3-(2-PYRIDYL)-5 6-DIPHENYL-1 2 4-TRIAZI&

Reagent for the determination of Fe and Co, and Ag, Cu, and Ni.

Purify it by recrystallisation from water or by dissolving it in the minimum volume of water, followed by addition of EtOH to precipitate the pure salt. It is light sensitive and complexes with Fe. [Stookey Anal Chem 42 779 1970.]