Patent ID: 7358363

Claim:
A zinc complex represented by a formula (I-0) wherein each R is the same or different from each other and each R represents H; an alkyl group having 1 to 16 carbon atoms; an acyl group, a carboxyalkyl group, an acylalkyl group, a carbamoylalkyl group, a cyanoalkyl group, a hydroxyalkyl group, an aminoalkyl group or a haloalkyl group, wherein an alkyl portion of said acyl group, said carboxyalkyl group, said acylalkyl group, said carbamoylalkyl group, said cyanoalkyl group, said hydroxyalkyl group, said aminoalkyl group and said haloalkyl group has 1 to 16 carbon atoms; a carboxyl group; a carbamoyl group; a hydroxyl group; a cyano group; an amino group; or a halogeno group, provided that the case where each R is hydrogen is excluded, the zinc complex is capable of capturing a substance having one or more anionic substituents.