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

Kassa Belay, Abi Tadesse, Tesfahun Kebede


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.


Dry ashing, fenugreek, black cumin, ginger, garlic, atomic absorption spectrometry

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Wahid and S.K Durrani, “Concentration of selected heavy metals in spices, dry fruits and plant nuts,” Plant Foods for Human Nutrition. 39(3) 279-286 ,1989.

Asfaw Z. and M.Tadesse, “Prospects for sustainable use and development of wild food plants in Ethiopia,” Economic Botany. 55 (1):47-62, 2001.

Letchamo, W. and H. Storck, “Spices and Medicinal Plants Trade in Eastern Ethiopia,”

ISHS. Acta Horticulturae. (270): 247-53, 2004,1991. th [5] AOAC (Association of Official Analytical Chemists), Official Methods of Analysis, 16 ed., Arlington, Virginia, USA, 1995.

Mustafa S., T.Mustafa, N.Ibrahim and S.Hayati, “Comparison of digestion procedures for the determination of trace metal contents in spice samples produced in Turkey,” Journal of Food and Drug Analysis, Vol. 12( 3), P.254-258.

Association of Official Analytical chemists/AOAC, “Determination of metals in plant using ICP-OES.” Journal of Association of Official Analytical Chemists.68:499.

Kingston H.M., L.B Jassie ,1986. microwave energy for acid decomposition at elevated temperatures and pressures using biological and botanical samples. Journal of Analytical Chemistry , 58 ( 12) , 2534-2541, 1985.

Tuzen, M., “Determination of some metals in honey samples for monitoring environmental pollution,” Bulletin of Fresenius Environment; 11: 366-370, 2002.

Polkowska-M. H., B.Danko, R.Dybczynski, A. K.-Ammerlaan and P. Bode, “Effect of acid digestion method on cobalt determination in plant materials,” Analytical Chemical Acta 408: 89-95,2000.

Vandecasteele, c., and, C.B., Block,. “Modern method for trace element d etermination ,”John Wiley and Sons Ltd.pp33, 1993.

Tuzen, M., H. Sari and M. Soylak, “Microwave and wet digestion procedures for atomic absorption spectrometric determination of trace metals contents of sediment samples,” Analytical Letters 37: 1949-1960,2004.

Volesky, B and H. May-Phillips, ”Biosorption of heavy metals by Saccharomyces cerevisiae,” Journal of Applied Microbiology Biotechnology. 42: 797-806, 1995.

Wang, JL, “Biosorption of copper (II) by chemically modified biomass of Saccharomyces cerevi siae,” Process Biochemistry. 37:847–50, 2006.

White, T.R and G.E.Douthit, ”Use of microwave oven and nitric acid-hydrogen peroxide digestion to prepare botanical materials for elemental analysis by inductively coupled argon plasma emission spectroscopy,” Journal Association of Analytic Chemistry,68:766-69,1985.


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