perchloric acid (60%) and sulphuric acid (10:4:1). Lanthanum chloride (1% v/v) was added to acid solutions of the ashes and to the standard solutions to minimize possible interference in the determinations of the minerals.
perchloric acid (60%) and sulphuric acid (10:4:1). Lanthanum chloride (1% v/v) was added to acid solutions of the ashesand to the standard solutions to minimize possible interference in the determinations of the minerals.