1,10-Phenanthroline, Monohydrate, Reagent, ACS is a tricyclic nitrogen heterocyclic compound that reacts with metals such as iron, nickel, ruthenium, and silver to form strongly colored complexes. This property provides an excellent and sensitive method for determining these metal ions in aqueous solution. 1,10-Phenanthroline is also an inhibitor of metallopeptidases. Inhibition of the enzyme occurs by removal and chelation of the metal ion required for catalytic activity, which leaves an inactive apoenzyme. As an ACS grade quality reagent, its chemical specifications are the de facto standards for chemicals used in many high-purity applications and typically designate the highest quality chemical available for laboratory use. Spectrum Chemical manufactured Reagent ACS grade products meet the toughest regulatory standards for quality and purity.