Validation of a Method for Determining Heavy Metals in Some Ethiopian Spices By Dry Ashing Using Atomic Absorption Spectroscopy

ABSTRACT: The optimal conditions for determination of Pb, Cd and Cr in spices sample by FAAS after dry mineralization 1g spice samples for 5hr in a temperature of 500 °C followed dissolution in 4 mL HNO in Fenugreek, Black cumin, garlic and 3 ginger. Working linear ranges are given: for Cd, 0-6mg/l, for Cr, 0.2-1mg/l and for Pb, 2-20μg/l. Found detection limits are 0.2mg/l, 0.13mg/l and 0.02μg/l for Cd, Cr and Pb, respectively. The result obtained Lead in Fenugreek, Black cumin, garlic an d ginger ranged from 0.0126 to 0.0155, 0.0205 to 0.0254, 0.0046 to 0.0066 and 0.0161 to 0.0178 mg/kg respectively. Cadmium is detected only in Fenugreek in the ranged of ND to 0.0175mg/kg where as Chromium in Fenugreek, Black cumin, Garlic and Ginger ranges from 0.0187 to 0.0219, 0.0134 to 0.0152, 0.0014 to 0.0016 and 0.0258 to 0.0346 mg/kg respectively which is under the values recommended for concentration levels present in the analyzed samples.