摘要:

An empirical equation has been developed to evaluate chromatographic separation efficiency. This equation can be expressed as the product of a “separation” term, a “capacity” term and an “alignment between peaks” term. It can be shown that this equation is insensitive to other column or separation parameters. Its sensitivity depends only upon the resolution between peaks. This in turn allows the linking of the equation with any column or separation parameter during the optimization process as a response function. The utility of this equation has been extensively tested with the aid of computer-simulated overlapping peaks. This method is applicable to any separation technique that is based upon separation of compounds due to differences in partitioning between the stationary and mobile phases (column chromatography, HPLC, counter-current distribution, etc.). This equation can also be used to evaluate the quantity of each separated or overlapped compound giving a true picture of separation efficiency.

ISSN:1082-6076    

DOI:10.1080/10826079608001917

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A size exclusion liquid chromography (HPSEC) method using refractive index (RI) and photodiode array (PDA) detectors and a BASIC calculation program was developed for high molecular weight contaminant determination in the C15linear paraffin-based cold rolling oil. Eight laboratory standards were analyzed to determine the new HPSEC/RI calibration factor for the C15linear paraffin rolling oil. Three contaminants and thirteen standard solutions were evaluated to establish calibration curves. The HPSEC/RI/PDA method will quantitatively determine the concentrations of polyisobutylene-based hydrodynamic backup bearing lubricant, mist-applied extreme pressure gear oil for the workroll bearing and antiwear hydraulic oil in the cold rolling oil. Deviations for backup bearing lubricant, workroll bearing lubricant and hydraulic oil are approximately 3%, 4% and 7% of the contaminant concentration, respectively.

ISSN:1082-6076    

DOI:10.1080/10826079608001918

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A simple extraction and analytical protocol was developed to assay cephalotaxine, harringtonine, and homoharringtonine from callus and root cultures ofCephalotaxus harringtonia.The process involves extraction by methanol followed by partitioning between 0.5% ammonium hydroxide and chloroform. The chloroform fraction recovered greater than 90% of all three alkaloids. This fraction was concentrated to dryness, resuspended in methanol and analyzed by high pressure liquid chromatography using a UV detector.

ISSN:1082-6076    

DOI:10.1080/10826079608001919

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

With RP-HPLC, an optimum gradient elution was achieved for separation of 15 chlorophenol positional isomers. Recoveries were satisfactory. The lowest detection limit is 5 × 10−10g. This method is suitable for determining these substances in environmental samples. The relationship between Capacity Factor (k′), Total Surface Area (TSA), and Molecular Connectivity Index (1x,1xv) of chlorophenol congeners was studied, which is reported here for the first time.

ISSN:1082-6076    

DOI:10.1080/10826079608001920

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

An ion interaction method is presented for the simultaneous separation of herbicides belonging to different structural classes. Phenylurea-, triazine- and phenoxyacid derivatives are considered and the method is applied in the analysis of typical Italian soils characterized by different composition.

ISSN:1082-6076    

DOI:10.1080/10826079608001921

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A simple isocratic reversed phase HPLC method for the determination of tranylcypromine sulfate (TCP) is described. The column used is Symmetry C18(Waters Corp., Milford, MA, USA) and the mobile phase consists of 50 mM KH2PO4(pH 4.55):methanol:water (20:10:70). Tranylcypromine sulfate is monitored by U.V. detection at 264 nm. The calibration curve of tranylcypromine sulfate is constructed over the range 25 nmol – 375 nmol/mL with a correlation coefficient 0.999. The method is specific and sensitive with a lower limit of detection 5 nmol/mL, the intra-assay and inter-assay relative standard deviation were below 10%. The validated assay procedure was applied to determine the tranylcypromine sulfate in urine and also to evaluate TCP in pharmaceutical preparation. Detailed methodology and the advantage of this C18reversed phase is presented.

ISSN:1082-6076    

DOI:10.1080/10826079608001922

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Racemic indenolol was resolved into its individual enantiomers by high performance liquid chromatography (HPLC) using a commercially available cellulose tris (3,5-dimethylphenyl carbamate) chiral stationary phase, known as Chiralcel OD. Indenolol contains two positional isomers, giving it a total of four enantiomers. The enantiomeric ratio was validated and peak identification for each enantiomer was established according to their optical rotation sign.

ISSN:1082-6076    

DOI:10.1080/10826079608001923

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A high performance liquid chromatographic assay with electrochemical detection has been developed for the determination of etoposide in human plasma samples. 2-acetamidophenol was used as internal standard and extraction was performed with ethyl ether-dichloromethane (2:1) in a single step. Analyses were carried out on a Nova Pak C8column using methanol-75 mM acetate buffer (45:55) as mobile phase. The effluent from the column was monitorized at +800 mV against Ag/AgCl and the resulting current was registered. The assay was linear within the range of 0.02-4 μg/mL, coefficients of variation being lower than 10%. Detection limit was 5 ng/mL. The method is rapid and economical. Therefore, it is suitable for routine monitoring of etoposide pharmacokinetics after administration of low oral doses according to recent therapeutic schemes.

ISSN:1082-6076    

DOI:10.1080/10826079608001924

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Serotonin (5-hydroxytryptamine; 5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) were determined simultaneously in rabbit platelet by a sensitive microbore high-performance liquid chromatographic method with electrochemical detection. The detection limit of 5-HT in rabbit platelet suspension was 0.1 ng/mL. To evaluate the 5 – HT release from platelet suspension, the aggregating agent arachidonic acid 30 and 100 μM were added and the 5-HT was elevated from basal level 2.96±0.89 ng/mL to 154.72±28.03 and 246.77±24.38 ng/mL, respectively. The results demonstrated that magnolol inhibits arachidonic acid-induced 5-HT release from platelet suspension significantly.

ISSN:1082-6076    

DOI:10.1080/10826079608001925

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

A precise and accurate HPLC method for the quantification of ketorolac in human plasma is described. Ketorolac and an added internal standard (a fluoro analog of ketorolac) are extracted from acidified plasma samples and the extract is further purified. The reconstituted sample is injected onto a reverse phase HPLC column. The method has a linear concentration range of 0.010-3.00 μg of ketorolac per aliquot of plasma, using 0.1 to 1.0 mL of plasma for analysis. The quantification limit of the method is 0.010 μg/mL. The intra- and inter-assay % CVs were less than 5.5%, and the mean recoveries ranged from 96% to 109%. The absolute recovery was 92%.

ISSN:1082-6076    

DOI:10.1080/10826079608001926

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor