ISSN:0269-3879    

DOI:10.1002/bmc.1130080502

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractFluorescence and chemiluminescence detection were compared for HPLC analysis of the fluorescamine derivative of histamine. The kinetic behaviour of the chemiluminescent response for the derivative was characterized in a static system. An HPLC method was optimized for the derivative using fluorescence detection. Fluorescence detection was linear over the range of 166–1666 pg on column for the fluorescamine–histamine derivative with a limit of detection of 13 pg on column. Using a detector designed for optimal use with chemiluminescence, the chemiluminescence response of the fluorescamine derivative was linear over a range of 1.66–16.6 ng on column with a limit of detection of 1.0 ng on column. These results exemplify a case in which superior detectibility is provided by fluorescence over chemiluminescence, and contradicts many reports comparing fluorescence to chemiluminescence. The authors conclude that chemiluminescence should be considered when indicated by conditions established for separation that are favourable for the observation of chemiluminescence. These conditions include sufficiently low excitation energies corresponding to an excitation maximum greater than 400 nm, favourable dipole character of analytes, mobile phases of high organic content, and an appropriate pH of the mobile

ISSN:0269-3879    

DOI:10.1002/bmc.1130080503

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractA polymer immobilizedo‐nitrobenzophenone reagent was prepared for analysis of amine drugs in micellar electrokinetic chromatography (MEKC). A model compound, propylamine, was used to characterize the reagent's performance in MEKC. Derivatizations were performed on the CE instrument with reagent in the sample vial. The yielded derivative was directly sampled from the reaction mixture, and directly injected onto the MEKC system. The derivatization reagent was also applied to the derivatization ofn‐alkyl amine mixtures and amino acids. The method was validated for adamantanamine in urine and amino acids. The method was validated for adamantanamine in urine and in plasma by single‐blind spike analysis. Precisions and accuracies for all samples were less than 6.0% for urine samples and 10% for plasma samples. The procedure was a direct injection technique requiring minimal sample preparation for the analysis of drugs in biof

ISSN:0269-3879    

DOI:10.1002/bmc.1130080504

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractA high‐performance liquid chromatographic method for the determination of amiloride in airway surface liquid is described. It involves extraction of the drug with methanol from filter paper on which the sample is absorbed and chromatography on a Zorbax Rx column; the mobile phase is 25% acetonitrile in 0.05Mphosphate buffer; detection by fluorescence at 360/420 nm. Triamterene is used as an internal standard. The range of the assay is 2.0–2033.4 ng/sample, with adequate precision and accuracy. A power curvey=axbbest describes the relationship between the peak‐height ratio and concentration. Recovery of amiloride is non‐linear, probably due to an adsorption process. Accuracy of the assay at lower amounts may be affected by the choice of filter paper a well as by presence of endogenous plasma components. The assay was used to measure amiloride amount in airway surface liquid after administration of 2.5 and 4.5 mg of nebulized am

ISSN:0269-3879    

DOI:10.1002/bmc.1130080505

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractA high‐performance liquid chromatographic (HPLC) assay method has been developed for the quantitative determination of iothalamate andp‐aminohippuric acid (PAH) concentrations in serum and urine samples in the male rat. Glomerular filtration rate (GFR) was measured as clearance of iothalamate, while effective renal blood flow (ERBF) was measured as clearance of PAH. The method is simple, rapid and sensitive and detects iothalamate and PAH in rat serum and urine following administration of bolus doses and continuous infusions of iothalamate and PAH. Samples of serum and urine were deproteinized with two volumes of acetonitrile containing the internal standard, and an aliquot chromatographed on a C18 reversed‐phase column. The mobile phase was comprised of 0.1Msodium phosphate with 1.2 mMtetrabutylammonium phosphate: methanol, 85:15 (v/v), at a flow rate of 1.0 mL/min. The analytical column eluate was monitored with a UV detector at 254 nm with quantitation achieved using peak‐height ratios. The precision of the method was 6.6 and 3.6% for iothalamate in serum and urine, and 5.6 and 4.9% for PAH in serum and urine, respectively. The lower limit of quantitation was 0.63 μg/mL for iothalamate and 1.25 μg/mL for PAH in serum, and 3.1 μg/mL for iothalamate and 1.5 μg/mL for PAH in urine. Recovery of iothalamate from serum and urine was 99.9 and 93.5%, respectively. Recovery of PAH from serum and urine was 99.8 and 92.6%, respectively.The present study demonstrated that non‐radioactive iothalamate and PAH can be measured simultaneously using a HPLC assay to measure GFR and ERBF in

ISSN:0269-3879    

DOI:10.1002/bmc.1130080506

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractA sensitive and selective liquid chromatographic procedure to quantitate the deflazacort metabolite 21‐hydroxy‐deflazacort (DF‐21OH) in human plasma was developed and validated. DF‐21OH and fludrocortisone acetate (internal standard, IS) were isolated from human plasma (2 mL) by solid‐phase extraction onto C‐18 cartridges. Potential interferences were selectively removed and analytes were eluted with ethyl acetate. Following evaporation, the residue was reconstituted for HPLC analysis. Separation was achieved by gradient elution using a 5 μm YMC Basic column (2.0 × 100 mm) with mobile phases consisting of 20% methanol and 50% acetonitrile in 50 mMphosphate buffer (pH 3) at a temperature of 50°C. Flow rate was maintained at 0.3 mL/min., and analytes were quantified spectrophotometrically at 246 nm.The assay was validated over the range 1.0 to 500 ng/mL DF‐21OH. Calibration curves were prepared using a weighted (1/concentration) nonlinear quadratic regression algorithm. Peak‐height ratios were proportional to the amount of DF‐21OH added to plasma. Assay precision (%RSD) ranged from 4.2 to 11%, with a corresponding assay accuracy (% relative error) of ±2.8%. Absolute recovery of DF‐21OH from plasma was 78–86% over the concentration range. The minimum quantit

ISSN:0269-3879    

DOI:10.1002/bmc.1130080507

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractA multipurpose fluidized‐bed receptor‐affinity purification system based upon the biological recognition between an immobilized receptor and its soluble protein ligands is described. The fluidized affinity sorbent consists of a soluble form of interleukin‐2 receptor chemically bonded to an aldehyde derivative of controlled pore glass beads, which have a pore diameter of 1000 Å and a particle density of 1.2–1.3 g/mL. The fluidized‐bed separation device used in this study consists of a specially designed column fitted at the inlet end with a perforated distributor plate covered with a screen and the top outlet with an adjustable piston. The fluidized‐bed consisting of a loose gel matrix permits the unimpeded passage of cell debris and particulate matter, while the target protein is captured by the affinity beads. Purification of the humanized‐anti‐Tac monoclonal antibody is used as a model system to determine the operational parameters. Also, fluidized‐bed receptor‐affinity chromatography has been successfully employed in the purification of recombinant interleukin‐2 and single chain anti‐Tac(Fv)‐Pseudomonasexotoxin immunotoxin from unclarified inclusion body extracts. Overall, fluidized‐bed receptor‐affinity chromatography is found to be a productive affinity method suitable for the purification of recombinant human inter

ISSN:0269-3879    

DOI:10.1002/bmc.1130080508

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractAn immunoaffinity capillary electrophoresis technique has been developed for the analysis of cyclosporin A in human tear fluid following topical application of the drug. The technique combines the selectivity of immunoaffinity separation with the high‐resolution of capillary electrophoresis by immobilizing monoclonal antibody fragments directly onto the internal surface of the capillary. This technique was used to measure cyclosporin levels in tears obtained from corneal transplant patients during normal and drug toxicity episodes in the course of their treatment. Comparison of this technique with HPLC detection of cyclosporin in tears showed a good correlation, with the immunoaffinity CE technique having the advantage of being able to simultaneously detect toxic metabolites of cyclosporin in the same sampl

ISSN:0269-3879    

DOI:10.1002/bmc.1130080509

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

摘要:

AbstractA quantitative analytical method for the determination of a new thromboxane synthetase inhibitor (CGS 22652) in human plasma has been developed using high performance liquid chromatography (HPLC). The drug and internal standard (CGS 23298) were extracted with methylene chloride at pH 4.8. Separations were achieved by reversed phase chromatography using a mobile phase consisting of acetonitrile: 0.01Mcitrate/phosphate buffer (pH 3.5): methanol: tetrahydrofuran (45:45:9:1, v/v/v/v/), on a 5 μm C18column at a flow rate of 1.0 mL/min. Plasma standard curves were linear from 50 to 2000 ng/mL, with recovery of the drug being greater than 94% at all concentrations. The method was validated over a concentration range of 50 to 2000 ng/mL, with a limit of quantification of 50 ng/mL.The method was successfully applied to the analysis of clinical samples from a single‐dose safety and tolerability study conducted in healthy male voluntee

ISSN:0269-3879    

DOI:10.1002/bmc.1130080510

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY

ISSN:0269-3879    

DOI:10.1002/bmc.1130080511

出版商:John Wiley&Sons, Ltd.    

年代:1994

数据来源: WILEY