Abstract:
In this study, the levels of fluoride in selected commercial Khat (Catha edulis Forsk) of Jimma
Town, Ethiopia have been investigated using fluoride ion selective electrode. Khat samples were
collected from different local Khat shops available in the Town. The collected samples were
transported to laboratory and prepared for analysis by taking the chewable parts only, i.e., the
youngest leaves and tips of the samples were considered for analysis of both the water soluble
and the total fluoride contents. Determination of the water-soluble fluoride content of each
sample was carried out by soaking the chopped Khat leaves and tips in distilled water and stirred
for five minute. Whereas, determination of the total fluoride content was performed by ashing
the dried Khat leaves and tips using muffle furnace. For quantitative determination an external
calibration curve which was constructed from seven point fluoride concentration levels was used.
Recovery studies were conducted to test the suitability of the method used for the determination
of fluoride in studied matrix and was found to be in the range of 88-to-112 %. The content of
fluoride in fresh unwashed and washed leaves as well as in fresh unwashed and washed tips
samples were found ranging from 0.056 - 0.046 µg /g and 0.041 0.049 µg /g as well as 0.037 -
0.045 μg/g and 0.034 – 0.041 μg/g and in dried leaves and tips samples studied were in the range
of 3.35 - 5.30 µg/g and 2.66 - 3.87 µg /g, respectively. Furthermore, the obtained level of
fluoride was compared with the reported literature values of other area Khat as well as different
guidelines. The study findings, revealed the presence of significant difference in the fluoride
level between the Khat leaves and Tips as well as between the unwashed and washed fresh
samples. Generally, the observed concentrations of both water soluble and total fluoride in the
studied Khat samples were below the WHO guideline for human daily safe intake of fluoride.
