Determination of lead and tin by anodic stripping voltammetry

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In most electrolytes the peak potentials of lead and tin are so close together, that a voltammetric determination is impossible. Difficulties occur especially if one of the metals is present in excess.
Method 1 describes the determination of Pb and Sn. Anodic stripping voltammetry (ASV) is used under addition of cetyltrimethylammonium bromide. This method is used when:
• one is mainly interested in Pb
• Pb is in excess
• Sn/Pb ratio is not higher than 200:1
According to method 1, Sn and Pb can be determined simultaneously if the difference in the concentrations is not too high and Cd is absent.
Method 2 is applied when traces of Sn and Pb are found or interfering TI and/or Cd ions are present. This method also uses DPASV in an oxalate buffer with methylene blue addition.