Sulphuric acid h2so4

All drugs and chemicals which were of analytical grade quality were sourced from standard pharmaceutical suppliers. Chloroquine diphosphate (C₁₈H₂₆CIN₃∙2H₃PO₄), anthrone reagent, sigmacote, dimethyl sulphoxide (DMSO), Giemsa stain and May-Grunwald solution (Sigma-Aldrich Chemical Company, St Louis, Missouri, USA); calcium chloride (CaCl₂), potassium hydroxide (KOH), sodium sulphate (Na₂SO₄), sodium hydroxide (NaOH), potassium dihydrogen phosphate (KH₂PO₄) and 95% ethanol (C₂H₅OH) (Merck Chemicals (PTY) LTD, Johannesburg, South Africa); diethyl ether (C₄H₁₀O) (NT Laboratory Supplies (PTY) LTD, Johannesburg, South Africa); sulphuric acid (H₂SO₄) (BDH Chemicals LTD, Poole, Dorset, England), halothane (Fluorothane^®, AstraZeneca Pharmaceuticals (PTY) LTD, Johannesburg, South Africa) and insulin ELISA kit (Mecrodia AB, Uppsala, Sweden). S. aromaticum dried flower buds were purchased from Kies Supermarket (Reservoir Hills, Durban, South Africa)

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.