Tait D, Wiechen A
Institute of Chemistry and Physics, Federal Dairy Research Centre, Kiel, Germany.
Sci Total Environ. 1993 Mar 25;130-131:447-57. doi: 10.1016/0048-9697(93)90099-r.
This paper describes a method of reproducibly recovering strontium (Sr) in 90.4% yield from 2-litre samples of raw milk in an analysis time of 5-8 h. All species which may interfere with the measurement of 89Sr and 90Sr are effectively removed; decontamination factors for Ca, Y, Ba and Cs were found to be adequate, and the role of other possible interferences is discussed. The Sr isolate was dissolved in scintillation cocktail prior to counting of 89Sr and 90Sr in a single measurement with a low-level liquid scintillation spectrometer. Scintillation spectra and counting efficiencies for 89Sr, 90Sr and 90Y have been established. A simple spectral stripping technique may thus be applied to calculate activities from the spectra of real samples. Results of analyses of five 2-1 milk samples containing known activities of 89Sr and 90Sr were respectively 87.7 +/- 3.5% and 90.4 +/- 3.0% (+/- 1 S.D.) of the activities added. A correction factor for the Sr yield was not applied. The detection limit of 0.014 Bq for 90Sr samples free of 89Sr implies that the method is also useful for routine monitoring of 90Sr.
本文介绍了一种方法，可在5至8小时的分析时间内，从2升生乳样品中以90.4%的回收率可重复地回收锶（Sr）。所有可能干扰89Sr和90Sr测量的物质均被有效去除；已发现钙、钇、钡和铯的去污系数足够，并讨论了其他可能干扰因素的作用。在使用低本底液体闪烁光谱仪进行单次测量以计数89Sr和90Sr之前，将分离出的Sr溶解在闪烁鸡尾酒中。已确定了89Sr、90Sr和90Y的闪烁光谱及计数效率。因此，可应用一种简单的光谱剥离技术，根据实际样品的光谱计算活度。对五个含有已知活度的89Sr和90Sr的2升牛奶样品的分析结果分别为添加活度的87.7±3.5%和90.4±3.0%（±1标准差）。未应用Sr回收率的校正因子。对于不含89Sr的90Sr样品，其检测限为0.014 Bq，这意味着该方法也可用于90Sr的常规监测。
