Concentration and distribution of silicon in uremic serum and its relation to aluminium levels

The performance of inductively coupled plasma atomic emission spectrometry and electrothermal atomic absorption spectrometry (ETAAS) for the determination of silicon concentration in serum samples was evaluated. Total silicon and aluminium levels in the same uremic sera were investigated using ETAAS. Increased levels were found for both elements (mean 893±300 and 39.7±21 µg l–1, respectively) in these patients as compared with reference values. Nevertheless, no significant correlation was observed between higher or lower silicon and aluminium concentrations in those samples (r=–0.012; p<0.05). Ultramicrofiltration and gel filtration techniques were used to study silicon distribution in serum in an attempt to correlate these values with aluminium distribution. Different partition of each of these elements between serum fractions of high and low relative molecular mass was observed. Moreover, silicon was found to be partly associated with serum proteins. In the light of the results no clear relationship between silicon and proteins, and silicon and aluminium was found.