Indirect cathodic-stripping voltammetric determination of ceftazidime as a mercury salt Original Research Article

At accumulation potentials close to +0.1 V at a hanging mercury drop electrode, ceftazidime is accumulated at pH 9.5, probably in a hydrolysed or otherwise chemically altered form, in an anodic process to give an adsorbed mercury salt. The accumulation of this mercury salt allows the indirect cathodic-stripping voltammetric determination of ceftazidime using the reduction peak of the mercury salt at −0.70 V. The high sensitivity of the method coupled with high sample dilution allows ceftazidime to be determined in milk samples at the 28 μg ml−1 level without prior separation. In order to determine lower levels of ceftazidime in milk (ca. 10 ng ml−1) a separation process would be required.