OZONE DEGRADATION OF RESIDUAL CARBON IN BIOLOGICAL SAMPLES USING MICROWAVE IRRADIATION

In an attempt to produce complete oxidation of a biological matrix, bo vine liver, ozone was investigated as an additional, potentially non-c ontaminating, oxidizing reagent after nitric acid digestion. Experimen ts were carried out to determine the decomposition efficiency of resid ual carbon species, primarily o-, m- and p-nitrobenzoic acids (NBAs), using ozone. The NBAs were degraded by purging sample digests with ozo ne, while heating the solutions with microwave energy at atmospheric p ressure. The effects of the degradation temperature and solution pH on the ozonation of NBAs mere determined. Solid phase extraction (C-18) was used to extract NBAs from the acid digestate solutions prior to HP LC analysis. Reversed phase HPLC was used to determine NEA concentrati ons in digest solutions. After 2.5 h of purging ozone at 80 degrees C, 33.65 +/- 3.80% o-NBA degradation, 19.39 +/- 1.74% m-NBA degradation, and 26.47 +/- 3.36% p-NBA degradation were obtained.