Simultaneous spectrophotometric determinations of cobalt, nickel, and iron

Abstract

2,2′-Dipyridylketone-2-pyridylhydrazone (DPPH) was used for the simultaneous determination of cobalt (0.6–6 ppm) and iron (1–12 ppm). Interferences from nickel, copper, zinc, and manganese were avoided by controlling the pH at 3.5. Isoquinoline-3-aldehyde-2-pyridylhydrazone (IAPH) was used for the simultaneous spectrophotometric determination of cobalt, nickel, and iron. Interferences from copper, zinc, and manganese were avoided by use of EDTA and ammonia.