高效液相色谱法测定硫酸沙丁胺醇

利用高效液相色谱仪-电子捕获检测器(HPLC-ECD)测定了市售片剂硫酸沙丁胺醇的含量.结果表明,利用HPLC-ECD技术测定硫酸沙丁胺醇的线性范围为0.944~33.8mg·L-1(r=0.999 6);回收率为99.0%~107.8%(RSD≤4.6%).该法可用于测定片剂的硫酸沙丁胺含量.     

Ultra-fast high-performance capillary sodium dodecyl sulfate gel electrophoresis of proteins

An ultra-fast analysis of proteins, based on sodium dodecyl sulfate (SDS)-mediated gel electrophoresis was developed, in which protein molecular mass standards ranging from M_r 14 200 to 94 700 were separated within 3 min. A 50 μm diameter uncoated fused-silica capillary column and a high field strength are used. The effects of the SDS concentration in the separation gel buffer and in the sample buffer on the resolution of protein test mixture were studied. The influence of the heat treatment of the sample prior analysis is also discussed.     

Determination of methylprednisolone in rat tissue by high-performance liquid chromatography

Methylprednisolone was determined in various types of rat tissue following an intravenous injection of methylprednisolone sodium succinate. Two modes of tissue work-up were investigated: digestion with subtilisin Carlsberg, a proteolytic enzyme, and homogenization with methanol. The final determination was by reversed-phase high-performance liquid chromatography with dexamethasone as internal standard. The extraction yields of methylprednisolone and dexamethasone from tissue homogenate and the extraction yield of methylprednisolone after incubation with viable tissue were determined. The experiments show that methylprednisolone and the internal standard are extracted in similar yields from tissue homogenates and that methylprednisolone can be recovered in a good yield after incubation with viable tissue, provided that the tissue does not have a high metabolic activity. There was a good agreement between the analytical results from the two different types of tissue work-up. The method of analysis proved feasible for pharmacokinetic work.     

Determination of apigenin in rat plasma by high-performance liquid chromatography

Apigenin (4′,5,7-trihydroxyflavone, AP) belongs to a less-toxic and non-mutagenic flavone subclass of flavonoids, the biotransformation and metabolism of which have been little studied until now. Therefore, this study is focussed on the determination of AP in free form. AP was administered to rats via the i.p. route (25 mg kg⁻¹) and then the blood was collected at 10, 15, 30 and 45 min after injection. Methanol was used for rat plasma deproteinization. The HPLC assay (mobile phase, 2% formic acid–acetonitrile–methanol, 40:35:25, v/v; flow-rate, 1 ml min⁻¹; UV detection at 349 nm) for AP determination was validated and used for the quantification of AP in rat plasma. The unknown concentration was calculated from the equation obtained by the least-squares regression analysis (y=0.521x+1.130, r²=0.998). The highest concentration of AP in plasma was found to be 30 min after injection. The concentration profile of AP obtained here may contribute to until known results about AP metabolism. They could be applied to other studies of AP or related flavonoids because of favourable effects on human health.     

Determination of traces of sodium alkylbenzenesulphonate by high-performance liquid chromatography. Application to water

Summary For the trace determination of sodium alkylbenzenesulphonate (ABS) by HPLC the following conditions were employed: Shimadzu ZORBAX SIL Column (5 m, 4.6 mm i.d. x 150 mm) as stationary phase, 0.2% ammoniaethanol (v/v) as mobile phase, UV detector at 225 nm, injection volume 12 l. The chromatograms of ABS were simple and sharp (detection limit of ABS 0.02 g in 12 l of ethanol). The calibration curves of ABS were linear in a concentration range of 0.03 0.3 g in 12 l of ethanol. In the case of linear sodium dodecylbenzenesulphonate positive errors of 1 4% were caused by non-ionic surfactants or laurylsulphate (6 times excess), 10 50% positive errors were caused by 2 6 times excess of household detergents.Standard water samples containing ABS were treated with a weak base anion-exchange resin, the adsorbed ABS were eluted, and then determined either by HPLC or by the methylene blue spectrophotometric method. Recoveries of ABS in water were about 92 107% by HPLC.

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Bestimmung von Spuren Natriumalkylbenzolsulfonat mit Hilfe der HPLC. Anwendung auf Wasser

Zusammenfassung Für die Spurenbestimmung von Natriumalkylbenzolsulfonat (ABS) durch HPLC werden die folgenden Bedingungen empfohlen:Shimadzu ZORBAX SIL (5 m, 4,6 mm x 150 mm) als stationäre Phase, 0,2% Ammoniak/Ethanol als mobile Phase, UV-Detektor bei 225 nm, Injektionsvolumen 12 l. Die erhaltenen Chromatogramme sind einfach und scharf (Nachweisgrenze 0,02 g in 12 ml Ethanol). Die Eichkurven sind im Konzentrationsbereich von 0,03–0,3 g in 12 l Ethanol linear. Im Falle des linearen Natriumdodecylbenzolsulfonats werden bei Anwesenheit von nicht-ionischen oberflächenaktiven Substanzen oder von Laurylsulfat in 6fachem Überschuß positiver Fehler von 1–4% erhalten; bei 2–6fachem Überschuß von Haushaltswaschmitteln ergeben sich positive Fehler von 10–50%.Standard-Wasserproben werden zunächst einer Behandlung mit einem Anionenaustauscher unterzogen, die adsorbierten ABS eluiert und durch HPLC oder nach der Methylenblaumethode analysiert. Wiederfindungsraten liegen bei 92–107%.

     

Determination of 2,3-benzodiazepine derivatives in rat plasma by high-performance liquid chromatography.

A simple high-performance liquid chromatographic method with ultraviolet detection at 240 nm for determination of a novel AMPA/kainate antagonist 1-(4'-aminophenyl)-3,5-dihydro-7,8-dimethoxy-2,3-benzodiazepine (2,3-BZ 6), and its derivatives in rat plasma is described. The procedure involves a fast extraction of the drugs from the plasma spiked with an internal standard. The samples are applied to a pre-packed glass column and drugs are eluted using ethyl acetate. A linear response was observed over the examined concentration range. The lower limit of detection of 2,3-BZ 6 was 5.5 ng/ml. The assay has been used to determine the time course of plasma levels of the 2,3-benzodiazepine derivatives in Sprague-Dawley rats.     

Separation of proteins by consecutive sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis and reversed phase high performance liquid chromatography

A procedure for the preparative separation of proteins was developed by using consecutively sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (SDS-PAGE) and reversed phase high performance liquid chromatography (HPLC). The proteins were separated by SDS-PAGE and afterwards extracted from the gel. The extracted proteins were separated from SDS and other small molecular weight contaminants on a Fractogel TSK HW-40 (F) column in acidic aqueous acetonitrile. The proteins eluted from the Fractogel column were fractionated by HPLC. The identity and purity of the recovered proteins was confirmed by SDS-PAGE analysis.     

Determination of thiamine by high-performance liquid chromatography

High-performance liquid chromatographic methods for the determination of thiamine (vitamin B1) in foodstuffs or biological tissues and fluids are outlined and discussed. The methods are often similar and interchangeable, sample extraction and clean up procedures being the major difference. Most of the methods use either ultraviolet or fluorescence detection. Fluorescence detection requires either precolumn or postcolumn oxidation of thiamine to thiochrome. A number of methods are recommended and problems with standardization are emphasized.     

Determination of aprotinin by high-performance liquid chromatography

Summary A highly accurate and reproducible method for the determination of aprotinin (bovine pancreatic trypsin inhibitor) by HPLC is described. In the experiments, the relative standard deviation was 1.2% and detection limit 1 FIP-U cm^–3. Also, the method is quick and selective and active ingredients from difference source correlate well with enzymatic method. Analyses at different laboratories can be compared directly.     

Analysis of cellulase proteins by high-performance liquid chromatography

A new procedure using high-performance liquid chromatography for the rapid separation of cellulase proteins is described. The cellulase components of Trichoderma reesei are fractionated on a DEAE anion-exchange column using a phosphate buffer at pH 6.2. Activities of the individual components obtained from T. reesei QM6a, a wild strain, and several mutant strains have been determined. Each system examined contained beta-glucosidase, at least two exo-beta-1,4 glucanases and five endo-beta-1,4 glucanases with the endo-beta-1,4 glucanases accounting for 20--36% and the exo-beta-1,4 glucanases for 64--80% of the soluble protein.     

Determination of danshensu in rat plasma and tissues by high-performance liquid chromatography

A systematic study on pharmacokinetics and tissue distribution of danshensu (one of the major active components from Salvia miltiorrhizae) is conducted using a rapid and sensitive high-performance liquid chromatographic (HPLC) method. Before HPLC analysis, biological samples are pretreated with a liquid-liquid extraction. Separation of danshensu and internal standard is achieved on an Agilent Zorbax C18 column with a mobile phase made up of acetonitrile and 0.05% trifluoracetic acid at a flow rate of 0.8 mL/min. The calibration curves in plasma and tissues are linear in the given concentration ranges, with r2 no less than 0.99. The intra-day and inter-day relative standard deviations in the measurement of quality control samples are less than 15%, and the accuracies are in the range of 86-115%. The recoveries of danshensu in plasma and tissues are among 80% to 118%. Meanwhile, the multi-peaks in pharmacokinetic profiles are observed. The method is successfully applied to the pharmacokinetics and tissue distribution study of danshensu after a single oral administration of 50.0 mg/kg sodium danshensu to rats.     

Determination of atractylenolide II in rat plasma by reversed-phase high-performance liquid chromatography

A method for quantitative determination of atractylenolide II in rat plasma using reversed-phase high-performance liquid chromatography (RP-HPLC) coupled with UV spectrometry was established. From a variety of compounds and solvents tested, atractylenolide III was selected as the internal standard (IS) and ethyl acetate was found to be the best solvent for extracting atractylenolide II from plasma samples. RP-HPLC analysis of the extracts was performed on an analytical column (DIKMA ODS, 150 x 4.6 mm; i.d., 5 microm) equipped with a security guard pre-column system. There was good linearity over the range 0.05-5.0 microg/mL (r > 0.99). The recoveries were more than 90.0% in plasma, and the intra- and inter-day coefficients of variation were less than 10.0% in all cases. The limit of detection (LOD) was 0.025 microg/mL and the lower limit of quantification (LLOQ) was 0.05 microg/mL. The RP-HPLC method was applied to quantitate atractylenolide II in rat plasma within 24 h in a pharmacokinetics study where experimental rats received a single dose of atractylenolide II (60 mg/kg).     

Determination of metformin in plasma by high-performance liquid chromatography.

A high-performance liquid chromatographic method for the determination of metformin, an oral antidiabetic agent, in plasma is described. Plasma samples containing the internal standard, phenformin, are eluted through Amprep extraction columns before injection into the chromatographic column, packed with microBondapak phenyl. The eluent is monitored at 236 nm. At a mobile phase flow-rate of 1.35 ml/min, the retention times of metformin and phenformin are 2.8 and 5.6 min, respectively. The intra-day coefficients of variation are 1.5 and 4.3% at metformin concentrations of 0.05 and 1 mg/l, respectively.