Quantitative analysis of boldine alkaloid in natural extracts by cyclic voltammetry at a liquid-liquid interface and validation of the method by comparison with high performance liquid chromatography

TALANTA

卷:83

Article

Camara, C. I.²  Bornancini, C. A.¹  Cabrera, J. L.¹  Ortega, M. G.¹  Yudi, L. M.² 

[1] Univ Nacl Cordoba, Inst Multidisciplinario Biol Vegetal IMBIV CONICE, Dept Farm, Fac Ciencias Quim, RA-5000 Cordoba, Argentina

[2] Univ Nacl Cordoba, Inst Invest Fis Quim Cordoba INFIQC CONICET, Dept Fis Quim, Fac Ciencias Quim, RA-5000 Cordoba, Argentina

关键词: Boldine alkaloids;    Quantification of complex matrixes;    Validation of electrochemical method;    Electrochemistry at liquid/liquid interfaces;    Acid dissociation constant;   

DOI  :  10.1016/j.talanta.2010.10.010

来源: Elsevier

【 摘 要 】

The quantitative determination of boldine alkaloid in boldo leaf extracts by employing cyclic voltammetry, at a liquid/liquid interface as well as the validation of this methodology against the reference method, high performance liquid chromatography (HPLC), are reported in the present paper. The voltammetric analysis was performed successfully and economically using two kinds of liquid/liquid interfaces: water/1,2-dicholoroethane and water/PVC (polyvinyl chloride)-gelled 1,2-dichloroethane. Linear calibration curves in the concentration range of 1.04 x 10(-5) mol L-1 to 5.19 x 10(-4) mol L-1 were obtained with a detection limit equal to (6.1 +/- 0.7) x 10(-5) mol L-1 and the quantitative determination of this alkaloid, in complex matrixes such as boldo leaf extracts, by the electrochemical technique proposed was found to be equal to the values obtained using the standard HPLC method. The validation analysis of this methodology against HPLC demonstrated that accuracy, linearity, limit of detection (LOD), limit of quantification (LOQ), specificity and precision are acceptable. The electroanalytical technique proposed is economical and selective, involves simple equipment and can be applied for the quantitative determination of boldine alkaloid in complex matrixes such as leaf extracts without special drug separation. Moreover, cyclic voltammetry (CV) experiments applied at the liquid/liquid interface under different experimental conditions allowed us to study the transfer mechanism of boldine, and determine a value of pK(a)(w) = 6.90 for protonated boldine, from the variation of voltammetric peak current with pH. (C) 2010 Elsevier B.V. All rights reserved.

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