STABLE STRONTIUM IN MILK AND MILK POWDER IN THE FEDERAL-REPUBLIC-OF-GERMANY

This paper describes the conditions for ashing milk and milk powder sa mples prior to the detection of stable strontium in an acetylen/air fl ame by atomic absorption spectrometry, The method was used to determin e strontium in samples representative of bulk milk processed by severa l dairies in different regions of Germany throughout the period mid-19 91 to mid-1993. The contents of stable strontium from different geogra phical regions varied strongly. Thus, samples from relatively flat, lo wland northern Germany, from Rheinland-Pfalz, and from Baden-Wurttembe rg contained the smallest concentrations, with mean values ranging fro m 300 and 500 mu g strontium/l milk. Samples from most upland regions (central Germany) and from Bavaria contained slightly greater mean con centrations (about 600 mu g/l) while the maximum concentrations substa ntially exceeded those of the lowland regions. Incongruously, samples from a dairy supplied by milk from the baltic island of Rugen and from the northeastern part of Mecklenburg-Vorpommern (both lowland regions ) contained the largest concentrations of strontium (up to 29,4 mg/kg milk powder corresponding to about 2,75 mg/l in milk). The smallest va lues were found for a baby food based on milk from Schleswig-Holstein (a lowland area). The radioecological importance of stable strontium i n milk and implications of the large variation (more than an order of magnitude) in the concentration of this element in milk are discussed. Moreover, the publication points out the significance of these values to the development of chemical separation methods for the determinati on of strontium radionuclides with new, selective ion exchangers.