EDS data of FKM composite (a) before (b) after immersion for 36 days in different concentrations HNO₃ solution at 80 °C.

Concentration of HNO3 solution	10 wt%		30 wt%		50 wt%
	(a)	(b)	(a)	(b)	(a)	(b)
F	45.6	32.9	46.8	24.2	45.9	23.4
C	28.2	44.3	26.8	48.4	27.2	36.0
O	10.4	15.7	11.1	20.4	11.3	34.3
N	3.3	5.7	3.8	5.3	3.7	5.0
Mg	5.3	0.6	5.6	0.6	4.0	0.7
Ba	5.3	0.5	4.3	0.7	5.6	0.1
S	1.9	0.3	1.6	0.4	2.3	0.5