Minicomputer-controlled,background-subtracted anodic stripping voltammetry: evaluation of parameters and performance

A new minicomputer-controlled anodic stripping voltammetry technique is described. The technique uses differential voltammetry at one electrode, and uses a rapid data-averaging algorithm to avoid the need for scan averaging; this allows excellent sensitivities and short analysis times, with adequate reproducibilities. Both linear-scan and staircase waveforms are discussed in conjunction with the technique, and the approximate Roe—Toni theory for linear-scan voltammetry is shown to apply. The system response is investigated for film thickness, scan rate, deposition time, electrode rotation rate, and metal concentration. Results were used to optimize the sensitivity of the technique. The metal ions Cd, Pb and Cu could be determined in solutions as dilute as 1–10 pg/ml^-1 in 15 min. The viability of the technique in solutions showing a large background is also discussed, and a comparison is made with scan-averaged techniques.