MATERIALS AND METHODS
Reagents and instruments
Analytical grade standard of calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), potassium (K), sodium (Na) and zinc (Zn), 70% nitric acid (HNO3) and 69% hydrochloric acid (HCl), double deionized water (DDW) were used. Atomic Absorption Spectrophotometer (AAS), AA 6650 and muffle furnace (LEF 1035) were used for this study.
Fennel seeds and ginger were identified
and confirmed for its specific botanical name by competent taxonomist according to The Flora of Ceylon.14
Fennel seeds were collected from the farms of Myin Gyan (MGN) and Pyin Oo Lwin (POL) townships. Rhizomes of ginger was collected from Mandalay (Mdy) and POL townships, respectively.
Types of compounds present in these samples were tested according to the methods of Harborne, 1998.15
Sample preparation for AAS
Cleaned dried each sample was crushed, powdered and homogenized, using mortar and pestle, and then kept in sampling bags for further analysis.
Digestion of samples
Specified weight (2.5 g) of each
powder sample was placed into
crucible for heating in an oven at 110ºC for 2 hours to remove moisture. These
dried samples were placed in
muffle furnace at 550ºC for 4 hours until the sample became totally ashes.
5 ml of 6 M HNO3 were added to each ash sample to dissolve and digest the contents. Then, each solution was filtered and diluted with DDW up to 50 ml in volumetric flask.16 Standard solutions of each metal were separately prepared from their respective concentration of 1000 mg/ml stock solutions, for the standard calibration curve. Reagent blank determination was used to correct the instrument readings.7
Data were analyzed by using Microsoft Office Excel v. 2007. Results were presented as mean±SE.