CL reagent. Calibration plots showed linearity was good (r = 0.999); detection limits were 0.02–0.16 ng mg−1 hair at a signal-to-noise ratio of 3. The precision of the method, as RSD (n = 5), in intra-day and inter-day assays was better than 5.0 and 6.9%, respectively. The proposed method was sufficiently
sensitive to detect low ng mg−1 levels of MDMA and related compounds in hair, and could be used for quantification of the compounds in hair samples from
patients treated in a chemical dependency unit. 相似文献
17.
The gaseous PVTx properties of ethyl fluoride (HFC-161) + 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) mixtures were measured at temperatures from 318.180 to 403.205 K and corresponding pressures from 961.3 to 3129.8 kPa using the isochoric method. The uncertainties in the present measurements were estimated to be ±1.5 kPa for pressure and ±6 mK for temperature. On the basis of the experimental PVTx property data, a truncated virial equation of state was developed for the binary HFC-161/227ea system. This equation reproduced the experimental data in the gas phase within ±0.164% in pressure and within ±0.178% in density. 相似文献
18.
Summary Inorganic buffers have been used to control the pH of a superheated water eluent for reversed-phase liquid chromatography.
Using a temperature gradient from 70–190 °C, the relative order of elution of a series of sulfonamides on a polystyrene-divinyl
benzene column was determined at pH 3, 7 and 11. The separations were compared with conventional reversed-phase separations
on polymer and ODS-bonded silica columns. The apparent pK
a values of selected sulfonamides at elevated temperatures were determined from their retention factors across in a range of
superheated buffers and the values were compared to those reported at room temperature. 相似文献
19.
Summary An analytical GC method was developed which uses a single packed column consisting of three packings in series prepared with the following liquid phases: dimethyl sulfolane, propylene carbonate, and silver nitrate. This system provides satisfactory resolution of mixtures of C1–C5 hydrocarbons and dimethyl ether obtained when converting methanol to gasoline. Due to the high capacity of the column it is possible to inject larger sample amounts permitting trace analysis. 相似文献
20.
《Journal of separation science》2017,40(13):2838-2848
An approach combining micellar electrokinetic chromatography fingerprinting with chemometrics was developed to evaluate the quality consistency of Lianqiao Baidu pills, which are traditional Chinese patent medicines composed of 19 herbs used mainly to treat skin ulcers, common cold, rheumatism, herpes, and constipation. The triangle optimization method was employed to choose a satisfactory background electrolyte, with the information index, I , as an objective function for assessing the capillary electrophoresis conditions. Then, under the optimal conditions, the micellar electrokinetic chromatography fingerprints of 28 batches of samples were established, and five marker compounds were quantitatively determined simultaneously. A limited‐ratio quantified fingerprint method was introduced to evaluate the chromatographic fingerprints both qualitatively and quantitatively. Principle component analysis revealed that the 28 batches of samples can be clustered according to different manufacturers. Moreover, the relationship between the fingerprint and the antioxidant activity was explored by orthogonal partial least‐squares regression, which provided critical medicinal efficacy information for quality control. The present study establishes a powerful and reliable method for monitoring the quality consistency of Lianqiao Baidu pill. 相似文献