Dong Kim Nguyen, Ngân Thi kim Lâm



Abstract: A Graphite Furnace - Atomic Absorption Spectrophotometry (GF-AAS) for the quantification of cadmium (Cd) and lead (Pb) in dried stevia leaves were developed and validated. The method was validated for some parameters, namely linearity and range, precision, accuracy, Limit of Detection (LoD) and Limit of Quantification (LoQ), according to International Conference on Harmonization (ICH). The developed method was linear over the concentration ranging 0 - 2 µg/L (Cd) and 0 – 20 µg/L (Pb). The correlation coefficient (r) obtained for two metal are higher than 0.995. Limit of detection (LOD) of Cd and Pb  was 0.12 µg/L, 0.33 µg/L. The recovery and repeatability in this method were good enough for determining these heavy metals in dried stevia leaves sample.The developed method has been applied successfully for determination of Cd and Pb levels in dried stevia leaves in Vietnam.

Keywords: Stevia, Atomic Absorption Spectrophotometera (AAS), recovery, detection limit, validation.


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