90Strontium

Silant ev et al. [94] have described a procedure for the determination of 90strontium in small volumes of seawater. This method is based on the determination of the daughter isotope 90yttrium. The sample is acidified with... 

Chassery et al. [97] studied the 87Sr/86Br composition in marine sediments, observing excellent agreement between results obtained by ICP-MS and thermal ionisation mass spectrometry. Low level a-spectrometry with lithium drifted germanium detectors has been used to determine 90strontium in seawater [59]. 

Martin [10] determined 89strontium and 90strontium in soil using total sample decomposition. 

Strontium is usually determined by separation and counting of its yttrium daughter. If the strontium fraction from which yttrium is separated has been adequately purified, the yttrium can be separated as a hydroxide [ 15]. Otherwise the yttrium must undergo further purification such as solvent extraction. A method for the extraction of yttrium into bis(2-ethylhexyl)phosphoric acid from dilute hydrochloric acid has been reported by Butler [18]. Weaver and Kapplemann [19] reported the extraction of yttrium as well as the triva-lent lanthanides into bis(2-ethylhexyl)phosphoric acid from a solution of acetic acid and sodium diethylenetriaminepentaacetate. 

The procedure described by Martin [10] has a detection limit for 90strontium for a 10-gram sample and a /3-counting blank of 250 counts per 100 min of 1 x 10 7 xgCi/g. The detection limit for 89strontium varies with the relative activities of 89strontium and 90strontium in the sample. 

The National Bureau of Standards [57] has issued standard reference materials for a-emitting radionuclides in soils. These include 60cobalt, 90strontium, 90yttrium, tritium, and 106ruthenium. 

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