a National Reference Center for the Detection of Radioactivity in Feed and Foodstuff , Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata , Foggia , Italy.
Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2014;31(12):2014-21. doi: 10.1080/19440049.2014.968883. Epub 2014 Nov 14.
Strontium-90 is a hazardous radionuclide derived from nuclear fission processes, and it decays emitting high-energy beta-particles forming yttrium-90. It may be easily absorbed in humans through several food supply chains, since it is chemically similar to some important biological elements such as potassium and calcium. In this work an analytical method for the determination of radiostrontium in milk by liquid scintillation counting was developed in order to obtain a precise quantification at low activity concentration levels. Moreover, a full validative approach was applied to confirm method reliability. Good analytical performance was obtained by developing an in-house validation model according to Regulation 882/2004/EC and Decision 657/2002/EC with a good selectivity, a decision threshold and detection limit corresponding to 0.003 and 0.006 Bq l⁻¹ (α = β = 0.05) respectively, a repeatability value, expressed as CV%, equal to 13%, a mean recovery value equal to 102.5% and a measurement uncertainty equal to 11.5%. Strontium and yttrium chemical yields were determined by a reliable analytical method by inductively coupled mass spectrometry, assuring a suitable correction of final result. The results of the method validation, combined with a quality control assurance, performed on a reference material, demonstrated that the procedure represents a substantial improvement in the determination of ⁹⁰Sr relating to accurate confirmation analyses.
锶-90 是一种源自核裂变过程的危险放射性核素，它通过发射高能 β 粒子衰变为钇-90。由于其化学性质与钾和钙等一些重要的生物元素相似，因此很容易通过多种食物供应链被人类吸收。本工作开发了一种通过液体闪烁计数测定牛奶中放射性锶的分析方法，以便在低活度浓度水平下进行精确定量。此外，还应用了完整的验证方法来确认方法的可靠性。通过根据法规 882/2004/EC 和决定 657/2002/EC 开发内部验证模型，获得了良好的分析性能，该模型具有良好的选择性、决策阈值和检测限分别对应 0.003 和 0.006 Bq l⁻¹（α = β = 0.05）、重复性值（表示为 CV%）等于 13%、平均回收率值等于 102.5%和测量不确定度等于 11.5%。通过电感耦合质谱法确定了锶和钇的化学收率，确保了对最终结果的适当校正。方法验证的结果与质量控制保证相结合，对参考物质进行了测试，证明该程序在 ⁹⁰Sr 的测定方面有了实质性的改进，可用于准确的确认分析。
