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Crapnell R, Banks CE. Electroanalytical Overview: The Determination of Levodopa (L-DOPA). ACS MEASUREMENT SCIENCE AU 2023; 3:84-97. [PMID: 37090256 PMCID: PMC10120037 DOI: 10.1021/acsmeasuresciau.2c00071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/21/2023] [Accepted: 01/25/2023] [Indexed: 05/03/2023]
Abstract
L-DOPA (levodopa) is a therapeutic agent which is the most effective medication for treating Parkinson's disease, but it needs dose optimization, and therefore its analytical determination is required. Laboratory analytical instruments can be routinely used to measure L-DOPA but are not always available in clinical settings and traditional research laboratories, and they also have slow result delivery times and high costs. The use of electroanalytical sensing overcomes these problems providing a highly sensitivity, low-cost, and readily portable solution. Consequently, we overview the electroanalytical determination of L-DOPA reported throughout the literature summarizing the endeavors toward sensing L-DOPA, and we offer insights into future research opportunities.
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Determination of levodopa by chromatography-based methods in biological samples: a review. ANAL SCI 2022; 38:1009-1017. [PMID: 35715690 DOI: 10.1007/s44211-022-00132-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 05/12/2022] [Indexed: 11/01/2022]
Abstract
Levodopa (L-DOPA) is the most effective drug for Parkinson's disease; however, various side effects occur during therapy. L-DOPA metabolites and the high cumulative dose of L-DOPA were responsible for its side effects. It is necessary to monitor the concentration of L-DOPA and its metabolites for individualized therapy. This review focuses on L-DOPA analysis by chromatography-based methods in biological matrices. Literature published up to September 2021 was collected in the PubMed, Web of Science, and Embase by using search strategy ("levodopa" OR "L-DOPA") AND ("chromatography"). A total of 1249 articles were identified and 32 articles were included. The contents for method development and validation were summarized and analyzed. Due to the instability of catecholamines (L-DOPA, dopamine, and 3-O-methyldopa) and carbidopa, antioxidation (0.5 mg sodium metabisulfite for 100 μL sample) and environment temperature control were used alone or in combination to enhance stability. Sample was mainly pretreated by protein precipitation (0.4-0.7 M perchloric acid). Separation was usually achieved using methanol or acetonitrile:water (with formic acid) on C18 columns. Mass spectrometry, electrochemical detector, ultraviolet-visible detector and fluorescence detector were used for detection. For L-DOPA, the calibration range was 2.5-10,000 ng/mL, the matrix effect and its coefficient of variation was 85-115 and -9.0-8.5%, and the recovery was 66.8-127.0%. Without stabilization strategy, L-DOPA was stable in plasma at room temperature for 1-7 h (4-6 h for most studies), at - 70 °C to - 80 °C for 10-20 days and after 3-5 freeze-thaw cycles. With stabilization strategies, the stability of L-DOPA in plasma was significantly improved. Metabolites of L-DOPA and enzyme inhibitors (carbidopa, entacapone, tolcapone and benserazide) were all stable in biological matrix. This study might be useful for researchers to develop their methods for individualized therapy of patients with Parkinson.
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Abrantes Dias AS, Amaral Pinto JC, Magalhães M, Mendes VM, Manadas B. Analytical methods to monitor dopamine metabolism in plasma: Moving forward with improved diagnosis and treatment of neurological disorders. J Pharm Biomed Anal 2020; 187:113323. [DOI: 10.1016/j.jpba.2020.113323] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 04/16/2020] [Accepted: 04/17/2020] [Indexed: 12/16/2022]
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Burmaoğlu RE, Sağlık Aslan S. A rapid liquid chromatography/tandem mass spectrometry method for simultaneous determination of levodopa, carbidopa, entacapone and their six related compounds in film-coated tablets. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2020; 34:e8782. [PMID: 32170976 DOI: 10.1002/rcm.8782] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 03/10/2020] [Accepted: 03/10/2020] [Indexed: 06/10/2023]
Abstract
RATIONALE A liquid chromatography/tandem mass spectrometry (LC/MS/MS) method has been developed and validated to determine levodopa, carbidopa, entacapone, and corresponding six related substances - levodopa impurity B, levodopa impurity C, methyldopa, methylcarbidopa, entacapone impurity C, and entacapone impurity A - in film-coated tablets for the first time. METHODS Chromatographic separation was achieved with a gradient elution by using a C18 column, a mobile phase containing 0.5% formic acid in water and 0.5% formic acid in methanol. The mobile phase flow rate was 0.5 mL min-1 . The UV detector was set at 280 nm and the triple quadrupole mass spectrometer was used in multiple reaction monitoring (MRM) mode. RESULTS The limit of detection (LOD) and limit of quantification (LOQ) results were 1.3 and 3.94 ng mL-1 for levodopa impurity B; 5.26 and 15.9 ng mL-1 for levodopa impurity C; 0.833 and 2.53 ng mL-1 for methyldopa; 3.31 and 10.0 ng mL-1 for methylcarbidopa; 1.67 and 5.06 ng mL-1 for entacapone impurity C; and 0.61 and 1.86 ng mL-1 for entacapone impurity A. CONCLUSIONS The method was rapid, linear, accurate, and reproducible. The LC/MS/MS method that was developed to determine the related substances and assay of levodopa, carbidopa, and entacapone can be used to evaluate the quality of regular samples in the pharmaceutical industry. It can be also used to test the stability of samples.
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Affiliation(s)
- Rıfat Emre Burmaoğlu
- Faculty of Pharmacy, Department of Analytical Chemistry, Istanbul University, 34116 Beyazıt, Istanbul, Turkey
| | - Serap Sağlık Aslan
- Faculty of Pharmacy, Department of Analytical Chemistry, Istanbul University, 34116 Beyazıt, Istanbul, Turkey
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Hosseini Ghalehno M, Mirzaei M, Torkzadeh-Mahani M. Electrochemical Determination of Levodopa on Carbon Paste Electrode Modified with Salmon Sperm DNA and Reduced Graphene Oxide–Fe3O4 Nanocomposite. RUSS J ELECTROCHEM+ 2019. [DOI: 10.1134/s1023193519100045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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The Determination of Parkinson's Drugs in Human Urine by Applying Chemometric Methods. Int J Anal Chem 2019; 2019:7834362. [PMID: 31360168 PMCID: PMC6652062 DOI: 10.1155/2019/7834362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 06/10/2019] [Accepted: 06/20/2019] [Indexed: 11/17/2022] Open
Abstract
The spectrophotometric-chemometric analysis of levodopa and carbidopa that are used for Parkinson's disease was analyzed without any prior reservation. Parkinson's drugs in the urine sample of a healthy person (never used drugs in his life) were analyzed at the same time spectrophotometrically. The chemometric methods used were partial least squares regression (PLS) and principal component regression (PCR). PLS and PCR were successfully applied as chemometric determination of levodopa and carbidopa in human urine samples. A concentration set including binary mixtures of levodopa and carbidopa in 15 different combinations was randomly prepared in acetate buffer (pH 3.5).). UV spectrophotometry is a relatively inexpensive, reliable, and less time-consuming method. Minitab program was used for absorbance and concentration values. The normalization values for each active substance were good (r2>0.9997). Additionally, experimental data were validated statistically. The results of the analyses of the results revealed high recoveries and low standard deviations. Hence, the results encouraged us to apply the method to drug analysis. The proposed methods are highly sensitive and precise, and therefore they were implemented for the determination of the active substances in the urine sample of a healthy person in triumph.
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Elbarbry F, Nguyen V, Mirka A, Zwickey H, Rosenbaum R. A new validated HPLC method for the determination of levodopa: Application to study the impact of ketogenic diet on the pharmacokinetics of levodopa in Parkinson's participants. Biomed Chromatogr 2018; 33:e4382. [DOI: 10.1002/bmc.4382] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 08/28/2018] [Accepted: 09/07/2018] [Indexed: 11/11/2022]
Affiliation(s)
- Fawzy Elbarbry
- School of Pharmacy; Pacific University; Hillsboro OR USA
| | - Van Nguyen
- School of Pharmacy; Pacific University; Hillsboro OR USA
| | | | - Heather Zwickey
- Helfgott Research Institute; National University of Natural Medicine; Portland OR USA
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Micellar HPLC-UV method for the simultaneous determination of levodopa, carbidopa and entacapone in pharmaceuticals and human plasma. J Chromatogr B Analyt Technol Biomed Life Sci 2018; 1091:36-45. [PMID: 29843067 DOI: 10.1016/j.jchromb.2018.05.030] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 05/13/2018] [Accepted: 05/21/2018] [Indexed: 11/23/2022]
Abstract
A method based on micellar liquid chromatography to quantify levodopa, carbidopa and entacapone in plasma is reported. The sample pretreatment was a simple dilution in a pure micellar solution then filtration and direct injection, without requiring extraction or purification steps. The three drugs were resolved from the matrix in 7 min, using an aqueous solution of 0.1 M sodium dodecyl sulphate-10% n-propanol-0.3 tiethylamine, adjusted at pH 2.8 with 0.02 M orthophosphoric acid as mobile phase, running under isocratic mode at 1.0 mL/ min through VP-ODS column. The detection was done by UV (ultraviolet) absorbance at 225 nm. The method was successfully validated by the International Conference Harmonization guidelines in terms of: selectivity, linearity (r2 > 0.998) over the concentration ranges of 0.025-1.2, 0.05-1.0 and 0.3-2.0 μg mL-1 with limits of detection of 0.01, 6.16 × 10-3 and 0.02 μg mL-1 and limits of quantification of 0.03, 0.02 and 0.07 μg mL-1 for levodopa, carbidopa and entacapone, respectively. The proposed method was applied successfully for quantification of the studied drugs in their different dosage forms. Moreover, the method was further extensive to the quantification of the studied drugs in spiked human plasma and was successfully validated by the guidelines of the European Medicines Agency. The proposed procedures were successfully evaluated to determine the studied drugs in real human plasma. The procedure was found reliable, practical, cost-effective, available, short period, easy-to-handle, low-cost, environmental-friendly, secure, useful for the analysis of numerous samples per day. Lastly, the method was performed to the analysis of incurred, using quality control samples in the same analytical run, with adequate results. Therefore, it can be implementable for custom analysis in clinical laboratories.
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van de Merbel NC, Bronsema KJ, Gorman SH, Bakhtiar R. Sensitivity improvement of the LC–MS/MS quantification of carbidopa in human plasma and urine by derivatization with 2,4-pentanedione. J Chromatogr B Analyt Technol Biomed Life Sci 2017; 1064:62-67. [DOI: 10.1016/j.jchromb.2017.09.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 09/05/2017] [Accepted: 09/07/2017] [Indexed: 10/18/2022]
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MU CL, WU D, LU HF, XIE H, ZHANG QL. Simultaneous and Sensitive Determination of Levodopa and Carbidopa in Pharmaceutical Formulation and Human Serum by High Performance Liquid Chromatography with On-Line Gold Nanoparticles-Catalyzed Luminol Chemiluminescence Detection. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2017. [DOI: 10.1016/s1872-2040(17)61021-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Chi J, Ling Y, Jenkins R, Li F. Quantitation of levodopa and carbidopa in rat plasma by LC–MS/MS: The key role of ion-pairing reversed-phase chromatography. J Chromatogr B Analyt Technol Biomed Life Sci 2017; 1054:1-9. [DOI: 10.1016/j.jchromb.2017.04.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Indexed: 11/28/2022]
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Raut PP, Charde SY, Bishnoi P. Simultaneous estimation of levodopa, carbidopa and 3-oxymethyldopa in rat plasma using HPLC-ECD. Biomed Chromatogr 2016; 30:1696-700. [PMID: 26910491 DOI: 10.1002/bmc.3713] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Revised: 02/08/2016] [Accepted: 02/17/2016] [Indexed: 11/06/2022]
Abstract
The aim of study was to develop a suitable analytical method for simultaneous estimation of levodopa, carbidopa and 3-O-methyl dopa in rat plasma. Chromatographic separation of plasma samples was achieved using a reverse-phase C18 column. The mobile phase used consisted of a mixture of methanol and phosphate buffer (10 mM, pH 3.50) in the ratio of 90:10 v/v. All analytes were estimated by electrochemical detection at +800 mV. The developed method has been validated as per the standard guidelines. Precision study results were found to be satisfactory, with percentage relative standard deviation for repeatability and intermediate precision <3.96 and 6.56%, respectively, for all analytes detected in rat plasma. The developed method in rat plasma was found to be simple, rapid, accurate, precise and specific. The proposed method has been successfully applied for analysis of rat plasma samples obtained during an oral pharmacokinetic study of sustained release pellets of levodopa and carbidopa in rats. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Prashant P Raut
- Industrial Research Laboratory, Department of Pharmacy, Birla Institute of Technology and Science, Pilani, Pilani Campus, Rajasthan, - 333 031, India
| | - Shrikant Y Charde
- Department of Pharmacy, Birla Institute of Technology and Science, Pilani, Hyderabad Campus, Telangana, - 500 078, India
| | - Pradeep Bishnoi
- Industrial Research Laboratory, Department of Pharmacy, Birla Institute of Technology and Science, Pilani, Pilani Campus, Rajasthan, - 333 031, India
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Simultaneous determination of levodopa, carbidopa, entacapone, tolcapone, 3-O-methyldopa and dopamine in human plasma by an HPLC-MS/MS method. Bioanalysis 2015; 7:207-20. [PMID: 25587837 DOI: 10.4155/bio.14.230] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND In this study, we developed and validated a HPLC-MS/MS method capable of simultaneously determining levodopa, carbidopa, entacapone, tolcapone, 3-O-methyldopa and dopamine in human plasma. RESULTS & METHODOLOGY: Chromatographic separation was achieved using a C8 column with a mobile phase consisting of a gradient of water and acetonitrile:methanol (90:10 v/v), both containing 0.1% formic acid. The developed method was selective, sensitive (LD<7.0 ng ml(-1)), linear (r>0.99), precise (RSD<11.3%), accurate (RE<11.8%) and free of residual and matrix effects. The developed method was successfully applied in plasma patients with Parkinson's disease using Stalevo®. CONCLUSION The new method can be used for the clinical monitoring of these substances and applied to adjustments in drug dosages.
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Vilhena RDO, Pontes FLD, Marson BM, Ribeiro RP, de Carvalho KAT, Cardoso MA, Pontarolo R. A new HILIC-MS/MS method for the simultaneous analysis of carbidopa, levodopa, and its metabolites in human plasma. J Chromatogr B Analyt Technol Biomed Life Sci 2014; 967:41-9. [PMID: 25063927 DOI: 10.1016/j.jchromb.2014.06.030] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 06/17/2014] [Accepted: 06/27/2014] [Indexed: 11/19/2022]
Abstract
Monitoring of the plasmatic levels of levodopa (LEV) and carbidopa (CAR) is necessary to adjust the dose of these drugs according to the individual needs of Parkinson's disease patients. To support drug therapeutic monitoring, a method using HILIC mode and LC-MS/MS was developed for the simultaneous determination of carbidopa, levodopa, and its metabolites (3-o-methyldopa (3-OMD) and dopamine (DOPA)) in human plasma. A triple quadrupole mass spectrometry was operated under the multiple reaction-monitoring mode (MRM) using the electrospray ionization technique. After straightforward sample preparation via protein precipitation, an Atlantis HILIC (150 × 2.1 mm, 3 μm, Waters, USA) column were used for separation under the isocratic condition of acetonitrile/water (79:21, v/v) containing 0.05% formic acid and 3 mmol/L ammonium formate and the total run time was 7 min. Deuterated LEV was used as internal standard for quantification. The developed method was validated in human plasma with a lower limit of quantitation of 75 ng/mL for LEV, 65 ng/mL for CAR and 3-OMD, and 20 ng/mL for DOPA. The calibration curve was linear within the concentration range of 75-800 ng/mL for LEV, 65-800 ng/mL for CAR and 3-OMD, and 20-400 ng/mL for DOPA (r>0.99). The assay was accurate and precise, with inter-assay and intra-assay accuracies within ±13.44% of nominal and inter-assay and intra-assay precision≤13.99%. All results were within the acceptance criteria of the US FDA and ANVISA guidelines for method validation. LEV, CAR, 3-OMD and DOPA were stable in the battery of stability studies, long-term, bench-top, autosampler, and freeze/thaw cycles. Samples from patients undergoing treatment were analyzed, and the results indicated that this new method is suitable for therapeutic drug monitoring in Parkinson's disease patients.
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Affiliation(s)
| | | | | | | | | | - Marco André Cardoso
- Department of Pharmacy, Universidade Federal do Paraná, Curitiba, Paraná, Brazil; Pelé Pequeno Príncipe Institute of Research, Curitiba, Paraná, Brazil
| | - Roberto Pontarolo
- Department of Pharmacy, Universidade Federal do Paraná, Curitiba, Paraná, Brazil.
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Raut PP, Charde SY. Simultaneous estimation of levodopa and carbidopa by RP-HPLC using a fluorescence detector: its application to a pharmaceutical dosage form. LUMINESCENCE 2014; 29:762-71. [DOI: 10.1002/bio.2618] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Revised: 08/19/2013] [Accepted: 10/29/2013] [Indexed: 11/08/2022]
Affiliation(s)
- Prashant P. Raut
- Department of Pharmacy; Birla Institute of Technology and Science; Pilani India
| | - Shrikant Y. Charde
- Department of Pharmacy; Birla Institute of Technology and Science; Pilani India
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Sima IA, Casoni D, Sârbu C. SIMULTANEOUS DETERMINATION OF CARBIDOPA AND LEVODOPA USING A NEW TLC METHOD AND A FREE RADICAL AS DETECTION REAGENT. J LIQ CHROMATOGR R T 2013. [DOI: 10.1080/10826076.2013.790765] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Ioana Anamaria Sima
- a Faculty of Chemistry and Chemical Engineering, Babeş-Bolyai University , Cluj-Napoca , România
| | - Dorina Casoni
- a Faculty of Chemistry and Chemical Engineering, Babeş-Bolyai University , Cluj-Napoca , România
| | - Costel Sârbu
- a Faculty of Chemistry and Chemical Engineering, Babeş-Bolyai University , Cluj-Napoca , România
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Junnotula V, Licea-Perez H. Development and validation of a simple and sensitive method for quantification of levodopa and carbidopa in rat and monkey plasma using derivatization and UPLC–MS/MS. J Chromatogr B Analyt Technol Biomed Life Sci 2013; 926:47-53. [DOI: 10.1016/j.jchromb.2013.03.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 02/20/2013] [Accepted: 03/04/2013] [Indexed: 10/27/2022]
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Babaei A, Taheri AR, Aminikhah M. Nanomolar simultaneous determination of levodopa and serotonin at a novel carbon ionic liquid electrode modified with Co(OH)2 nanoparticles and multi-walled carbon nanotubes. Electrochim Acta 2013. [DOI: 10.1016/j.electacta.2012.11.121] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Bartosova Z, Riman D, Jakubec P, Halouzka V, Hrbac J, Jirovsky D. Electrochemically pretreated carbon microfiber electrodes as sensitive HPLC-EC detectors. ScientificWorldJournal 2012; 2012:295802. [PMID: 22654586 PMCID: PMC3361223 DOI: 10.1100/2012/295802] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2011] [Accepted: 01/02/2012] [Indexed: 12/19/2022] Open
Abstract
The paper focuses on the analysis and detection of electroactive compounds using high-performance liquid chromatography (HPLC) combined with electrochemical detection (EC). The fabrication and utilization of electrochemically treated carbon fiber microelectrodes (CFMs) as highly sensitive amperometric detectors in HPLC are described. The applied pretreatment procedure is beneficial for analytical characteristics of the sensor as demonstrated by analysis of the model set of phenolic acids. The combination of CFM with separation power of HPLC technique allows for improved detection limits due to unique electrochemical properties of carbon fibers. The CFM proved to be a promising tool for amperometric detection in liquid chromatography.
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Affiliation(s)
- Zdenka Bartosova
- Department of Analytical Chemistry, Faculty of Science, Palacky University Olomouc, 17 Listopadu 12, 771 46 Olomouc, Czech Republic
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César IDC, Byrro RMD, de Santana e Silva Cardoso FF, Mundim IM, de Souza Teixeira L, Pontes da Silva E, Gomes SA, Bonfim RR, Pianetti GA. Simultaneous quantitation of levodopa and 3-O-methyldopa in human plasma by HPLC–ESI-MS/MS: Application for a pharmacokinetic study with a levodopa/benserazide formulation. J Pharm Biomed Anal 2011; 56:1094-100. [DOI: 10.1016/j.jpba.2011.07.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 07/20/2011] [Accepted: 07/26/2011] [Indexed: 10/17/2022]
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Abbaspour A, Dehghani E, Noori A. Cyclodextrin Host-Guest Recognition Approach for Simultaneous Quantification and Voltammetric Studies of Levodopa and Carbidopa in Pharmaceutical Products. ELECTROANAL 2011. [DOI: 10.1002/elan.201100327] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Issa YM, Hassoun MEM, Zayed AG. APPLICATION OF HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC METHOD FOR THE DETERMINATION OF LEVODOPA, CARBIDOPA, AND ENTACAPONE IN TABLET DOSAGE FORMS. J LIQ CHROMATOGR R T 2011. [DOI: 10.1080/10826076.2011.591024] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Affiliation(s)
- Yousry M. Issa
- a Chemistry Department , Faculty of Science, Cairo University , Giza, Egypt
| | - Mohamed E. M. Hassoun
- b Chemistry Department , Faculty of Science, Beni Seuf University , Beni Seuf, Egypt
| | - Ashraf G. Zayed
- b Chemistry Department , Faculty of Science, Beni Seuf University , Beni Seuf, Egypt
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César IC, Byrro RMD, Santana E Silva Cardoso FF, Mundim IM, Souza Teixeira L, Gomes SA, Bonfim RR, Pianetti GA. Development and validation of a high-performance liquid chromatography-electrospray ionization-MS/MS method for the simultaneous quantitation of levodopa and carbidopa in human plasma. JOURNAL OF MASS SPECTROMETRY : JMS 2011; 46:943-948. [PMID: 21915959 DOI: 10.1002/jms.1973] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A sensitive and fast high-performance liquid chromatography-electrospray ionization-MS/MS method for the simultaneous quantitation of levodopa and carbidopa in human plasma was developed and validated. A simple protein precipitation step with perchloric acid was used for the cleanup of plasma, and methyldopa was added as an internal standard. The analyses were carried out using an ACE C(18) column (50 × 4.6 mm i.d.; 5 µm particle size) and a mobile phase consisting of 0.2% formic acid and acetonitrile (90:10). The triple-quadrupole mass spectrometer equipped with an electrospray source in positive mode was set up in the selective reaction monitoring mode to detect the ion transitions m/z 198.1 → m/z 107.0, m/z 227.2 → m/z 181.0, and m/z 212.1 → m/z 139.2 for levodopa, carbidopa, and methyldopa, respectively. The method was validated and proved to be linear, accurate, and precise over the range 50-5000 ng/mL for levodopa and 3-600 ng/mL for carbidopa. The proposed method was successfully applied in a pharmacokinetic study with a levodopa/carbidopa tablet formulation in healthy volunteers.
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Affiliation(s)
- Isabela Costa César
- Instituto de Ciências Farmacêuticas, Alameda Coronel Eugênio Jardim 53, 74175-100, Goiânia, GO, Brazil.
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Zhao Y, Zhao S, Huang J, Ye F. Quantum dot-enhanced chemiluminescence detection for simultaneous determination of dopamine and epinephrine by capillary electrophoresis. Talanta 2011; 85:2650-4. [PMID: 21962697 DOI: 10.1016/j.talanta.2011.08.032] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Revised: 08/16/2011] [Accepted: 08/16/2011] [Indexed: 10/17/2022]
Abstract
A sensitive method based on quantum dot (QD)-enhanced capillary electrophoresis-chemiluminescence (CE-CL) detection was developed for simultaneous determination of dopamine (DA) and epinephrine (E). In this work, CdTe QD was added into the running buffer of CE to catalyze the post-column CL reaction between luminol and hydrogen peroxide, achieving higher CL emission. Negative peaks were produced due to the inhibitory effects on CL emission from DA and E eluted from the electrophoretic capillary. The decrease in CL intensity was proportional to the concentration of DA and E in the range of 8.0 × 10(-8)-5.0 × 10(-6)M and 4.0 × 10(-8)-5.0 × 10(-6)M, respectively. Detection limits for DA and E were 2.3 × 10(-8)M and 9.3 × 10(-9)M, respectively. Using this method, the levels of DA and E in human urine from healthy donors were determined.
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Affiliation(s)
- Yunsha Zhao
- Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education), College of Chemistry and Chemical Engineering, Guangxi Normal University, Guilin, 541004, China
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Babaei A, Babazadeh M. A Selective Simultaneous Determination of Levodopa and Serotonin Using a Glassy Carbon Electrode Modified with Multiwalled Carbon Nanotube/Chitosan Composite. ELECTROANAL 2011. [DOI: 10.1002/elan.201000755] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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26
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Paik MJ, Nguyen DT, Yoon JH, Cho IS, Shim WY, Kim KR, Cho KH, Choi SD, Lee G. Selective 3,4-Dihydroxyphenylalanine Analysis in Human Urine as Ethoxycarbonyltert-butyldimethylsilyl Derivatives by Gas Chromatography-Mass Spectrometry. B KOREAN CHEM SOC 2011. [DOI: 10.5012/bkcs.2011.32.3.977] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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27
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Kinetic approach for the enzymatic determination of levodopa and carbidopa assisted by multivariate curve resolution-alternating least squares. Anal Chim Acta 2010; 673:33-9. [DOI: 10.1016/j.aca.2010.05.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 05/17/2010] [Accepted: 05/18/2010] [Indexed: 11/24/2022]
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28
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Daneshgar P, Norouzi P, Ganjali MR, Ordikhani-Seyedlar A, Eshraghi H. A dysprosium nanowire modified carbon paste electrode for determination of levodopa using fast Fourier transformation square-wave voltammetry method. Colloids Surf B Biointerfaces 2009; 68:27-32. [DOI: 10.1016/j.colsurfb.2008.09.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Revised: 07/26/2008] [Accepted: 09/05/2008] [Indexed: 10/21/2022]
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29
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Chikagwa-Malunga S, Adesogan A, Sollenberger L, Phatak S, Szabo N, Kim S, Huisden C, Littell R. Nutritional characterization of Mucuna pruriens. Anim Feed Sci Technol 2009. [DOI: 10.1016/j.anifeedsci.2008.03.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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30
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Chikagwa-Malunga S, Adesogan A, Salawu M, Szabo N, Littell R, Kim S, Phatak S. Nutritional characterization of Mucuna pruiriens. Anim Feed Sci Technol 2009. [DOI: 10.1016/j.anifeedsci.2008.03.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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31
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Electrochemical detection of carbidopa using a ferrocene-modified carbon nanotube paste electrode. JOURNAL OF THE SERBIAN CHEMICAL SOCIETY 2009. [DOI: 10.2298/jsc0912443y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A chemically modified carbon paste electrode (MCPE) containing ferrocene (FC) and carbon nanotubes (CNT) was constructed. The electrochemical behavior and stability of the MCPE were investigated by cyclic voltammetry. The electrocatalytic activity of the MCPE was investigated and it showed good characteristics for the oxidation of carbidopa (CD) in phosphate buffer solution (PBS). A linear concentration range of 5 to 600 ?M CD, with a detection limit of 3.6?0.17 ?M CD, was obtained. The diffusion coefficient of CD and the transfer coefficient (?) were also determined. The MCPE showed good reproducibility, remarkable long-term stability and especially good surface renewability by simple mechanical polishing. The results showed that this electrode could be used as an electrochemical sensor for the determination of CD in real samples, such as urine samples.
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PAGANI AP, CABEZÓN MA, IBÁÑEZ GA. Simultaneous Kinetic-Spectrofluorometric Determination of Levodopa and Carbidopa Using Partial Least-Squares Regression. ANAL SCI 2009; 25:633-8. [DOI: 10.2116/analsci.25.633] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Ariana P. PAGANI
- Departamento de Química Analítica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario and Instituto de Química Rosario (IQUIR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
| | - Miguel A. CABEZÓN
- Departamento de Química Analítica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario and Instituto de Química Rosario (IQUIR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
| | - Gabriela A. IBÁÑEZ
- Departamento de Química Analítica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario and Instituto de Química Rosario (IQUIR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
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33
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Alam SM, Karim MM, Lee SH, Wabaidur SM, Chung HY, Choi JH, Kang M. Development of a sensitive flow-injection-chemiluminescence detection method for the determination of laevodopa. LUMINESCENCE 2008; 23:327-32. [DOI: 10.1002/bio.1039] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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34
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Kim WH, Karim MM, Lee SH. Simultaneous determination of levodopa and carbidopa by synchronous fluorescence spectrometry using double scans. Anal Chim Acta 2008; 619:2-7. [DOI: 10.1016/j.aca.2008.01.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Accepted: 01/05/2008] [Indexed: 10/22/2022]
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35
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Grünhut M, Centurión ME, Band BF. PLS Regression in the Spectrophotometric Data for the Simultaneous Determination of Levodopa and Carbidopa in Pharmaceutical Preparations by Using an Enzymatic Stopped‐Flow FIA Technique. ANAL LETT 2007. [DOI: 10.1080/00032710701486249] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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36
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Safavi A, Tohidi M. Simultaneous kinetic determination of levodopa and carbidopa by H-point standard addition method. J Pharm Biomed Anal 2007; 44:313-8. [PMID: 17403592 DOI: 10.1016/j.jpba.2007.02.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Revised: 02/14/2007] [Accepted: 02/16/2007] [Indexed: 10/23/2022]
Abstract
The kinetic H-point standard addition method (HPSAM) was applied to the simultaneous determination of levodopa and carbidopa. The method was based on the difference in the rate of oxidation of these compounds with Cu(II)-neocuproine system and formation of Cu(I)-neocuproine complex at pH 5.5. The absorbance of the Cu(I)-neocuproine complex was monitored at 453 nm. Experimental conditions such as pH, reagent concentrations, ionic strength and temperature were optimized. Simultaneous determination of levodopa and carbidopa was performed in the range of 0.8-4 and 0.2-1.5 microg ml(-1), respectively. The proposed method was applied to the simultaneous determination of levodopa and carbidopa in pharmaceutical samples, and satisfactory results were obtained.
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Affiliation(s)
- Afsaneh Safavi
- Department of Chemistry, Faculty of Sciences, Shiraz University, Shiraz 71454, Iran.
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37
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Vlcková M, Schwarz MA. Determination of cationic neurotransmitters and metabolites in brain homogenates by microchip electrophoresis and carbon nanotube-modified amperometry. J Chromatogr A 2007; 1142:214-21. [PMID: 17223116 DOI: 10.1016/j.chroma.2006.12.040] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2006] [Revised: 12/01/2006] [Accepted: 12/11/2006] [Indexed: 11/24/2022]
Abstract
An electrophoretic method for simultaneous determination of catecholamines and their O-methoxylated metabolites on the microchip as well as in the capillary is presented. A complex separation system employing sodium dodecyl sulfate (SDS) micelles, dendrimers forming a second pseudostationary phase and borate complexation is needed for the satisfactory separation of the selected compounds on the short migration length. A carbon nanotube-modified working electrode has been applied for the sensitive amperometric detection with submicromolar detection limits. The applicability of this new method for the analytics of real samples is demonstrated by analysis of mouse brain homogenate on the microchip and human urine by capillary electrophoresis.
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Affiliation(s)
- Markéta Vlcková
- Department of Chemistry, University of Basel, Spitalstrasse 51, 4056 Basel, Switzerland
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38
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Madrakian T, Mohammadnejad M. Simultaneous Spectrophotometric Determination of Levodopa and Carbidopa in Pharmaceutical Formulations and Water Samples by Using Mean Centering of Ratio Spectra and H-Point Standard Addition Methods. Chem Pharm Bull (Tokyo) 2007; 55:865-70. [PMID: 17541183 DOI: 10.1248/cpb.55.865] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Two spectrophotometric methods are described for the simultaneous determination of binary mixtures of carbidopa and levodopa in pharmaceutical formulations, without prior separation steps, using the mean centering of ratio spectra and H-point standard addition methods (HPSAM). The methods are based on the difference in the absorption spectra for the products of the reaction of carbidopa and levodopa with 4-aminobenzoic acid in the presence of periodate ion at pH 4.0. The methods allow rapid and accurate determination of carbidopa and levodopa. The results showed that the methods were capable to simultaneous determination of 0.30-10.00 microg ml(-1) and 0.50-10.00 microg ml(-1) each of carbidopa and levodopa. The proposed methods were successfully applied to the simultaneous determination of carbidopa and levodopa in pharmaceutical samples.
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39
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Yang Z, Zhang X, Guo H, Gan Y. Simultaneous Determination of Monoamines, Their Precursor Amino Acids, and Related Metabolites in Mice Brain by High‐Performance Liquid Chromatography with a Coulometric Electrode Array System. ANAL LETT 2006. [DOI: 10.1080/00032710600721480] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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40
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Abstract
Detection of biogenic monoamines in nanomolar concentrations is of great importance for probing the brain chemistry and for their analytics in biological fluids. The sensitivity enhancement of amperometric detection of neurotransmitters (NTs) and their metabolites after their electrophoretic separation on a microchip is presented and is based on coupled enzymatic reactions. The current response of the analyte is amplified by cyclic oxidation on a gold electrode mediated by reduced nicotinamide dinucleotide coenzyme and glucose oxidase enzyme present in the electrophoresis buffer. Using this approach, detection limits of about 10 nM for NTs and their metabolites can be reached.
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Affiliation(s)
- Markéta Vlcková
- Department of Chemistry, University of Basel, Basel, Switzerland
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41
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Bergamini MF, Santos AL, Stradiotto NR, Zanoni MVB. A disposable electrochemical sensor for the rapid determination of levodopa. J Pharm Biomed Anal 2005; 39:54-9. [PMID: 15896939 DOI: 10.1016/j.jpba.2005.03.014] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2004] [Revised: 02/17/2005] [Accepted: 03/01/2005] [Indexed: 10/25/2022]
Abstract
Levodopa (L-dopa), the biological precursor of catecholamines, is the most widely prescribed drug in the treatment of Parkinson's disease. The present work presents a proposal for the application of a gold screen-printed electrode an electrochemical sensor for monitoring L-dopa in stationary solution and a flow system. Using the electrooxidation of L-dopa at +0.63 V in acetate buffer pH 3.0 on a gold screen-printed electrode it is possible to obtain a linear calibration curve from 9.9 x 10(-5) to 1.2 x 10(-3) mol L(-1) and a detection limit of 6.8 x 10(-5) mol L(-1). Under amperometric conditions (E(app) = 0.8 V; flow rate = 14.1 mL min(-1); pH 3.0), an analytical calibration graph for l-dopa was obtained from 1.0 x 10(-6) mol L(-1) 6.6 x 10(-4) mol L(-1) with a detection limit of 9.9 x 10(-7) mol L(-1). The method was successfully applied to the determination of L-dopa in commercial dosage forms without any pre-treatment.
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Affiliation(s)
- Márcio F Bergamini
- Departamento de Química Analítica, Instituto de Química, Universidade Estadual Paulista, UNESP, CP 355, Araraquara, SP, Brazil
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42
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Damiani PC, Moschetti AC, Rovetto AJ, Benavente F, Olivieri AC. Design and optimization of a chemometrics-assisted spectrophotometric method for the simultaneous determination of levodopa and carbidopa in pharmaceutical products. Anal Chim Acta 2005. [DOI: 10.1016/j.aca.2005.04.065] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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43
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Funan C, Zhujun Z, Yingxue Z, Deyong H. Microdialysis sampling and high-performance liquid chromatography with chemiluminescence detection for in-vivo on-line determination and study of the pharmacokinetics of levodopa in blood. Anal Bioanal Chem 2005; 382:211-5. [PMID: 15900474 DOI: 10.1007/s00216-005-3162-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2004] [Revised: 01/24/2005] [Accepted: 02/11/2005] [Indexed: 10/25/2022]
Abstract
A simple, reliable, and reproducible method for in-vivo on-line separation and determination of levodopa has been based on microdialysis then high-performance liquid chromatography with chemiluminescence detection. The perfusate is perfused at a flow rate of 5 microL min(-1). The concentration of levodopa in the dialysate is determined on line with a chemiluminescence system. The dialysate sample volume is approximately 20 microL. The response of the system is linearly related to the concentration of levodopa in the range 1 x 10(-8) to 1 x 10(-6) g mL(-1) (r2 = 0.9995) with a detection limit (3sigma) of 3 x 10(-9) g mL(-1) and sample throughput of 12 h(-1); RSD is 2.8% (n = 11). The method has been successfully used to study the pharmacokinetics of levodopa in vivo; the values of the pharmacokinetics parameters Cmax, AUC(0-t) and Tmax were 16.60, 20.92 ng mL(-1), and 90 min, respectively.
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Affiliation(s)
- Chen Funan
- Institute of Analytical Science, Southwest Normal University, Chongqing, 400715, PR China
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Yi SY, Cho HH, Kim HS, Bae ZU. Electrochemical Determination of L-Dopa Using Modified Electrodes with Ni(II)-Macrocyclic Complex. JOURNAL OF THE KOREAN CHEMICAL SOCIETY-DAEHAN HWAHAK HOE JEE 2005. [DOI: 10.5012/jkcs.2005.49.1.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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45
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Simultaneous Derivative Spectrophotometric Determination of Levodopa and Carbidopa in Pharmaceutical Preparations. B KOREAN CHEM SOC 2004. [DOI: 10.5012/bkcs.2004.25.12.1764] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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46
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Pistonesi M, Centurión ME, Fernández Band BS, Damiani PC, Olivieri AC. Simultaneous determination of levodopa and benserazide by stopped-flow injection analysis and three-way multivariate calibration of kinetic-spectrophotometric data. J Pharm Biomed Anal 2004; 36:541-7. [PMID: 15522528 DOI: 10.1016/j.jpba.2004.07.006] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2003] [Revised: 06/23/2004] [Accepted: 07/04/2004] [Indexed: 11/25/2022]
Abstract
The simultaneous determination of levodopa and benserazide in pharmaceutical formulations is described, based on the application of multidimensional partial least-squares regression to the kinetic-spectrophotometric data provided by diode-array detection within a stopped-flow injection method where analytes react with periodate. Flow injection parameters were adequately optimized. Accurate analysis is performed with no sample pre-treatment steps, and with minimum experimental effort. Satisfactory recovery results were obtained on a number of synthetic and commercial samples, in the latter case including the comparison with liquid chromatography measurements.
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Affiliation(s)
- Marcelo Pistonesi
- Laboratorio FIA-Química Analítica, Departamento de Química, Universidad Nacional del Sur, Av. Alem 1253, (B8000CPB) Bahía Blanca, Argentina
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47
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Teixeira MF, Bergamini MF, Marques CM, Bocchi N. Voltammetric determination of L-dopa using an electrode modified with trinuclear ruthenium ammine complex (Ru-red) supported on Y-type zeolite. Talanta 2004; 63:1083-8. [DOI: 10.1016/j.talanta.2004.01.018] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2003] [Revised: 01/29/2004] [Accepted: 01/29/2004] [Indexed: 11/29/2022]
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48
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Abstract
The fast on-chip determination of a range of compounds of relevance in the study and treatment of neurological disorders is demonstrated. These include dopamine and its metabolites methoxytyramine, homovanillic acid, noradrenaline, adrenaline, normetanephrine, and metanephrine, its artificial precursors DOPA and tyrosine; and the related compounds DOPS and CDOPA. Two runs are needed for the determination of these compounds. The enantiomers of adrenaline, noradrenaline, and dopamine can be separated in a buffer containing the novel combination of a cyclodextrin and a dendrimer. The isomers of homovanillic acid, DOPA, CDOPA, methoxytyramine, metanephrine, and normetanephrine, which were found to interact more weakly with cyclodextrins, could be separated in approximately 3 min with a buffer containing a cyclodextrin and a crown ether. To our knowledge, this is the first report of a fast chiral separation of such a complex mixture on an electrophoresis chip. Detection was carried out amperometrically; derivatization of the analytes is not necessary.
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Affiliation(s)
- Maria A Schwarz
- Department of Chemistry, The University of Basel, Spitalstrasse 51, 4004 Basel, Switzerland
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