Rapid Microwave Digestion Procedures for the Elemental Analysis of Alloy and Slag Samples of Smelted Ocean Bed Polymetallic Nodules

Table 8

Conventional digestion versus developed microwave digestion.

S. No.	Parameter	Conventional digestion	Microwave digestion
1	Sample weight	0.5 gram	0.1 gram
2	Acid requirement	40 ml 1 : 1 HCl, 10 mL HNO3 and 10 ml HClO4	10 mL HCl and 3.5 mL HNO3
3	HClO4 requirement	Yes	No
4	Digestion time	Total 8-9 h.	40 minutes digestion time and 10 minutes ventilation time required. Additional 20 minutes is required for loading & unloading of digestion vessels in digester.; So, total time required is 1 h. 10 min.
5	Time required for analysis of radicals	Time requirement for analysis of radicals is same irrespective of method of digestion