abstract |
The present invention is a method for colorimetrically determining a metal in a sample using a chelating coloring agent, characterized by coexistence of a masking agent for iron, copper or nickel. Also, the present invention is a reagent for colorimetrically determining a metal in a sample using a chelating coloring agent, characterized by inclusion of a masking agent for iron, copper and/or nickel. Further, the present invention is a masking agent for iron, copper and/or nickel and a method for reducing positive errors due to iron, copper or nickel contained in a sample. |