HPLC analysis of thimerosal and its degradation products in ophthalmic solutions with electrochemical detection.
A reverse-phase high-performance liquid chromatographic assay using amperometric detection on a glassy-carbon electrode has been developed for analysis of thimerosal and its main degradation products, thiosalicylic acid and dithiodibenzoic acid, in ophthalmic formulations. A potential value of 0.9 V vs. Ag/AgCl was chosen for simultaneous detection of thimerosal and thiosalicylic acid, obtaining limits of detection of 1.0 and 0.2 ng injected, respectively. A potential value of 1.2V was applied for simultaneous determination of all three compounds studied, obtaining in this case limits of detection of 3,4 and 4 ng injected for thimerosal, thiosalicylic acid and dithiodibenzoic acid, respectively. The results obtained reveal the utility of the HPLC method in quality control of commercial products containing thimerosal with good detectability.
Procopio
J R
JR
Department of Analytical Chemistry and Instrumental Analysis, Autonoma University of Madrid, 28049 Madrid, Spain.
da Silva
M P
MP
Del Carmen Asensio
M
M
Sevilla
M T
MT
Hernandez
L
L