NEW MATERIAL:A compound of the formula (X is -CH2COOH, -CH2CH2OH, -CH2CH2SO3H).

EXAMPLE: α,β,γ,δ-Tetrakis(1-carboxymethylpyridinium-4-yl)porphyrin.

USE: High-sensitive analytical reagent for metallic ions: it dissolves in water all over the pH region and has a feature that causes no adsorption to glass walls of the instruments.

PREPARATION: α,β,γ,δ-Tetrakis(1-pyridinium-4-yl)porphyrin is made to react with sodium monochloracetate in glacial acetic acid to give the compound of formulaI. The product can solve the problem that the cationic porphyrin is strongly adsorbed on glass walls in neutral and alkaline pH ranges to give erroneous values on determinations.