Patent ID: 7820449

Claim:
A test piece for creatinine measurement comprising: a compound expressed by the following formula (1) where R 1 represents H, SO 3 X or COOX, R 4 and R 6 represent OH, SO 3 X, or COOX and are either the same or different, R 2 , R 3 , R 5 and R 7 represent H, OH, Cl, Br, I, NO 2 , NO, or CH 3 and are either the same or different, and Xs in the R 1 , R 4 and R 6 represent H, Na, K, or NH 4 and are either the same or different, and a transition metal or its salt that forms a colored complex with the compound, wherein the transition metal is Pd(II), wherein the compound and the transition metal are included in a porous material.