title: Analysis of potential adulteration in herbal medicines and dietary supplements for the weight control by capillary electrophoresis.
abstract: Four different phytopharmaceutical dosage forms for use in weight control programs were analyzed. Two different ground herbal blends and their correspondent infusions, a capsule and a tincture were investigated for the presence of compounds used as adulterants in these products. A capillary electrophoresis (CE) method was developed and validated. The optimized experimental conditions were: BGE, sodium tetraborate buffer 20mM, pH 9.2, voltage applied 30kV, capillary temperature 25°C, injection sample at 0.5Psi during 5s. Ephedrine, norephedrine, caffeine and furosemide were baseline separated in less than 7min; the migration times were found to be 2.65, 2.90, 3.75 and 6.58min, respectively. The analysis showed in sample 3 concentrations of 0.45±0.03mgg(-1) (ephedrine), 0.33±0.02mgg(-1) (norephedrine), 1.09±0.41mgg(-1) (caffeine) and 0.80±0.17mgg(-1) (furosemide). Caffeine content in samples 1, 2 and 4 was 0.61±0.06mgg(-1), 15.66±1.05mgg(-1) and 2.27±0.13mgml(-1), respectively. Linearity was obtained in the concentration range of 1-1000μgml(-1). Limits of detection (LOD) and quantification (LOQ) were determined as 0.42μgml(-1) and 1.40μgml(-1) (ephedrine), 0.47μgml(-1) and 1.40μgml(-1) (norephedrine), 0.12μgml(-1) and 0.48μgml(-1) (caffeine), 0.22μgml(-1) and 0.73μgml(-1) (furosemide). The common constituents of the samples did not interfere with the potential adulterants. Repeatability was better than 0.24% RSD for the retention time and 1.43% for the peak area. Intermediate precision was tested by changing the capillary, the day of operation and the operator, in all the cases the %RSD was better than 3.06.
authors.affiliation: Universidad Nacional de San Luis, Facultad de Química, Bioquímica y Farmacia, Química Analítica, Chacabuco y Pedernera, San Luis 5700, Argentina.
authors.forename: Valeria
authors.initials: V
authors.lastname: Cianchino
authors.affiliation: Universidad Nacional de San Luis, Facultad de Química, Bioquímica y Farmacia, Química Analítica, Chacabuco y Pedernera, San Luis 5700, Argentina; Universidad Nacional de San Luis, Facultad de Química, Bioquímica y Farmacia, CONICET, Chacabuco y Pedernera, San Luis 5700, Argentina.
authors.forename: Gimena
authors.initials: G
authors.lastname: Acosta
authors.affiliation: Universidad Nacional de San Luis, Facultad de Química, Bioquímica y Farmacia, Química Analítica, Chacabuco y Pedernera, San Luis 5700, Argentina; Universidad Nacional de San Luis, Facultad de Química, Bioquímica y Farmacia, Farmacotecnia, Chacabuco y Pedernera, San Luis 5700, Argentina.
authors.forename: Claudia
authors.initials: C
authors.lastname: Ortega
authors.affiliation: Universidad Nacional de San Luis, Facultad de Química, Bioquímica y Farmacia, Química Analítica, Chacabuco y Pedernera, San Luis 5700, Argentina; Universidad Nacional de San Luis, Facultad de Química, Bioquímica y Farmacia, CONICET, Chacabuco y Pedernera, San Luis 5700, Argentina.
authors.forename: Luis D
authors.initials: LD
authors.lastname: Martínez
authors.affiliation: Universidad Nacional de San Luis, Facultad de Química, Bioquímica y Farmacia, CONICET, Chacabuco y Pedernera, San Luis 5700, Argentina; Universidad Nacional de San Luis, Facultad de Química, Bioquímica y Farmacia, Control de Calidad de Medicamentos, Chacabuco y Pedernera, San Luis 5700, Argentina. Electronic address: roxanag@unsl.edu.ar.
authors.forename: María R
authors.initials: MR
authors.lastname: Gomez
keywords: Adulterants; Capillary electrophoresis; Dietary supplements; Quality control; Weight control drugs