NMR analysis of the iron ligand ethylenediaminedi(o-hydroxyphenyl)acetic acid (EDDHA) employed in fertilizers.
The exceptional efficiency of the iron chelate of ethylenediaminedi(o-hydroxyphenyl)acetic acid (o,o-EDDHA) in correcting iron chlorosis in plants and the medical applications of various metallic chelates of this compound have long been recognized. As commercial preparations of o,o-EDDHA usually contain impurities, a method for their detection is proposed. By using one- and two-dimensional nuclear magnetic resonance two impurities were identified. The structure of one of these compounds was assigned to an isomer of EDDHA containing at least one p-hydroxyphenyl moiety. The structure of the other impurity was tentatively assigned to a byproduct of the EDDHA synthesis: 2,6-di[CH(COOH)NHCH(2)CH(2)NHCH(COOH)Ar]phenol (Ar = hydroxyphenyl). Both compounds were also detected in the EDDHA extracted from a commercial iron fertilizer.
Cremonini
M A
MA
Department of Food Sciences, University of Bologna, Via Ravennate 1020, 47023 Cesena, Italy. mac@foodsci.unibo.it
Alvarez-Fernández
A
A
Lucena
J J
JJ
Rombolà
A
A
Marangoni
B
B
Placucci
G
G
D005029:Ethylenediamines / Q000032:analysis*; D005308:Fertilizers / Q000032:analysis*; D007502:Iron Chelating Agents / Q000032:analysis*; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy / Q000379:methods
D005029:Ethylenediamines; D005308:Fertilizers; D007502:Iron Chelating Agents; C011813:ethylenediamine-N,N'-bis(2-hydroxyphenylacetic acid)