Complexation of Co (II) and Spectrophotometric Determination of the complex using 5-Nitrosalicylaldehyde semicarbazone (NSS) as an Analytical Reagent

5-nitrosalicylaldehyde semicarbazone (NSS) is proposed as a new sensitive reagent for the sensitive
extractive spectrophotometric determination of Co (II). NSS reacts with Co (II) in the pH range 8.0 to 8.4 to
form a coloured complex, which was well extracted into Iso Amyl Alcohol The absorption spectrum of Co (II)
NSS complex in Iso Amyl Alcohol shows maximum absorbance at 417 nm. It was observed that the colour
development was instantaneous and stable for 48 hrs. The system obeyed Beer’s law up to 0.5 to 3.0 µg /
cm
3
. The molar absorptivity calculated was found to be 2.86 * 104
lit mol-1
cm
-1
and the sensitivity of the
method as defined by sandal’s was 1.0 * 10-4
μg/cm2
. The composition of the extracted species was
determined by Job’s Continuous variation method and Mole ratio method was found to be 1:4. It may be
satisfactorily applied for the determination of Co (II) with present method.