Abstract:
Milk is an excellent source of most essential minerals for human, especially in infancy and
childhood where bone mass growth is in a critical phase. This study was aimed to
determine23wfede32the level of selected essential (Fe, Ca and Mn) and non-essential (Pb and
Cd) metals in Debre Libanos wereda, North Shewa Zone, Oromia, Ethiopia. Cows’ milk
samples were collected from six sites of two different feeding styles. These are feeding in the
house and the other one feeding field grass exclusively. The collected samples were preserved
in a deep freezer (-20℃) until analysis. The milk samples were digested by the wet digestion
method using HNO3, HClO4and H2O2in a ratio of 7:1:2v/v for the determination of the level of
Fe, Ca, Mn, Pb and Cd elements using Inductively Coupled Plasma-Optical Emission
Spectrometer (Arcos SOP-ICP-OES, Model ARCOS FHS12).The levels (mg/L) of Ca, Mn
and Fe were 754.360, 0.508 and 0.914 for in-house feeding and 839.20, 0.49 and 0.45for field
feeding cows’ milk samples, respectively. Pb and Cd were below detection limits in both style
of feeding cows’ milk samples. The method was validated by spiking the samples resulting
recoveries ranging from 84.84 - 110.23 and 101.136- 122.723 % for house and field feed
cows’ milk samples, respectively. According to the recommended by WHO for milk sample,
the concentrations of calcium in both field and house feed cows’ milk was less than the
recommended values, and manganese and iron were above the recommended values of
WHO/FAO. Except calcium, the levels of iron and manganese infield feeding cows’ milk
sample were higher than that of in-house feeding.
KEY WORDS: Essential and non-essential metals, house and field feed Cow’s Milk, ICPOES
