1
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Smet E, Staelens L, Vander Heyden Y, Baeyens WR, Aboul-Enein HY, van der Weken G, García-Campaña AM. Optimization of the chiral separation of some 2-arylpropionic acids on an avidin column by modeling a combined response. Chirality 2002; 13:556-67. [PMID: 11579449 DOI: 10.1002/chir.1177] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The enantiomeric separation of some nonsteroidal antiinflammatory drugs was investigated on an avidin column. An experimental design approach (central composite design) was used to evaluate the effects of three method parameters (pH, concentration of organic modifier, and buffer concentration) on the analysis time and the resolution, as well as to model these responses. This revealed that the organic modifier concentration and sometimes the pH are significant parameters to control because of their influence on both analysis time and resolution. Furthermore, the central composite design results were combined in a multicriteria decision-making approach in order to obtain a set of optimal experimental conditions leading to the most desirable compromise between resolution and analysis time.
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Affiliation(s)
- E Smet
- Laboratory of Drug Quality Control, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
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2
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Smet E, Baeyens WR, Van der Weken G, Kiekens F, Vervaet C, Remon JP. A validated HPLC method for the determination of thiazinamium methylsulphate in pharmaceutical preparations. J Pharm Biomed Anal 2000; 23:175-83. [PMID: 10898168 DOI: 10.1016/s0731-7085(00)00267-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The phenothiazine derivative thiazinamium methylsulphate is a drug with antihistaminic and anticholinergic properties, often used in some types of obstructive lung diseases. Because there is a lack of chromatographic data available for its determination, the objective of the present investigation was to develop a sensitive and rapid HPLC method for the quantitative estimation of thiazinamium methylsulphate in a pharmaceutical dosage form, applicable to routine analysis. The drug was chromatographed on a C18-reversed phase system applying a Licrocart column (LiChrospher 100 RP 18, 125 x 4 mm) with a mobile phase consisting of acetonitrile-water (3:7, v/v), employing as ion-pairing agent octanesulphonic acid sodium salt (20 mM) together with N,N-dimethyloctylamine (20 mM), adjusted to pH 3. Detection occurred at 254 nm. Propylparaben was used as an internal standard. The method was applied to solutions for intramuscular injection containing thiazinamium methylsulphate (65 mg/2 ml). Since little sample preparation is required, most analyses can be carried out within 15 min. The optimized method was validated and provided acceptable results with respect to linearity (r = 0.9999), precision and accuracy in the concentration range of 26-78 microg/ml. The proposed method is presently employed to investigate the stability of thiazinamium methylsulphate in solutions for intramuscular injection in the presence of anti-oxidizing agents.
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Affiliation(s)
- E Smet
- Department of Pharmaceutical Analysis, Faculty of Pharmaceutical Sciences, University of Ghent, Belgium.
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3
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Abstract
The determination of the alkaloids reserpine, rescinnamine and yohimbine based on a chemiluminogenic reaction with potassium permanganate in the presence of polyphosphoric acid is described. The investigation was carried out using a batch and a flow injection chemiluminometer. Both approaches were accurate and precise, allowing the measurement of reserpine within the ranges 0.100-3.00 and 0.050-3.00 micrograms ml-1 with RSD values for 1.00 microgram ml-1 of 1.91 and 0.33% (n = 8) with the batch and the flow injection manifold, respectively. The procedure was successfully applied to formulations after extraction of reserpine with chloroform, with recoveries from commercial formulations within the range 95.2-99.0%.
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Affiliation(s)
- N Pinotsis
- Department of Chemistry, University of Athens, Greece
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4
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Abstract
Several chemiluminescence-based reactions are applicable to the determination of various bio-pharmaceutically important analytes, and they can be applied for monitoring chemiluminescence emission using flow injection, liquid chromatographic and capillary electrophoretic analysis, as well as for the development of chemiluminescence-based sensors or in immunoassays. As in general the emission intensity is linearly proportional to the concentration of any of the reagents, the technique allows the analysis of different species involved in the light-producing reaction, amongst which are the chemiluminescent reagent, oxidants, inhibitors, cofactors, catalysts, some fluorophore, etc. The present overview illustrates some important applications of the last decade on this rather unfamiliar luminescence technique to detectional challenges in the liquid phase. The required instrumentation is limited as no external light source is needed. Also, the technique opens perspectives for increasing detection sensitivity in miniaturized flowing streams. On the other hand, several drawbacks still limit full application, eg dependence of the emission signal upon a number of environmental factors forcing the analyst to make a compromise between separating and measuring conditions, a lack of selectivity in specific cases, the critical detection of the signal at strictly defined periods, especially in the case of sharp emission vs time profiles, and the development of detection devices in capillary electrophoresis.
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Affiliation(s)
- A M García-Campaña
- University of Granada, Faculty of Sciences, Department of Analytical Chemistry, Spain
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5
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Baeyens WR, Van der Weken G, Haustraete J, Aboul-Enein HY, Corveleyn S, Remon JP, García-Campaña AM, Deprez P. Application of the restricted-access precolumn packing material alkyl-diol silica in a column-switching system for the determination of ketoprofen enantiomers in horse plasma. J Chromatogr A 2000; 871:153-61. [PMID: 10735295 DOI: 10.1016/s0021-9673(99)01089-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The group of LiChrospher ADS (alkyl-diol silica) sorbents that make part of a unique family of restricted-access materials, have been developed as special packings for precolumns used in the LC-integrated sample processing of biofluids. The advantage of these sorbents lies in the direct injection of untreated biological fluids, that is without sample clean-up, the elimination of the protein matrix with a quantitative recovery together with an on-column enrichment. The present method is based on previous work applying UV detection at 260 nm for ketoprofen determinations. Plasma samples introduced to the ADS precolumn using a 0.1 M phosphate buffer, pH 7.0. After washing with the buffer the ADS column was backflushed with the mobile phase 0.01 M phosphate buffer-6% (v/v) 2-propanol-5 mM octanoic acid at a pH of 5.5, thus transporting the analytes to the chiral-HSA (human serum albumin) (100x4.0 mm) column where the separation of the ketoprofen enantiomers was achieved with a resolution factor of 1.4. The developed column-switching method was fully applicable to plasma injections.
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Affiliation(s)
- W R Baeyens
- Laboratory of Drug Quality Control, Faculty of Pharmaceutical Sciences, University of Ghent, Belgium.
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6
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Affiliation(s)
- W R Baeyens
- University of Ghent, Faculty of Pharmaceutical Sciences, Department of Pharmaceutical Analysis, Laboratory of Drug Quality Control, Harelbekestraat 72, B-9000 Ghent, Belgium
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7
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Baeyens WR, Van der Weken G, Aboul-Enein HY, Reygaerts S, Smet E. Comparison of the enantiomeric separation of some 2-arylpropionic acids on a novel Pirkle-concept stationary packing by narrow-bore and conventional liquid chromatography. Biomed Chromatogr 2000; 14:58-60. [PMID: 10664568 DOI: 10.1002/(sici)1099-0801(200002)14:1<58::aid-bmc978>3.0.co;2-b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- W R Baeyens
- Laboratory of Drug Quality Control, Faculty of Pharmaceutical Sciences, University of Ghent, Harelbekestraat 72, B-9000 Ghent, Belgium
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8
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Baeyens WR, Van der Weken G, Haustraete J, Aboul-Enein HY, Corveleyn S, Remon JP, García-Campaña AM, Deprez P. Direct HPLC analysis of ketoprofen in horse plasma applying an ADS-restricted access-phase. Biomed Chromatogr 1999; 13:450-4. [PMID: 10534755 DOI: 10.1002/(sici)1099-0801(199911)13:7<450::aid-bmc910>3.0.co;2-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Making up part of the unique family of restricted access materials (RAM) the Lichrospher ADS (alkyl-diol silica) sorbents have been developed as special packing materials for precolumns used for LC-integrated sample processing of biofluids. The advantage of such phases consists of direct injection of untreated biological fluids without sample clean-up and elimination of the protein matrix together with an on-column enrichment. The plasma samples, with internal standard phenacetin added (not essential), were brought onto the precolumn (C-18 ADS, 25 micron, 25 x 4 mm i.d.) using a phosphate buffer, 0.1 M, pH 7.0. After washing with the buffer, the ADS column was backflushed with the mobile phase phosphate buffer 0. 05 M pH 7.0: acetonitrile (80:20), thus transporting the analytes onto a reversed-phase column Ecocart 125-3 HPLC cartridge with a LiChrocart 4-4 guard column, both packed with LiChrospher 5 micron 100 RP-18; after separation detection was performed in UV at 260 nm. Essential features of the method include the novel precolumn packing, the absence of sample pretreatment, a quantitave recovery, good precision and accuracy, as well as a considerable reduction of analysis time compared to conventional manual methods applied in bioavailability studies.
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Affiliation(s)
- W R Baeyens
- Laboratory of Drug Quality Control, Faculty of Pharmaceutical Sciences, University of Ghent, Harelbekestraat 72, B-9000 Ghent, Belgium
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9
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Nakashima K, Kinoshita S, Wada M, Kuroda N, Baeyens WR. HPLC with fluorescence detection of urinary phenol, cresols and xylenols using 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride as a fluorescence labeling reagent. Analyst 1998; 123:2281-4. [PMID: 10396803 DOI: 10.1039/a804582h] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A simple and sensitive HPLC method for the determination of phenolic compounds, i.e., phenol (Phe), cresols (Cres) and xylenols (Xyls), was developed. After a pre-column fluorescence derivatization of these compounds with 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride (DIB-Cl) at 60 degrees C for 30 min, 11 DIB derivatives were successfully separated within 50 min with an ODS column using CH3CN-H2O-CH3OH (25 + 22 + 53, v/v) as the eluent. The detection limits of DIB derivatives at a signal-to-noise ratio of 3 ranged from 0.15 to 1.09 microM (0.2-1.6 pmol per 20 microliters). The precision of the proposed method for both within- and between-day assays of free and total phenol related compounds was satisfactory (RSD < 9.5%). By the proposed method, Phe and p-Cre could be detected in normal urine samples, and the calculated concentrations of free Phe and p-Cre in unhydrolysed urine samples were 1.5 +/- 1.3 and 23.9 +/- 24.3 microM and those of total Phe and p-Cre in hydrolysed urine samples were 87.3 +/- 81.2 and 200.7 +/- 195.4 microM (n = 21), respectively.
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Affiliation(s)
- K Nakashima
- School of Pharmaceutical Sciences, Nagasaki University, Japan
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10
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Baeyens WR, Schulman SG, Calokerinos AC, Zhao Y, García Campaña AM, Nakashima K, De Keukeleire D. Chemiluminescence-based detection: principles and analytical applications in flowing streams and in immunoassays. J Pharm Biomed Anal 1998; 17:941-53. [PMID: 9884186 DOI: 10.1016/s0731-7085(98)00062-4] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The present paper provides the principles of chemiluminescence (CL) and its powerful applications in analytical chemistry, mainly in the area of flow injection analysis, column liquid chromatographic and capillary electrophoretic separating systems, and its potential in immunoassays. CL is light produced by a chemical reaction. The most common advantages of chemiluminescent reactions are the relatively simple instrumentation required, the very low detection limits and wide dynamic ranges, which have contributed to the interest of CL detection in flow injection analysis, high performance liquid chromatography, including miniaturized systems, and, most recently, the exploding area of capillary electrophoresis. The latter powerful microanalytical separation technique offers high numbers of theoretical plates and relatively short analysis times requiring only small sample volumes, the migrating system comprising aqueous buffer solutions. In non-isotopic immunoassays, covering a great variety of applications in human and veterinary medicine, forensic medicine, agriculture and food industry, the radioisotope is replaced by a fluorescence or chemiluminescent label. The use of CL as a detection principle permits quantitative determination of various compounds at low concentrations. Disadvantages of the CL-based technique may include lack of sufficient selectivity and sensitivity to various physicochemical factors.
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Affiliation(s)
- W R Baeyens
- University of Ghent, Faculty of Pharmaceutical Sciences, Department of Pharmaceutical Analysis, Belgium.
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11
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Pérez-Ruiz R, Martínez-Lozano C, Baeyens WR, Sanz A, San-Miguel MT. Determination of tiopronin in pharmaceuticals using a chemiluminescent flow-injection method. J Pharm Biomed Anal 1998; 17:823-8. [PMID: 9682167 DOI: 10.1016/s0731-7085(98)00013-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A flow-injection method for the determination of tiopronin in the range 1 x 10(-7)-7 x 10(-5) M is described. The procedure is based on the chemiluminescent reaction of tiopronin with cerium(i.v.) in sulphuric acid medium using rhodamine 6G and quinine as fluorophors. The flow-injection method is rapid and precise and allows measurements of up to 80 solutions per hour. The applicability of the method to the determination of tiopronin in pharmaceutical preparations was demonstrated by investigating the effect of potential interferences and by analysing commercial preparations.
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Affiliation(s)
- R Pérez-Ruiz
- Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, Spain
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12
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Affiliation(s)
- H Rong
- Laboratory of Pharmacognosy and Phytochemistry, University of Gent, Faculty of Pharmaceutical Sciences, Belgium
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13
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Abstract
Two methodologies have been proposed for a simple statistical estimation of the detection limits in microbore-HPLC and CE techniques. Due to the impossibility to measure the blank, by using the extrapolated or approximated expressions it is possible to obtain a straightforward approach of the detection limits from the study of the residuals of the calibration data set, avoiding tedious treatment of the signals. The utility of these expressions has been checked on the data from an experimental microbore HPLC system.
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Affiliation(s)
- A M García Campaña
- Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Spain
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14
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Baeyens WR, Van der Weken G, Van Overbeke A, Corveleyn S, Remon JP, Deprez P. Comparative narrow-bore high-performance liquid chromatographic determination of ketoprofen in horse plasma. Biomed Chromatogr 1998; 12:167-9. [PMID: 9646927 DOI: 10.1002/(sici)1099-0801(199805/06)12:3<167::aid-bmc798>3.0.co;2-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- W R Baeyens
- Laboratory of Drug Quality Control, University of Ghent, Faculty of Pharmaceutical Sciences, Belgium
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15
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Baeyens WR, Van der Weken G, Van Overbeke A, De Meyer S, García Campaña AM, Kiekens P, Remon JP, Dewaele C. Narrow-bore reversed-phase liquid chromatography of metronidazole benzoate and its hydrolysis products. Biomed Chromatogr 1998; 12:164-6. [PMID: 9646926 DOI: 10.1002/(sici)1099-0801(199805/06)12:3<164::aid-bmc797>3.0.co;2-h] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- W R Baeyens
- Department of Pharmaceutical Analysis, Faculty of Pharmaceutical Sciences, University of Ghent, Belgium
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16
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Ouyang J, Baeyens WR, Delanghe J, Van der Weken G, De Keukeleire D, Van Daele W, García Campaña AM, Calokerinos AC. Narrow-bore liquid chromatography coupled to chemiluminescence detection for the analysis of pharmaceutical preparations containing hydrochlorothiazide and captopril. Biomed Chromatogr 1998; 12:160-1. [PMID: 9646924 DOI: 10.1002/(sici)1099-0801(199805/06)12:3<160::aid-bmc795>3.0.co;2-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- J Ouyang
- University of Ghent, Faculty of Pharmaceutical Sciences, Department of Pharmaceutical Analysis, Belgium
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17
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Ouyang J, Baeyens WR, Delanghe J, Van der Weken G, De Keukeleire D, Calokerinos AC. Flow-injection analysis of hydrochlorothiazide applying sensitised chemiluminescence detection: optimisation in view of narrow-bore HPLC. Biomed Chromatogr 1998; 12:162-3. [PMID: 9646925 DOI: 10.1002/(sici)1099-0801(199805/06)12:3<162::aid-bmc796>3.0.co;2-q] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- J Ouyang
- University of Ghent, Faculty of Pharmaceutical Sciences, Department of Pharmaceutical Analysis, Belgium
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18
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Affiliation(s)
- A M García Campaña
- University of Granada, Faculty of Sciences, Dept. of Analytical Chemistry, Spain
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19
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Zhao Y, Baeyens WR, Zhang X, Calokerinos AC, Nakashima K, Van der Weken G. Chemiluminescence determination of tiopronin by flow injection analysis based on cerium (IV) oxidation sensitized by quinine. Biomed Chromatogr 1997; 11:117-8. [PMID: 9137780 DOI: 10.1002/(sici)1099-0801(199703)11:2<117::aid-bmc669>3.0.co;2-v] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Y Zhao
- University of Ghent, Faculty of Pharmaceutical Sciences, Department of Pharmaceutical Analysis, Belgium
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20
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Affiliation(s)
- Z D Zhang
- University of Ghent, Faculty of Pharmaceutical Sciences, Department of Pharmaceutical Analysis, Belgium
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21
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Pecanac D, Baeyens WR, Imai K, Van Overbeke A, Van der Weken G, De Waele C. Enantiomeric separation of some 2-arylpropionic acids with a chiral fluorescence labelling reagent by narrow-bore liquid chromatography. Biomed Chromatogr 1997; 11:83-4. [PMID: 9137764 DOI: 10.1002/(sici)1099-0801(199703)11:2<83::aid-bmc646>3.0.co;2-l] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- D Pecanac
- Department of Pharmaceutical Chemistry and Drug Analysis, Faculty of Pharmacy, University of Belgrade, Yugoslavia
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22
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Baeyens WR, Van der Weken G, Van de Voorde I, Dewaele C. Micro-bore LC of nonapeptides and some primary amine drugs on a polymer column applying postcolumn fluorescamine labelling. Biomed Chromatogr 1997; 11:111-2. [PMID: 9137777 DOI: 10.1002/(sici)1099-0801(199703)11:2<111::aid-bmc666>3.0.co;2-l] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- W R Baeyens
- Dept. of Pharmaceutical Analysis, Faculty of Pharmaceutical Sciences, University of Ghent, Belgium
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23
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Zhao Y, Baeyens WR, Zhang X, Nakashima K, Calokerinos AC, Van der Weken G. Chemiluminescent determination of tiopronin and its metabolite, 2-mercaptopropionic acid, in urine by HPLC coupled with a flow injection set-up. Biomed Chromatogr 1997; 11:115-6. [PMID: 9137779 DOI: 10.1002/(sici)1099-0801(199703)11:2<115::aid-bmc668>3.0.co;2-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Y Zhao
- University of Ghent, Faculty of Pharmaceutical Sciences, Laboratory of Drug Quality, Belgium
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24
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Baeyens WR, Van der Weken G, Vanden Bossche Y, van Overbeke A, Imal K. Flow injection analysis of some nonapeptides derivatized with 4-fluoro-7-nitrobenzo-2,1,3-oxadiazole. Biomed Chromatogr 1997; 11:109-10. [PMID: 9137776 DOI: 10.1002/(sici)1099-0801(199703)11:2<109::aid-bmc665>3.0.co;2-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- W R Baeyens
- Department of Pharmaceutical Analysis, Faculty of Pharmaceutical Sciences, University of Ghent, Belgium
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25
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Affiliation(s)
- L P Palilis
- University of Athens, Laboratory of Analytical Chemistry, Greece
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26
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Zhao Y, Baeyens WR, Zhang X, Calokerinos AC, Nakashima K, Van der Weken G. Chemiluminescence determination of tiopronin by flow injection analysis based on cerium(IV) oxidation sensitized by quinine. Analyst 1997; 122:103-6. [PMID: 9124691 DOI: 10.1039/a605703i] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A flow injection analysis method is proposed for the determination of tiopronin based upon the oxidation by cerium(IV) in dilute sulfuric acid medium and sensitized by quinine. With the peak height as a quantitative parameter applying optimum working conditions, tiopronin is determined over the 1-400 microM range (150 microliters per injection, n = 10, r = 0.9994) with a detection limit of 0.34 microM and an RSD (n = 10) less than 2% at 20 and 50 microM. The proposed method, combining the advantages of speed and sensitivity, was applied to the routine determination of tiopronin in a pharmaceutical preparation.
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Affiliation(s)
- Y Zhao
- Laboratory of Drug Quality Control, Faculty of Pharmaceutical Sciences, University of Ghent, Belgium
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27
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Schulman SG, Kelly RN, Miyawa JH, Baeyens WR. Invariance of activity coefficients for the hydrogen ion with charge-type of fluorescent indicators in aqueous-methanol solutions. J Fluoresc 1996; 6:195-8. [PMID: 24227342 DOI: 10.1007/bf00732822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/1996] [Accepted: 09/05/1996] [Indexed: 10/26/2022]
Abstract
Steady-state fluorimetric pH titrations of three fluorescent indicators of differing charge-type were carried out in aqueous methanol solutions containing up to 64 mol% methanol. The plot of the ratio of the relative fluorescence efficiency of the indicator acid to that of its conjugate base versus the product of the formal hydrogen ion concentration and the appropriate Bronsted kinetic activity factor gives straight lines for titrations in each mixed solvent, just as it does in water, but only if the constant terms in the Bronsted factor are modified to account for the bulk dielectric constant in each solvent. The product of the formal charges on the proton and the particular conjugate base studied in each titration must also be included in the Bronsted factor. This supports the hypothesis that a valid operational pH can be defined and kinetic parameters related to proton transfer can be extracted from the fluorimetric titrations in mixed solvents.
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Affiliation(s)
- S G Schulman
- College of Pharmacy, University of Florida, 32610-0485, Gainesville, Florida
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28
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Zhang ZD, Baeyens WR, Zhang XR, Van der Weken G. Chemiluminescence flow-injection analysis of captopril applying a sensitized rhodamine 6G method. J Pharm Biomed Anal 1996; 14:939-45. [PMID: 8817998 DOI: 10.1016/s0731-7085(95)01733-x] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A flow-injection analysis with chemiluminescence detection is described for the determination of captopril based on the photochemical reaction with cerium(IV) in sulphuric acid medium yielding a strong chemiluminescent signal which can be sensitized by some fluorescers. The proposed procedure has a linear application range of 1 x 10(-6) - 2 x 10(-4) M (r = 0.997) with a detection limit of 2 x 10(-7) M, an RSD of 2.8% at 1 x 10(-6) M captopril, and a sample measurement frequency of 500 h-1. The method was used for the simple and rapid determination of captopril in a pharmaceutical preparation.
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Affiliation(s)
- Z D Zhang
- Department of Pharmaceutical Analysis, Faculty of Pharmaceutical Sciences, University of Ghent, Belgium
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Abstract
The phenomenon of chemiluminescence allows the development of simple analytical procedures using low cost instrumentation which can be easily controlled by computers. The sensitivity of the methods is excellent, and selectivity is improved by high-performance liquid chromatographic separation. A broad area of chemiluminometric applications is drug analysis, which is reviewed in this paper.
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Affiliation(s)
- A C Calokerinos
- Laboratory of Analytical Chemistry, University of Athens, Greece
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Xinrong Z, Baeyens WR, Van der Weken G, Calokerinos AC, Nakashima K. Chemiluminescence analysis of captopril: comparison between luminol and rhodamine B-sensitized cerium(IV) methods. J Pharm Biomed Anal 1995; 13:425-9. [PMID: 9696552 DOI: 10.1016/0731-7085(95)01294-u] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Two chemiluminescence methods for the determination of captopril are compared in the present paper. The first method is based on the reaction of captopril with the luminol-hydrogen peroxide-copper(II) system, the copper(II) ion acting as a key species in the light-emitting process. The catalytic activity of copper(II) decreases due to complex formation with the sulphhydrylic captopril analyte. Application of this indirect method allows captopril determinations in the 8.0-1.0 microM range as starting concentrations. Similarly, captopril was capable of generating chemiluminescence from acid cerium(IV) solutions, a reaction that could be analytically exploited by the inclusion of the rhodamine B fluorophore yielding a sensitized-type of chemiluminescence emission that allowed quantitation of captopril concentrations in the 0.1-6.0 microM range with a detection limit of 0.037 microM (original concentration). For both types of reaction the experimental conditions were optimized and a direct application was carried out on a commercial drug formulation.
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Affiliation(s)
- Z Xinrong
- University of Ghent, Faculty of Pharmaceutical Sciences, Department of Pharmaceutical Analysis, Belgium
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Ling BL, Baeyens WR, Dewaele C, Del Castillo B. Packed capillary liquid chromatography coupled to fluorescence detection: application to human blood samples for the determination of glutathione. J Pharm Biomed Anal 1992; 10:985-8. [PMID: 1298406 DOI: 10.1016/0731-7085(91)80108-l] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The present investigation analyses the potentials of capillary chromatography using packed fused silica capillaries filled with 5 microns RP-18 for the fluorescence determination of glutathione in human blood samples. Adaptation of conventional HPLC equipment for miniaturized chromatographic assays proved successful. Sample preparation was relatively simple, though care should be taken in sample handling. The thiolic compound mercaptoethanol was used as internal standard. Qualitative determinations were based on standard addition providing increased peak heights at identical retention times. Quantitative determinations gave linear calibration curves, with a standard glutathione recovery of 98.9% and an intra-assay reproducibility of 3.3%. The glutathione values measured appeared within the normal range of 0.9-1.7 mmol glutathione per litre of blood.
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Affiliation(s)
- B L Ling
- Dept of Bromatology and Pharmaceutical Analytical Techniques, Faculty of Pharmacy, Complutense University of Madrid, Spain
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Lin Ling B, Baeyens WR, Van Acker P, Dewaele C. Determination of ascorbic acid and isoascorbic acid by capillary zone electrophoresis: application to fruit juices and to a pharmaceutical formulation. J Pharm Biomed Anal 1992; 10:717-21. [PMID: 1298373 DOI: 10.1016/0731-7085(91)80070-p] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Capillary zone electrophoresis was applied to the determination of ascorbic and isoascorbic acid, analysing the various parameters of influence such as the separation voltage, the buffer pH and concentration, the type of separation capillary or the loading conditions. Both analytes could be adequately determined within 5 min. The proposed method uses a 20 cm x 25 microns i.d. coated column, 0.1 M phosphate buffer pH 5.0, 8 kV separation voltage and light absorption detection at 265 nm. Linear calibration curves were obtained in the 0-1 mg mi-1 range, with detection limits of 0.5 micrograms ml-1. This method proved to be very rapid, simple and practical for the qualitative and quantitative determination of ascorbic acid in lemon and orange juices, as well as in a commercially available pharmaceutical formulation.
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Affiliation(s)
- B Lin Ling
- Department of Bromatology and Pharmaceutical Analytical Techniques, Faculty of Pharmacy, Complutense University of Madrid, Spain
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Abstract
Different thiol compounds of biological and pharmacological interest were separated on a packed reversed-phase fused-silica capillary column and determined with fluorescence detection. Conventional inexpensive liquid chromatographic equipment could be adapted for such purposes, providing a highly efficient analytical system. The different compounds were derivatized with the fluorogenic reagents SBD-F and ABD-F and chromatographed both isocratically and in the gradient mode in order to separate a series of thiols with widely varying polarities. Subsequently the derivatives were measured at lambda ex. = 380 nm and lambda em. = 510 nm. Application of the system to biological and pharmacological samples is suggested.
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Affiliation(s)
- B L Ling
- Department of Pharmaceutical Chemistry and Drug Quality Control, State University of Ghent, Belgium
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Baeyens WR, Ling BL, Brinkman UA, Schulman SG. Principles and applications of luminescence spectrometry coupled to liquid chromatographic techniques. J Biolumin Chemilumin 1989; 4:484-99. [PMID: 2678924 DOI: 10.1002/bio.1170040164] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
An overview is presented of the physicochemical basis of luminescence, and its application to the detection of chemicals (drugs, biomedically important compounds, environmentally active substances) in liquid chromatographic systems.
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Affiliation(s)
- W R Baeyens
- State University of Ghent, Faculty of Pharmaceutical Sciences, Ghent, Belgium
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Abstract
Luminescence emission from drugs is strongly dependent on their physicochemical environment. Several biomedically and environmentally important compounds and pharmaceuticals exhibit sufficient intrinsic luminescence properties to allow their determination by high-performance liquid chromatography (HPLC) with fluorimetric, chemiluminescence or room temperature phosphorimetric detection. In the case of weakly fluorescing compounds it is possible to use the dependence of the emitted radiation on the molecular environment at the moment of measurement. The composition of the eluent, i.e. solvents, added salts and buffers, pH and ionic strength, oxygen content and temperature, are of the highest importance for the luminescence detection of drugs in solution (e.g. in liquid chromatography) or adsorbed onto solid surfaces (e.g. in thin-layer chromatography). Post-column or post-plate acid-base manipulation and the use of specific reagents may remarkably enhance the observed luminescence of several molecules. The term "enhancement" of luminescence comprises various sample treatments leading to an increase of the emitted radiation. These treatments include the addition of non-fluorescent compounds to, or the creation of organized media (surfactants, cyclodextrins, heavy atoms) in, the sample to be measured. They may also involve changes in molecular environment, pH, the application of excessive drying conditions, the removal of oxygen, the protection of adsorbed compounds against non-radiative decay mechanisms by means of specific spraying or dipping conditions, amongst others. The use of organized media in luminescence spectroscopy is growing. Many of the recent studies have involved micelles for enhancing the fluorescence, room temperature phosphorescence and chemiluminescence of several chemicals. Cyclodextrins are increasingly used for various analytical applications. Liquid paraffin, triethanolamine, dodecane, Triton X-100 and Fomblin Y-Vac are commonly used fluorescence enhancers in chromatographic assays. Examples of these systems in drug analysis are presented.
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Affiliation(s)
- W R Baeyens
- Laboratory of Pharmaceutical Chemistry and Drug Analysis, Faculty of Pharmaceutical Sciences, State University of Ghent, Belgium
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Abstract
Several thiols of biological and pharmacological interest, including glutathione, coenzyme A, acetylcysteine and captopril were derivatized with the fluorogenic reagents SBD-F and ABD-F and analysed by high-performance thin-layer chromatography (HPTLC)-fluorodensitometry on silica gel 60 plates, using isopropyl ether-methanol-water-acetic acid (9:8:2:1, v/v/v/v) as the developing solvent. The luminescence was considerably increased when several types of enhancers were applied as dipping reagents: Triton X-100, liquid paraffin and cyclodextrins; thus the detectability of the thiol fluorophores was improved. The influence of enhancer concentration, method of application, sample concentration, drying conditions and measuring time after plate dipping were investigated. The greatest enhancement was achieved using a 40% (v/v) solution of Triton X-100 in toluene as a dipping reagent for the determination of SBD-acetylcysteine; more than a 10-fold increase of the fluorescence signal was obtained, allowing low picogram detection limits.
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Affiliation(s)
- B L Ling
- Laboratory of Pharmaceutical Chemistry and Drug Analysis, Faculty of Pharmaceutical Sciences, State University of Ghent, Belgium
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Ling BL, Baeyens WR, Del Castillo B, Imai K, De Moerloose P, Stragier K. Determination of thiols of biological and pharmacological interest by high-performance thin-layer chromatography and fluorescence scanning densitometry. J Pharm Biomed Anal 1989; 7:1663-70. [PMID: 2490555 DOI: 10.1016/0731-7085(89)80180-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The application of high-performance thin-layer chromatography (HPTLC) with fluorescence scanning densitometry provides a simple, rapid and reliable system for the qualitative and quantitative determination of several thiols of biological and pharmacological interest. The determination of a mixture of thiols (captopril, coenzyme A, cysteamine, cysteine and glutathione), together with their disulphides may readily be performed by pre-chromatographic derivatization with the thiol-specific fluorobenzoxadiazole reagents SBD-F and ABD-F, followed by HPTLC separation on silica gel plates using isopropyl ether-methanol-water-acetic acid (9:8:2:1, v/v/v/v) as the developing solvent, and fluorodensitometric measurement of the fluorescing derivatives. Detection limits of about 30 pg (coenzyme A) to 6 pg (cysteamine) per spot were achieved; the relative standard deviation (RSD) of the complete procedure was 1.16-3.2%.
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Affiliation(s)
- B L Ling
- Laboratory of Pharmaceutical Chemistry and Drug Analysis, Faculty of Pharmaceutical Sciences, State University of Ghent, Belgium
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Affiliation(s)
- W R Baeyens
- State University of Ghent, Faculty of Pharmaceutical Sciences, Belgium
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