Determination of Trace Metals in Bulgarian Lavender Oil by Electrothermal Atomic Absorption Spectrometry

An accurate, reliable and fast procedure for the direct Electrothermal Atomic Absorption Spectrometry (ETAAS) determination of number of trace metals (Bi, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Sb) in lavender oil has been developed. Sample preparation consists of simple diluting of lavender oil 1 + 1 or 1 + 2 m/m with isopropanol or 1,4- dioxane. Pyrolytic graphite tubes, W-impreguated tubes and pyrolytic graphite tubes coated with Pt are proposed as atomizers for correct direct ETAAS measurement of studied elements. Calibration curves prepared with aqueous standards diluted in the respective organic solvent are recommended for the quantification of trace elements in lavender oil. the detection limits achieved are well below the maximum permissible concentrations for the studied elements in cosmetic or food products. Within-run and between-run precisions are between 25.7% and 3.10%, respectively at trace levels: Cd (0.5-5 ng/g); Bi, Cr, Cu, Ni, Sb, Pb (1-50 ng/g) and Fe, Mn (20-1000 ng/g). The trace element content in 10 Bulgarian lavender oils is presented.