References of "Chiap, Patrice"
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See detailLiquid chromatographic analysis of local anesthetics in human plasma after sample preparation by on-line dialysis. Optimization by use of experimental design
Chiap, Patrice ULg; Boulanger, Bruno ULg; Fotsing, Lucas ULg et al

in Chromatographia (2001), 53(11-12), 678-686

A fully automated method involving dialysis, clean-up and enrichment of the dialysate on a pre-column packed with a strong cation-exchange phase, and subsequent liquid chromatographic (LC) analysis with ... [more ▼]

A fully automated method involving dialysis, clean-up and enrichment of the dialysate on a pre-column packed with a strong cation-exchange phase, and subsequent liquid chromatographic (LC) analysis with UV detection at 220 nm has been developed for the determination of local anesthetics (prilocaine, mepivacaine, and bupivacaine) in human plasma. All sample-handling operations were executed automatically by means of an Asted XI system. To identify the most important conditions affecting analyte recovery from the dialysis and trace-enrichment processes, a seven-factor D-optimal design with 16 experimental points was elaborated as a screening test A four-factor D-optimal design with 24 experimental points was then used to predict and optimize analyte recovery. Derringer's desirability function was also used to deduce optimum conditions for analyte recovery and dialysis time within the experimental domain. Finally, the method developed was validated. Mean recoveries were approximately 72% for bupivacaine and approximately 67% for mepivacaine and prilocaine. The limits of quantification were 28 ng mL(-1) for bupivacaine and 25 ng mL(-1) for mepivacaine and prilocaine. [less ▲]

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See detailDetermination of Albendazole and Its Main Metabolites in Ovine Plasma by Liquid Chromatography with Dialysis as an Integrated Sample Preparation Technique
Chiap, Patrice ULg; Evrard, Brigitte ULg; Bimazubute, M. A. et al

in Journal of Chromatography. A (2000), 870(1-2), 121-34

Albendazole is a benzimidazole derivative with a broad-spectrum activity against human and animal helminth parasites. In order to determine the main pharmacokinetic parameters in sheep after oral and ... [more ▼]

Albendazole is a benzimidazole derivative with a broad-spectrum activity against human and animal helminth parasites. In order to determine the main pharmacokinetic parameters in sheep after oral and intravenous administration of a new formulation of albendazole (an aqueous solution), a fully automated method was developed for the determination of this drug and its main metabolites, albendazole sulfoxide (active metabolite) and sulfone in ovine plasma. This method involves dialysis as purification step, followed by enrichment of the dialysate on a precolumn and liquid chromatography (LC). All sample handling operations were executed automatically by means of an ASTED XL system. After conditioning of the trace enrichment column (TEC) packed with octadecyl silica with pH 6.0 phosphate buffer containing sodium azide, the plasma sample, in which a protein releasing reagent (1 M HCl) containing Triton X-100 was automatically added, was loaded in the donor channel and dialysed on a cellulose acetate membrane in the static-pulsed mode. The dialysis liquid consisted of pH 2.5 phosphate buffer. By rotation of a switching valve, the analytes were eluted from the TEC in the back-flush mode by the LC mobile phase and transferred to the analytical column, packed with octyl silica. The chromatographic separation was performed at 35 degrees C and the analytes were monitored photometrically at 295 nm. Due to the differences in hydrophobic character between albendazole and its metabolites, a gradient elution was applied. The mobile phase consisted of a mixture of acetonitrile and pH 6.0 phosphate buffer. The proportion of organic modifier was increased from 10.0 to 50.1% in 12.30 min, then from 50.1 to 66.9% in 1.70 min. First, the gradient conditions and the temperature were optimised for the LC separation using the DryLab software. Then, the influence of some parameters of the dialysis process on analyte recovery was investigated. Finally, the method developed was validated. The mean recoveries for albendazole and its metabolites were about 70 and 65%, respectively. The limits of quantification for albendazole and its metabolites were 10 and 7.5 ng/ml, respectively. [less ▲]

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See detailAutomated Liquid Chromatographic Determination of Atenolol in Plasma Using Dialysis and Trace Enrichment on a Cation-Exchange Precolumn for Sample Handling
Chiap, Patrice ULg; Buraglia, B. M.; Ceccato, Attilio ULg et al

in Journal of Chromatography. B : Biomedical Sciences and Applications (2000), 739(1), 205-17

A fully automated method involving dialysis combined with trace enrichment was developed for the liquid chromatographic (LC) determination of atenolol, a hydrophilic beta-blocking agent, in human plasma ... [more ▼]

A fully automated method involving dialysis combined with trace enrichment was developed for the liquid chromatographic (LC) determination of atenolol, a hydrophilic beta-blocking agent, in human plasma. The plasma samples were dialysed on a cellulose acetate membrane and the dialysate was reconcentrated on a short trace enrichment column (TEC) packed with a strong cation-exchange material. All sample handling operations can be executed automatically by a sample processor (ASTED system). After TEC conditioning, the plasma sample, to which the internal standard (sotalol, another hydrophilic beta-blocker) was automatically added, was introduced in the donor channel and dialysed in the static/pulsed mode. The dialysis liquid consisted of 4.3 mM phosphoric acid. When the dialysis process was discontinued, the analytes were eluted from the TEC in the back-flush mode by the LC mobile phase and transferred to the analytical column, packed with octyl silica. The LC mobile phase consisted of phosphate buffer, pH 7.0-methanol (81:19; v/v) with 1-octanesulfonate. Atenolol and the internal standard were monitored photometrically at 225 nm. The different parameters influencing the dialysis and trace enrichment processes were optimised with respect to analyte recovery. The influence of two different kinds of cation-exchange material on analyte recovery and peak efficiency was also studied. The method was then validated in the concentration range 25-1000 ng/ml. The mean recovery for atenolol was 65% and the limit of quantitation was 25 ng/ml. [less ▲]

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See detailObjectives of pre-study validation and decision rules
Boulanger, Bruno ULg; Dewé, Walthère ULg; Chiap, Patrice ULg et al

Conference (2000)

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See detailMultivariate optimization approach for the separation of water-soluble vitamins and related compounds by capillary electrophoresis.
Fotsing, Lucas; Boulanger, Bruno ULg; Chiap, Patrice ULg et al

in Biomedical Chromatography : BMC (2000), 14(1), 10-1

Multivariate optimization approach for the separation of water-soluble vitamins and related compounds by capillary electrophoresis.

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See detailNew strategy for the validation of chromatographic bioanalytical methods
Chapuzet, E.; Mercier, N.; Bervoas-Martin, S. et al

in STP Pharma Pratiques (2000), 10(1), 21-38

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See detailExample of application of the new strategy proposed for the validation of chromatographic bioanalytical methods
Chapuzet, E.; Mercier, N.; Bervoas-Martin, S. et al

in STP Pharma Pratiques (2000), 10(2), 79-101

Detailed reference viewed: 86 (9 ULg)