摘要:

AbstractThe increased attention on the therapeutic implications of stereoisomerism has provided an impetus for the development of analytical methods for enantiomeric separation. The indirect method of separation of enantiomers as diastereomers using high performance liquid chromatography (HPLC) has emerged as an efficient and versatile approach. This is due mainly to the availability of numerous chiral derivatization reagents (CDRs). This article reviews CDRs useful for the development of an indirect HPLC method using ultraviolet, fluoresence and electrochemical detection. In addition, factors crucial for the development of the indirect method are discussed.

ISSN:0269-3879    

DOI:10.1002/bmc.1130060402

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractA study has been carried out on 10 patients with ovarian cancer treated by intraperitoneal mitoxantrone. The serum concentration was determined by high performance liquid chromatography with spectrophotometric detection. The extracted analyte on the cartridge was injected and eluted on‐line into the analytical column by the mobile phase. This improved the signal and sample processing rate, without significant loss in analytical performance. Excellent linearity (r>0.9994) was observed for the calibration curve over the range 1–2000 ng/mL, along with a precision within‐day and between‐day estimated as 1.5% and 5.6%, respectively. Sensitivity was an order of magnitude higher than that of the comparison method. From a clinical point of view, these preliminary results have shown that intraperitoneal administration is more beneficial than intravenous therapy. Low serum levels (1–30 ng/mL) with a maximum at the first or second hour are

ISSN:0269-3879    

DOI:10.1002/bmc.1130060403

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractTwo enzymes, phosphoglycerate mutase and peroxidase, were purified by using an immobilized metal ion adsorbent for the removal of unwanted proteins. The mutase was obtained pure from a single column, whereas the purification of peroxidase required the use of a thiophilic adsorbent in a tandem. The capacity was 2.5 mg pure peroxidase per mL gel.

ISSN:0269-3879    

DOI:10.1002/bmc.1130060404

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe metabolism of ethimizol in the human body has been investigated. Focus was on the detection and demonstration of the regioselective pathway of metabolic demethylation of ethimizol by determining the presence of the corresponding metabolites in blood, saliva and urine. Isolation, purification and identification of the metabolites present in the biological samples was achieved by applying a combination of the following methods: solid phase extraction, high performance liquid chromatography, high performance thin layer chromatography, nuclear magnetic resonance and mass spectrometry. The suggested chemical structures were definitely established by comparing the physicochemical characteristics of the ethimizol metabolites obtained from the individual biological fluids with the characteristics of synthetized authentic derivatives.

ISSN:0269-3879    

DOI:10.1002/bmc.1130060405

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractA method for the extraction and quantification by high performance liquid chromatography (HPLC) of non‐labelled benzodiazepines partitioned into biological membranes has been developed. The benzodiazepine (BZD) was partitioned in a synaptosomal membrane–buffer system. The membranous pellet was separated by centrifugation and from this pellet, previously submitted or not to a proteolytic treatment and resuspended in the same buffer, the BZD was extracted by the addition of the proper volume of ethyl acetate, i.e. that capable of extracting at least 99.5% of the total drug in the aqueous phase. Optimal conditions for maximum proteolysis were: incubation of membranes at a final concentration of 1 mg protein/mL in the presence of 0.08 mg of Protease type I per mL for 90 min. at 45°C. Although the efficiency of the proteolysis was demonstrated not only by kinetic but also by electrophoretic evidence, recovery of BZD in the organic solvent was not increased by the enzymatic treatment at a mass BZD/protein ratio in the range 4–4.6 10−5μg BZD/mg protein. For the HPLC quantification a reversed phase ODS column was used with methanol: water (1:1) plus 3.5% acetic acid as the mobile phase at a constant pressure and 1 mL/min flow rate. The UV detector was calibrated at 265 nm. Calibration curves were constructed by plotting peak height or peak area vs. nmoles BZD and adjusted to straight lines by a regression analysis by the least squares method. The peak height was selected as the detection method. Intra‐ and inter‐assay precision did not exceed 10% and the total reco

ISSN:0269-3879    

DOI:10.1002/bmc.1130060406

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractA reversed phase high performance liquid chromatographic method for the simultaneous determination of pseudouridine (PU) and creatinine (Cr) in urine is described. The mobile phase was 0.01 mol phosphate buffer (pH 6.1) containing 2.5 mmol octanesulphonic acid as the ion pairing agent. UV detection was set at 250 nm. Variation in pH value affected the retention time of PU and Cr significantly; Their separation from interfering peaks was also affected. The recoveries of PU and Cr were 89.93% and 90.35%, respectively. The standard deviation of the method for PU was 48.69 ± 0.063 (nmol/μmol Cr, mean ± SD,n= 5). The urine samples from 233 normal children of different ages and 119 patients with leukaemia were analysed by this method. The normal reference value was appraised by comparison with the percentage of immature cells in the bone marrow. The results showed that the sensitivity of the method was 94.12%, the specificity was 95.86%, the accuuracy was 95.50%, the positive predictive value was 82.05% and the negative predictive value was 98.78%. The method can be used to evaluate the state of the leukaemia, and to monitor the effect of treatme

ISSN:0269-3879    

DOI:10.1002/bmc.1130060407

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe Hageman factor fragment (HFf) concentrate was prepared from acetone and dextran sulphate activated human plasma by chromatography on a CM‐Sephadex column. The preparation was free of the main kallikrein inhibitors—Cl‐inactivator, α2‐macroglobulin, antithrombin III and α1‐antitrypsin. The HFf concentrate can serve as an activator of prekallikrein in pat

ISSN:0269-3879    

DOI:10.1002/bmc.1130060408

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe separation of tetracycline and amino glycopeptide antibiotics was achieved on silica gel thin layers. Tetracycline antibiotics were resolved on a Co+2(1.0%) impregnated silica gel layer using ethanol:acetic acid: water (10:6:6, v/v/v) as the mobile phase. Amino glycopeptide antibiotics were separated on an untreated silica gel layer using the mobile phasen‐butanol: formic acid: water (6:5:7, v/v/v). The spots of these antibiotics were located by exposing the chromatoplate to iodine vapour

ISSN:0269-3879    

DOI:10.1002/bmc.1130060409

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractA sensitive method for the determination of hyoscine (scopolamine) in urine is described. After concentration and “clean‐up” on C18and CN solid phase extraction columns, hyoscine was quantified by high performance liquid chromatography with coulometric detection (oxidation at +0.9 V). The limit of detection was 5 ng per sample and the precision for 5 mL samples containing 2 ng/mL was 12.3%. The method was applied to urine samples collected from 12 volunteers wearing Scopoderm TTS patches. The mean excretion rate of unmetabolized hyoscine was 0.45 μg/h and 87% of the total hyoscine was present as conjugates. Apohyoscine (aposcopolamine) was identified as a urinary metabolite. The significance of this with regard to hyoscine assays is dis

ISSN:0269-3879    

DOI:10.1002/bmc.1130060410

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractZn‐metallothioneins (MT‐1 and MT‐2) were isolated and purified from Wistar rat liver induced by subcutaneous injection with cadmium chloride over a short time. Instead of Sephadex G‐50 and DEAE Sephadex A‐50, new chromatographic media produced by Pharmacia, Sephacryl S‐200, S‐100 and DEAE Sepharose Fast Flow were used in the purification of metallothioneins. The time required for purification with the new method was only 1/3 that required with the usual method and had the same purification effect and rate of recovery. The number of mercapto groups measured with modified Ellman's reagent and cysteine as standard is 20 in MT molecules. Zn and Cd concentrations in each fraction were measured by single sweep polarography rather than atomic absorption spectrophotometry. MT‐1 and MT‐2 contained 6 gram atoms of zinc, but no cadmium. Purified MT‐1 and MT‐2 were shown by high performance liquid chromatographic analysis to be highly homogeneous and had an amino acid composition sim

ISSN:0269-3879    

DOI:10.1002/bmc.1130060411

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY