Simultaneous Determination of Mineral Nutrients and Toxic Metals in M. stenopetala from Southern Ethiopia: A Comparative Study of Three Cultivating Areas Using MP-AES

Table 2

Optimization of digestion time for 0.5 g of leaf and seed samples at a constant acid mixture volume and digestion temperature.

Volume ratio (HNO3 : HClO4 : H2O2)	Total volume (mL)	Temp. (°C)	Digestion time (hrs)	Observations
2.5 : 0.75 : 0.5	3.75	300	1:00	Yellow solution
2.5 : 0.75 : 0.5	3.75	300	1:30	Light yellow
2.5 : 0.75 : 0.5	3.75	300	2:00	Colorless and turbid
2.5 : 0.75 : 0.5	3.75	300	2:30	Clear and colorless
2.5 : 0.75 : 0.5	3.75	300	3:00	Clear and colorless

The optimal digestion time.