The determination of nickel in the presence of copper and iron interference can be advantageously effected by the pH-gradient
procedure in FIA system in which the PUF mini-column is applied
for on line removal step of these metal interferences . Outstandingly, nickel can be determined with great accuracy,high sensitivity and significant precision and furthermore,this optimum
method can be applied for nickel determination in piercing
jewelries such as brass,steel and bronze etc. It is interesting to report that the Ni(II) complexes formation was produced efficiently
under the optimum condition of the pH-gradient technique
without using the buffer pH controlling system. Especially,the
nickel determination by pH gradient technique can be expediently
performed and economized the amounts of chemical reagent sand
samples.