摘要:

AbstractA high performance liquid chromatographic (HPLC) method for analysis of 4 free and 8 conjugated bile acids in submicromolar quantities in serum is described using precolumn derivatization with 4‐bromomethyl‐7‐methoxy‐coumarin (BMC) and fluorescence detection. Bile acids were extracted from serum with 0.4 M sodium bicarbonate, adsorbed onto a Sep‐Pak C18cartridge and eluted with methanol. The extract was derivatized with BMC in acetonitrile using 18‐crown‐6 crown ether as catalyst and the BMC labelled glycine conjugates and free bile acids were analysed using acetonitrile + methanol + water gradient elution and detection at 320/385 nm.Using a novel and simple approach, taurine conjugates were isolated by extracting the dried, derivatized material with water, in contrast to previous methods which required column chromatography cleanup to isolate the taurine conjugates prior to derivatization. The isolated taurine conjugates were then hydrolysed enzymatically, extracted, derivatized and analysed as free‐bile acids.Recoveries of individual bile acids varied from 83 – 96% for free and glycine conjugates and 72 – 83% for taurine conjugates. Coefficients of variation were in the range of 5.1 – 12.5%. In addition to the simpler and shorter procedure for taurine conjugates, this method has increased sensitivity over most other procedures and improved HPLC separation for the various bile acids and conjugates with equivalent recovery and reproducibility compared with ot

ISSN:0269-3879    

DOI:10.1002/bmc.1130040403

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

Abstractβ‐Hydroxypropionic acid‐ and hydroxyacetic acid‐uroporphyrin I have been isolated from the urine of a patient with congenital erythropoietic porphyria by reversed phase high performance liquid chromatography. The compounds were characterized by their chemical behaviour and confirmed by liquid secondary ion mass spectr

ISSN:0269-3879    

DOI:10.1002/bmc.1130040404

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractA sensitive and accurate reversed phase liquid chromatographic assay was developed for the determination of 6‐mercaptopurine (6MP) (the active metabolite of azathioprine) in human plasma. The assay involved extraction into acetonitrile and dichloromethane from plasma pretreated with 0.038 M of dithiothreitol solution. The residue was analyzed by isocratic chromatography on a C18analytical column with UV detection at 326 nm. The average extraction recovery of 6MP was 85%.The method has been applied successfully to the determination of 6MP and its metabolites in pharmacokinetic studie

ISSN:0269-3879    

DOI:10.1002/bmc.1130040405

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractHigh performance liquid chromatography (HPLC) with a TSK‐4000SW gel filtration column was used to compare envelope polypeptides from four strains of herpes simplex virus type 1 (HSV‐1). The chromatographic profiles demonstrated polypeptide variability among three clinical strains and the wild‐type F strain. Radioimmunoprecipitation of the HPLC fractions with polyclonal anti‐HSV‐1 followed by SDS‐polyacrylamide gel electrophoresis (PAGE) of the immunoprecipitates revealed molecular weight differences of various polypeptides in fractions from the area containing major peaks. This HPLC method could prove useful for the analysis of polypeptide polymorphism in clinical isolates of HSV‐1, as well as in

ISSN:0269-3879    

DOI:10.1002/bmc.1130040406

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe separation of the Hageman factor fragment (HFf) activity from human serum albumin by chromatography on Blue Sepharose CL‐6B is described. The complete separation cannot be achieved in a single chromatography step due to complex formation between HFf and albumi

ISSN:0269-3879    

DOI:10.1002/bmc.1130040407

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractA method for the determination of doxorubicin and daunorubicin in plasma is described. The plasma is injected directly into a loop column and then washed with water. After switching the injection valve, the sample is separated on a phenyl column using detection at 254 nm. The detection limit is 10 ng/mL, the coefficient of variation is 7% for 100 ng/mL of doxorubicin and 4% for 200 ng/mL of daunorubicin.

ISSN:0269-3879    

DOI:10.1002/bmc.1130040408

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractResolution of propranolol (PL) enantiomers in biological samples was accomplished by column switching high performance liquid chromatography using a short precolumn and an analytical column of ovomucoid chiral phase. Plasma, whole blood or tissue homogenate sample was directly injected into the precolumn, and PL was adsorbed on Butyl Toyopearl 650‐M. After column switching, the PL was backflushed and transferred to the analytical column (Ultron ES‐OVM) by the eluant. Fluorometric detection was carried out at λex= 297 nm and λem= 340 nm with a detection limit of 0.5 pmol (signal to noise ratio = 2). The recovery 98.8–103%), reproducibility (coefficient of variance less than 3%) and enantiomer resolution (separation factor 1.15) were satisfactory using as eluant 50 mM sodium dihydrogenphosphate (pH 4.6) containing 12% ethanol. The time course of elimination of PL enantiomers in rat or mouse blood and tissues was also

ISSN:0269-3879    

DOI:10.1002/bmc.1130040409

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractAn isocratic reversed phase high performance liquid chromatography procedure utilizing ultraviolet and fluorescence detectors linked in series is described for the analysis of cortisone (E), cortisol (F), corticosterone (B), 11‐deoxycortisol (S), 11‐deoxycorticosterone (DOC), androstenedione (A), testosterone (T), 17‐hydroxyprogesterone (17‐OHP), progesterone (P), estriol, estradiol, estrone, prednisone acetate and dexamethasone acetate in serum. Serum specimens were extracted with ethyl ether. The optimized mobile phase was methanol + tetrahydrofuran + water 26:18:56, v/v/v). A Shim‐pack ODS column was used. The recoveries were 80 to 103%. lntra‐ and inter‐day coefficient of variance were less than 8%. The detection limit is 0.5 pmol per injection volume for estriol, estradiol, E, F and B; 1 pmol for S, A, DOC and estrone; 2 pmol for T and 17‐OHP; and 4 pmol for P. Serum from normal subjects and patients with congenital adrenal hyperplasia due to 21‐ or l7‐hydroxylase deficiency were measured, as well as samples of maternal and u

ISSN:0269-3879    

DOI:10.1002/bmc.1130040410

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractTreatment of pyrimethamine with blood plasmain vitroyields a metabolite which is also produced when the drug is administered through intravenous injection in the rat. A thin layer liquid chromatographic method for quantitative and qualitative determination of pyrimethamine and its metabolite in plasma and biological tissues is described.

ISSN:0269-3879    

DOI:10.1002/bmc.1130040411

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractA method for the determination of lorazepam in rat brain is described using liquid/liquid and solid‐phase extraction, followed by high performance liquid chromatography. After addition of chlordiazepoxide as the internal standard, 100 mg brain tissue was homogenized and incubated with alkaline protease. Lorazepam and chlordiazepoxide were extracted three times with toluene. After treatment through a C 18‐Bond Elut column, lorazepam and chlordiazepoxide were analyzed isocratically on a reversed‐phase column with a mobile phase consisting of methanol + 0.025 M sodium phosphate buffer (66:34, v/v). The eluted drugs were monitored by their absorption at 240 nm. The sensitivity limit of this method was 10 ng of lorazepam per 100 mg of brain tissue sample. The standard curve was linear over the range of 20 to 200 ng lorazepam. The coefficient of variation for day‐to‐day precision established by 21 replicate analyses was 4.5

ISSN:0269-3879    

DOI:10.1002/bmc.1130040412

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY