Optimisation of high-performance liquid chromatographic separations with reductive amperometric electrochemical detection: speciation of inorganic and organomercury

Application of chromatographic and electrophoretic methodology to the speciation of organomercury compounds in food analysis

Trace metals such as mercury, especially its organic compounds, are an important risk to the environment and to man due to their accumulation in the food chain. For this reason, the routine determination of the very toxic methylmercury, and of other organic and inorganic mercury compounds in marine and land animals, vegetables, fruits and fresh water is of increasing importance in health and environmental control programmes throughout the world. The majority of speciation methods for organomercurials involve a series of fundamental steps for the identification and quantification of samples of biological origin: extraction or isolation from the matrix; derivatisation and concentration; detection; separation of different species of interest and of interference. Each of these steps, as part of the chromatographic analysis of MeHg and of other organomercurials is revised in this study using food samples.

Reversed-phase high-performance liquid chromatographic study of thimerosal stability in Cuban recombinant hepatitis B vaccine

Non-degraded thimerosal was determined in the presence of its decomposition products by directly assaying recombinant hepatitis B vaccine using a reversed-phase liquid chromatographic method. Methanol-water-orthophosphoric acid (65:35:0.9, v/v/v) was used as the eluent. Salicylic acid was employed as an internal standard. The calibration graph was linear (r = 0.99995) up to 2.5 micrograms of thimerosal. Interference from aluminium hydroxide was eliminated by centrifugation. Good stability of thimerosal in the hepatitis B vaccine was demonstrated. The results obtained were in agreement with the recently proposed mechanism of degradation.