Novel spectrofluorimetric method for boldine alkaloid determination in herbal drugs and phytopharmaceuticals.

A new green on-line method for Boldine determination (BOL) in herbal drugs and phytopharmaceuticals, using its native fluorescence in acid media (λex=282nm; λem=373nm) has been developed. The presented methodology involves for the first time, a flow injection (FI) strategy using a mini-column of multiwalled carbon nanotubes as retention agent coupled with molecular fluorescence. Different parameters influence as sample pH and flow rate, eluent flow rate and composition; on BOL sensitivity and elution time was investigated by multifactorial techniques. Adequate dynamic calibration range (r2=0.9993) was obtained over a concentration interval of 0.029-27.0µgmL-1 BOL. The limits of detection (LOD) and quantification (LOQ) were 0.008 and 0.029µgmL-1, respectively. The average recoveries in explored samples ranged from 95% to 103%. Under optimized conditions, the throughput sample as high as 30h-1 was achieved with high repeatability performance (99%). The proposed development represents a useful and valuable tool emulating the analytical efficiency of the official methodologies for quality control of herbal and phytopharmaceutical drugs containing BOL. Moreover, this approach shows advantages respect to low cost, simplicity and environmental and analyst friendly.

Monitoring of phenolic compounds for the quality control of Melissa officinalis products by capillary electrophoresis.

INTRODUCTION: Official assays for the quality control of Melissa officinalis L. (Lamiaceae) leaves establish the quantification of total hydroxycinnamic derivatives expressed as rosmarinic acid. OBJECTIVE: The goal of this work was to develop a simple, fast and reliable method for monitoring the phenolic composition in herbs from the Lamiaceae family and for rapidly detecting M. officinalis adulteration or substitution in commercial medicinal samples in Argentina. METHODOLOGY: A capillary zone electrophoresis (CZE) method was performed under the following conditions: the background electrolyte (BGE) consisted of 20 m m sodium tetraborate buffer, pH 9.2; the applied voltage was 25 kV; the capillary and sample temperatures were kept at 25 °C; the hydrodynamic mode was selected for the sample injection (3.45 kPa during 5 s). RESULTS: A CZE method that achieved the separation and simultaneous determination of eight related phenolic compounds in less than 11 min was optimised for application to control quality analysis of M. officinalis-based products. The method was validated according to the US Federal Drug Agency requirements and offers advantages in terms of analysis time, cost and operation. CONCLUSIONS: The proposed methodology can be applied to the standardisation and quality control of plant material and phytopharmaceutical products derived from the Lamiaceae family, as indicated by the results obtained in the analysis of commercial medicinal products in Argentina.

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

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.