Table 3.

The reaction yield (%) of the products that formed from alanine at temperatures of 50, 90, and 120 °C for 35 days in the presence of metal ferrites.

Catalyst	% Yield of the Products Formed When Alanine Was Heated at 50, 90 and 120 °C for 35 Days
	DKP(Ala)			(Ala)2
	50 °C	90 °C	120 °C	50 °C	90 °C	120 °C
No catalyst	0.02	0.07	0.11	n.d	n.d	n.d
NiFe2O4	1.78	13.11	14.81	6.11	15.21	8.01
CoFe2O4	1.45	9.23	10.71	1.71	11.81	7.89
CuFe2O4	1.01	8.81	9.08	1.40	10.1	6.54
ZnFe2O4	0.81	4.78	6.21	1.11	7.57	4.11
MnFe2O4	0.17	3.89	4.56	* n.d	trace	trace

* n.d = not detected.