NEW COATED-WIRE COBALT(II)-SELECTIVE ELECTRODE BASED ON THE BENZALKONIUM TETRATHIOCYANATOCOBALTATE(II) ION-PAIR

A cobalt-selective electrode based on the benzalkonium tetrathiocyanatocobaltate(II) ion pair is described. The response is Nemstian (slope 29.3 mV pCo) in the cobalt concentration range 10-1-10-4 M in solutions with a constant ionic strength of 3.0 M made up with KSCN at 25°C. The electrode is suitable for end-point detection in titrations of cobalt(II) with EDTA as well as for direct potentiometric determinations of cobalt(II), even in the presence of large amounts of several metal ions (Ni2+, Fe2+, Mn2+, Mg2+, Ca2+, Ba2+) and anions (HCO3-, Br-, I-, NO3-, SO42-). © 1979.