Determination of the stabilizers antimony, bismuth, and iodate in electroless nickel baths as replacements for lead

Hoveddokument

Besides nickel as main component, an electroless nickel bath contains further major constituents such as electrolyte, buffer as well as reducing and complexing agents. A minor component is the so-called stabilizer. The concentration of this additive ranges from the millimolar to the micromolar level and determines the stability and performance of the bath, for which reason it has to be accurately monitored. This poster describes simple and fast, but sensitive and robust methods for the determination of the stabilizers antimony, bismuth, and iodate in electroless nickel baths.Antimony(III) and bismuth are determined in parallel by anodic stripping voltammetry (ASV) in 0.6 mol/L KCl electrolyte at pH < 2, whereas the determination of iodate is carried out by polarography in 0.1 mol/L sodium citrate electrolyte at a pH value between 2.8 and 3.5. Under the tested conditions, the linear working range in the electroless nickel bath is for antimony β(SbIII) = 0.02…7 mg/L, for bismuth β(Bi) = 0.02…10 mg/L, and for iodate β(IO3-) = 0.3…110 mg/L.