In the laboratory, bottom ash was collected and sieved with 2 mm mesh sieves to separate the various particle sizes from the fine ash. A 5 g of bottom ash sample was weighed into a 100 mL polytetrafluoroethylene (PTFE) Teflon beaker which was previously acid washed. Two milliliters of 65% nitric acid (HNO3) and 5 mL of 36% hydrochloric acid (HCl) were added to each sample in a fume chamber. The samples were then loaded on a microwave carousel. The vessel caps were secured tightly using a wrench. The complete assembly was microwave irradiated for 20 minutes using milestone microwave lab station ETHOS 900, INSTR: MLS – 1200 MEGA. 6.
Similarly, 5 g of soil samples was digested with 60% perchloric acid (HClO4) (BDH Chemicals Ltd., UK), concentrated nitric acid (HNO3) (BDH Chemicals Ltd., UK), and sulphuric acid (H2SO4) (BDH Chemicals Ltd., UK). Blanks were prepared to check for background contamination by the reagents used.
Similarly, 5 g of soil samples was digested with 60% perchloric acid (HClO4) (BDH Chemicals Ltd., UK), concentrated nitric acid (HNO3) (BDH Chemicals Ltd., UK), and sulphuric acid (H2SO4) (BDH Chemicals Ltd., UK). Blanks were prepared to check for background contamination by the reagents used.