Dosage des métaux lourds dans les Zygophyllum réputés antidiabétiques

Abstract

Objectives: Among the heavy metals present in our environment, some are toxic; absorbed by plants, they accumulate in tissues and are eliminated slowly; others, the trace elements, essential to the organism, become toxic in strong doses. In the Zygophyllum genus, three Saharan species, Z. geslini, Z. album, and Z sp., are of daily use in traditional medicine as antidiabetics; this repeated use encouraged us to investigate concentrations of heavy metals in these plants (lead, cadmium, iron, arsenic, manganese, zinc, chromium and copper). Methods: - For each plant 2 g of powdered stem, root, leaf and fruit are mineralized (Kjeldahl method). The operation is performed twice. - The analysis of each is done by injection in a furnace (20 μL diluted to the twentieth and 5 μL of matrix modifier). For each element a calibration curve is carried out. - The reading is carried out under the same analytical conditions used for the establishment of the calibration curve. The concentration of the sample is directly read on the respective curves. - Determination by spectrophotometry; simple apparatus for iron, atomic absorption for lead, cadmium, manganese, arsenic and nickel. Results: In the form of tables, they are expressed in μg/g, for the three species. Conclusions: The highest values are: lead, cadmium, manganese and nickel. The chromium rate borders that of brewers' yeast, which is regarded as a good source. The zinc value in Z. geslini is significant. Iron is poorly represented. © 2011 Société Française de Toxicologie Analytique.