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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Analysis of oxybutynin and N-desethyloxybutynin in human urine by dispersive liquid-liquid microextraction (DLLME) and capillary electrophoresis (CE)

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Moreira, B. J. [1] ; Borges, K. B. [2] ; de Oliveira, A. R. M. [3] ; de Gaitani, C. M. [1]
Total Authors: 4
[1] Univ Sao Paulo, Dept Ciencias Farmaceut, Fac Ciencias Farmaceut Ribeirao Preto, BR-14040903 Ribeirao Preto, SP - Brazil
[2] Univ Fed Sao Joao Del Rei, Dept Ciencias Nat, BR-36301160 Sao Joao Del Rei, MG - Brazil
[3] Univ Sao Paulo, Dept Quim, Fac Filosofia Ciencias & Letras Ribeirao Preto, BR-14040901 Ribeirao Preto, SP - Brazil
Total Affiliations: 3
Document type: Journal article
Source: ANALYTICAL METHODS; v. 7, n. 20, p. 8763-8770, 2015.
Web of Science Citations: 5

A dispersive liquid-liquid microextraction (DLLME) procedure combined with capthary electrophoresis/diode array detection (CE/DAD) was developed and applied to the determination of oxybutynin (OXY) and N-desethyloxybutynin (DEO) in human urine. The electrophoretic analyses were performed using a 50 mu m i.d. fused silica uncoated capthary with an effective length of 36.5 cm and a 50 mmol L-1 solution of triethylamine, pH 3.0, as the background electrolyte. The temperature was set at 30 degrees C and a constant voltage of +30 kV was applied. Some experimental parameters that affect DLLME's extraction efficiency, such as the type and volume of the extraction and disperser solvents, extraction time and pH, were studied and optimized. The optimal DLLME conditions were found using the following method: 2.5% (w/v) NaCl was added to 5.0 mL of urine, the pH was adjusted to 11.0 and 140 mu L of carbon tetrachloride as the extraction solvent and 260 mu L of acetonitrile as the disperser solvent were quickly added. The performance criteria for linearity, sensitivity, precision, accuracy, recovery and stability have been assessed and they were within the Guidance for Industry: Bioanalytical Method Validation. The mean extraction recoveries for OXY and DEO were 71.4% (SD 6.4%) and 60.9% (SD 8.5%), respectively. The method showed linearity over the concentration range of 90-300 ng mL(-1) and 187.5-750 ng mL(-1), with correlation coefficients of 0.990 and 0.998 for OXY and DEO, respectively. Intra-day and inter-day precision and accuracy assays for these analytes were studied at three concentration levels and were lower than 15%. (AU)

FAPESP's process: 10/17632-1 - Applications of capillary electrophoresis in the areas clinical, therapeutic and biotechnology
Grantee:Cristiane Masetto de Gaitani
Support type: Regular Research Grants