Surface active materials, such as proteins, are
known to interfere in stripping voltammetry. Wang
and Lu reported significant interference of gelatin on
the tungsten determination (11). To test the effect of
proteins on the molybdenum and tungsten determination,
bovine serum albumin (67 kDa) was used as a
model system. Since adsorption is the essential process
in this determination, adsorption of the metal to the
protein surface will interfere significantly with the determination.
Proteins may also adsorb at the mercury
surface and thus interfere at the electrode. As can be
seen in Fig. 4, BSA was found to result in reduced peak
currents from 5 nM Mo and 5 nM W if present in
concentrations above 2 mg/ml (529.9 nM, sixfold molar
excess). Although at high concentrations of protein the