Ev. Alonso et al., AUTOMATIC-DETERMINATION OF COBALT AT THE SUBMICROGRAM PER MILLILITER LEVEL USING A FLOWTHROUGH SPECTROPHOTOMETRIC SENSOR, Talanta, 43(11), 1996, pp. 1941-1947
A flowthrough spectrophotometric sensor for the determination of cobal
t at the nanogram per millilitre level using pyridoxal 4-phenylthiosem
icarbazone as reagent and integrated preconcentration and detection in
the flow cell is proposed. The method is highly selective for cobalt(
II); it features detection and determination limits of 0.02 and 0.06 m
u g ml(-1) respectively, and a linear range of at least 0.04-18 mu g m
l(-1). The method is subject to very few interferences because the str
ongly acidic medium used prevents the formation of most complexes of t
he reagent with other metal ions. The method was applied to the determ
ination of cobalt in pharmaceutical preparations.