Analysis of potential adulteration in herbal medicines and dietary supplements for the weight control by capillary electrophoresis

CIANCHINO, V., ACOSTA, G., ORTEGA, C., MARTINEZ, L.D., GOMEZ, M.R.

FOOD CHEMISTRY

Elsevier

Año: 2008 vol. 108 p. 1075 - 1081

0308-8146

Four different phytopharmaceutical dosage forms for use in weight control programs were analyzed. Two different ground herbalblends and their correspondent infusions, a capsule and a tincture were investigated for the presence of compounds used as adulterantsin these products. A capillary electrophoresis (CE) method was developed and validated. The optimized experimental conditions were:BGE, sodium tetraborate buffer 20 mM, pH 9.2, voltage applied 30 kV, capillary temperature 25 C, injection sample at 0.5 Psi during5 s. Ephedrine, norephedrine, caffeine and furosemide were baseline separated in less than 7 min; the migration times were found to be2.65, 2.90, 3.75 and 6.58 min, respectively. The analysis showed in sample 3 concentrations of 0.45 ± 0.03 mg g1 (ephedrine),0.33 ± 0.02 mg g1 (norephedrine), 1.09 ± 0.41 mg g1 (caffeine) and 0.80 ± 0.17 mg g1 (furosemide). Caffeine content in samples 1,2 and 4 was 0.61 ± 0.06 mg g1, 15.66 ± 1.05 mg g1 and 2.27 ± 0.13 mg ml1, respectively. Linearity was obtained in the concentrationrange of 1–1000 lg ml1. Limits of detection (LOD) and quantification (LOQ) were determined as 0.42 lg ml1 and 1.40 lg ml1 (ephedrine),0.47 lg ml1 and 1.40 lg ml1 (norephedrine), 0.12 lg ml1 and 0.48 lg ml1 (caffeine), 0.22 lg ml1 and 0.73 lg ml1(furosemide).The common constituents of the samples did not interfere with the potential adulterants. Repeatability was better than 0.24% RSDfor the retention time and 1.43% for the peak area. Intermediate precision was tested by changing the capillary, the day of operation andthe operator, in all the cases the %RSD was better than 3.06.