RESUMO
A simple, sensitive, and novel method has been developed and validated for the separation and simultaneous quantitation of seven structurally different drugs-pipemidic acid and ofloxacin quinolone antibiotics, pseudoephedrine decongestant, piroxicam anti-inflammatory, thiamin, pyridoxine, and cobalamin-in a mixture by capillary zone electrophoresis. Factors affecting the separation were pH, concentration of buffer, and applied voltage. Separation was carried out in < 9 min with a 50 mM sodium tetraborate buffer, pH 10, and an applied voltage of 30 kV in an uncoated silica capillary tube. The carrier electrolyte gave baseline separation with good resolution, reproducibility, and accuracy. Calibration plots were linear over at least three orders of magnitude of analyte concentrations, and the lower LODs were within the range of 1-5 microg/mL. Detection was performed by UV absorbance at 230 nm. The method was validated for the analysis of drugs in pharmaceutical preparations and in urine samples with RSD of 0.5-2.4% and recovery of > 99%.
Assuntos
Antibacterianos/análise , Anti-Inflamatórios/análise , Eletroforese Capilar/métodos , Ofloxacino/análise , Ácido Pipemídico/análise , Quinolonas/análise , Urinálise/métodos , Antibacterianos/urina , Anti-Inflamatórios/urina , Boratos/análise , Boratos/urina , Soluções Tampão , Humanos , Concentração de Íons de Hidrogênio , Modelos Químicos , Ofloxacino/urina , Ácido Pipemídico/urina , Piridoxina/análise , Piridoxina/urina , Quinolonas/urina , Tiamina/análise , Tiamina/urina , Fatores de Tempo , Urinálise/instrumentação , Urina , Vitamina B 12/análise , Vitamina B 12/urinaRESUMO
The lipophilicity of pipemidic, nalidixic and oxolinic acids was determined by forming phospholipidic micelles directly in an electrophoretic capillary. Phosphatidylcholine derivatives, namely L-alpha-dilauroyl phosphatidylcholine (DLPC) or L-alpha-dimiristoyl phosphatidylcholine (DMPC), were added in the run buffer (50 mM phosphate buffer at pH 7.4). To obtain a mixed micelle, phospholipidic derivatives and sodium cholate were together added in the run buffer. Considering the increasing of migration time when phosphatidylcholine derivative is added in the run buffer, Ks can be determined and then quinolones lipophilicity.
Assuntos
Anti-Infecciosos/química , Cromatografia Capilar Eletrocinética Micelar/métodos , Ácido Nalidíxico/química , Ácido Oxolínico/química , Fosfolipídeos/química , Ácido Pipemídico/química , Anti-Infecciosos/análise , Ácido Nalidíxico/análise , Ácido Oxolínico/análise , Fosfolipídeos/análise , Ácido Pipemídico/análiseRESUMO
The sensitized luminescence of europium ion in the complexes with pipemidinic acid is investigated. It was shown that in the result of intramolecular energy transfer from ligand to lanthanide ion the luminescence intensity of the latter increases by 10(10) times. The luminescence properties of the complex were studied and the high sensitive luminescence method for the determination of pipemidinic acid has been developed.
Assuntos
Quelantes/química , Fluorometria/métodos , Ácido Pipemídico/análise , Anti-Infecciosos/análise , Anti-Infecciosos/urina , Európio/química , Humanos , Concentração de Íons de Hidrogênio , Ligantes , Ácido Pipemídico/urina , Controle de Qualidade , Solventes/químicaRESUMO
The present work describes a method based on solid-phase extraction (SPE) and ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for the simultaneous determination of three quinolones (pipemidic acid, oxolinic acid and flumequine) and twelve fluoroquinolones (marbofloxacin, fleroxacin, pefloxacin, levofloxacin, norfloxacin, ciprofloxacin, enrofloxacin, danofloxacin, lomefloxacin, difloxacin, sarafloxacin, and moxifloxacin) in different infant and young children powdered milks. After suitable deproteination of the reconstituted powdered samples, a SPE procedure was developed providing recovery values higher than 84% (RSDs lower than 13%) for all the analytes, with limits of detection between 0.04 and 0.52 µg/kg. UPLC-MS/MS analyses were carried out in less than 10 min. Sixteen infant and young children powdered milk samples of different origin, type and composition bought at Spanish markets were analyzed. Residues of the selected antibiotics were not detected in any of the analyzed samples.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Resíduos de Drogas/análise , Fluoroquinolonas/análise , Fórmulas Infantis/química , Extração em Fase Sólida/métodos , Acetonitrilas , Antibacterianos/análise , Humanos , Lactente , Ácido Oxolínico/análise , Ácido Pipemídico/análise , Análise de Regressão , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Massas em Tandem/métodosRESUMO
An electrochemiluminescence (ECL) based on energy transfer from electro-generated triplet sulfur dioxide to pipemidic acid (PPA) was studied. A weak ECL from triplet sulfur dioxide (3)SO2 * was observed when sulfite was electrochemically oxidized in sulfuric acid solution on a Pt electrode. When PPA was present, the weak ECL was enhanced. The enhanced ECL was attributed to energy transfer from (3)SO2 * to PPA. Based on the enhanced ECL, a flow-injection (FIA) ECL method for the determination of PPA was proposed. The proposed method allowed the measurement of PPA over the range of 1.0x10(-7) to 2.0x10(-5)moll(-1). The detection limit was 3.9x10(-8)moll(-1), and the relative standard deviation for 1.0x10(-6)moll(-1) PPA (n=9) was 1.3%. This method was evaluated by the analysis of PPA in pharmaceutical preparations and urine samples.
Assuntos
Medições Luminescentes/métodos , Ácido Pipemídico/análise , Sulfitos/química , Transferência de Energia , Humanos , Medições Luminescentes/instrumentação , Estrutura Molecular , Oxirredução , Ácido Pipemídico/urina , Sensibilidade e Especificidade , Dióxido de Enxofre/química , Fatores de TempoRESUMO
A flow-injection chemiluminescence (CL) method for the determination of pipemidic acid is described. It is based on energy transfer from excited state peroxynitrous acid to pipemidic acid, in which the excited state peroxynitrous acid is synthesized on-line by the mixing of acid hydrogen peroxide with nitrite in a flow system and the CL is from two excited states of pipemidic acid. The proposed method allows the measurement of pipemidic acid over the range of 2.0 x 10(-7)-2.0 x 10(-5) mol l(-1) . The detection limit is 6.3 x 10(-8) mol l(-1), and the relative standard deviation for 2.0 x 10(-6) mol l(-1) pipemidic acid (n = 9) is 0.9%. This method was evaluated by the analysis of pipemidic acid in pharmaceutical preparations.
Assuntos
Medições Luminescentes/métodos , Ácido Peroxinitroso/síntese química , Ácido Pipemídico/análise , Transferência de Energia , Análise de Injeção de Fluxo/métodos , Peróxido de Hidrogênio/química , Medições Luminescentes/instrumentação , Ácido Peroxinitroso/química , Ácido Pipemídico/química , Nitrito de Sódio/química , Fatores de TempoRESUMO
Capillary zone electrophoresis was employed for the determination of pipemidic acid using an end-column amperometric detection with a carbon fiber microdisk array electrode, at a constant potential of -1.10 V vs. saturated calomel electrode. The optimum conditions of separation and detection were 1.2 x 10(-4) mol/LNaOAc - 8.8 x 10(-4) mol/ LHOAc for the buffer solution, 20 kV for the separation voltage, 5 kV and 10 s for the injection voltage and the injection time. The limit of detection was 1.05 x 10(-7) mol/L or 189 amol (S/N=3). The relative standard deviation was 0.31% for the migration time and 2.0% for the electrophoretic peak current. The method was applied to determining pipemidic acid in human serum.