Mc. Alvarez-ros et al., Catalytic modification of gallic acid on a silver surface studied by surface-enhanced Raman spectroscopy, J RAMAN SP, 32(2), 2001, pp. 143-145
We studied the chemical changes undergone by gallic acid (GA) when adsorbed
on a colloidal silver surface by means of surface-enhanced Raman spectrosc
opy (SERS). The application of the SERS technique allows a remarkable Raman
sensitivity enhancement and the strong fluorescence quenching needed to ch
aracterize the highly colored products of GA oxidative condensation. We fou
nd that GA can undergo a ring opening, a polymerization of aromatic rings o
r a combination of both mechanisms, leading to the formation of humic-like
substances. The influence of pH and light irradiation on these catalytic pr
ocesses was investigated in relation to the importance of these mechanisms.
Copyright (C) 2001 John Wiley & Sons, Ltd.