© 2009 by the Arizona Board of Regents on behalf of the University of Arizona LSC 2008, Advances in Liquid Scintillation Spectrometry

ABSTRACT. Strontium-specific extraction columns from Eichrom Technologies have been used for the determination of 90Sr in wet deposition and in soil in our laboratory. For these determinations, the prepacked 2-mL columns were tested for the breakthrough of strontium with 20 mg of calcium and 2 mg of strontium carrier as well as 40 mg of calcium and 2 mg of stron-tium carrier. The column was suitable for this method with the elution volumes we used for soil and wet deposition and with 20 mg of calcium, but a breakthrough was observed with 40 mg of calcium. Due to the low calcium concentration in wet dep-osition and soil, the 90Sr analysis was possible with 2-mL columns and specific elution volumes. For 90Sr determination in milk samples, the calcium content of the milk is too high. Thus, the method was optimized by reducing the elution volumes to double the calcium concentration, which could be loaded onto the column without breakthrough. With these modifications, a lower limit of detection (LLD) of 0.12 Bq/L could be obtained. A monitoring program of raw cow milk in Austria is con-ducted with regard to the commission recommendation on the application of Article 36 of the Euratom Treaty concerning the monitoring of the levels of radioactivity in the environment for the purpose of assessing the exposure of the population as a whole (2000/473/Euratom). The defined reporting level of 90Sr in milk is 0.2 Bq/L. In this paper, the method is described and results from a monitoring program in Austria between 2003 and 2006 are presented and discussed