Grahek Željko, Dulanská Silvia, Karanović Gorana, Coha Ivana, Tucaković Ivana, Nodilo Marijana, Mátel Ľubomír
Laboratory for Radioecology, Ruđer Bošković Institute, Bijenička c. 54, 10 000 Zagreb, Croatia.
Department of Nuclear Chemistry, Faculty of Natural Sciences, Comenius University, Mlynska Dolina, Ilkovičova 6, 842 15 Bratislava, Slovakia.
J Environ Radioact. 2018 Jan;181:18-31. doi: 10.1016/j.jenvrad.2017.10.012. Epub 2017 Oct 31.
The paper describes different isolation/separation and detection procedures for Sr determination in the environmental samples which are routinely used in Laboratories A and B. In this context, four different methods for strontium isolation and two methods for detection were tested and compared by Sr determination in proficiency test samples (water, soil, vegetation) and animal bone samples. The chromatographic isolation of Sr on Sr resin, AnaLigSr01 resin gel, strong base anion exchange resins in nitrate form and combination of strong base anion exchange and Sr resin were used for the examination of the impact of sample matrix constituents on efficiency of strontium isolation (chemical yield), while Cherenkov counting of Y and counting of Sr(Y) on proportional counter were used for the quantitative Sr determination. The chemical yields obtained with different isolation methods were compared with the emphasis on its influence on reliability of the Sr determination in different kinds of samples. The results show that the efficiency of strontium isolation depends on type of sample and separation methodology. The strontium yield on Sr resin column decreases with the increase of Sr, Ca and Na concentration. In the presence of 1 g of Ca and 1 g of Na, the yield of 85% was obtained for 5 mg of Sr carrier and dropped below 50% with further increase of Sr and other elements. However, the yield can be increased to 75% if Na and part of Ca are separated from Sr on the anion exchange column with alcoholic solution of nitric acid and by final separation of Ca from Sr on the Sr resin column. In the presence of large amounts of Ca, Na and other elements, isolation efficiency on the Sr resin column significantly decreases in comparison with other methods. The average yield for isolation from vegetation samples on the Sr resin column is only 21%. For the soil samples the highest average yield (78%) is obtained for the isolation in the combination of anion exchange and Sr resin columns. For the isolation from bone samples the average yields over 80% are on AnaLigSr01 and anion exchange resins columns, while Sr resin was not used for separation due to high content of Ca in samples. The results of the Sr determination in proficiency testing (PT) samples show that the accuracy of the determination does not depend on high chemical yield but depends on accuracy of yield determination. The analysis of z-values shows that 96% of obtained z-values range from 0 to ±2 while 77% of z-values range between 0 and ± 1. Ninety percent of obtained results of Sr determination deviate less than 20% from assigned values in PT provider reports. The results of Sr determination in animal bone samples using different methods are in good agreement. The results obtained by Cherenkov counting in both laboratories vary from -3.1-14.5% while results obtained by determination via Y and counting on i-Matic vary between -10.0 and -2.9%. These deviations are in accordance with deviations obtained with PT samples. Activity concentrations of Sr in wild boar bone samples range from 4 to 30 Bq kg while in deer bone samples from 2 to 8 Bq kg.
本文描述了实验室A和B常规用于环境样品中锶测定的不同分离/提纯及检测程序。在此背景下，通过对能力验证样品（水、土壤、植被）和动物骨样品中的锶进行测定，测试并比较了四种不同的锶分离方法和两种检测方法。使用锶树脂、AnaLigSr01树脂凝胶、硝酸根形式的强碱性阴离子交换树脂以及强碱性阴离子交换树脂与锶树脂的组合对锶进行色谱分离，以研究样品基质成分对锶分离效率（化学产率）的影响，同时使用Y的切伦科夫计数法和在正比计数器上对Sr(Y)进行计数来进行锶的定量测定。比较了不同分离方法获得的化学产率，并重点关注其对不同类型样品中锶测定可靠性的影响。结果表明，锶的分离效率取决于样品类型和分离方法。锶树脂柱上的锶产率随Sr、Ca和Na浓度的增加而降低。在存在1 g Ca和1 g Na的情况下，5 mg Sr载体的产率为85%，随着Sr和其他元素的进一步增加，产率降至50%以下。然而，如果用硝酸酒精溶液在阴离子交换柱上从Sr中分离出Na和部分Ca，并最终在锶树脂柱上从Sr中分离出Ca，则产率可提高到75%。在存在大量Ca、Na和其他元素的情况下，与其他方法相比，锶树脂柱上的分离效率显著降低。在锶树脂柱上从植被样品中分离的平均产率仅为21%。对于土壤样品，在阴离子交换树脂柱和锶树脂柱组合分离时获得最高平均产率（78%）。对于从骨样品中分离，AnaLigSr01树脂柱和阴离子交换树脂柱的平均产率超过80%，而由于样品中Ca含量高，未使用锶树脂进行分离。能力验证（PT）样品中锶测定的结果表明，测定的准确性不取决于高化学产率，而是取决于产率测定的准确性。z值分析表明，96%的获得的z值范围为0至±2，而77%的z值范围在0至±l之间。90%的锶测定结果与PT提供者报告中的指定值偏差小于20%。使用不同方法对动物骨样品中锶的测定结果吻合良好。两个实验室通过切伦科夫计数获得的结果在-3.1%至14.5%之间变化，而通过Y测定和在i-Matic上计数获得的结果在-10.0%至-2.9%之间变化。这些偏差与PT样品获得的偏差一致。野猪骨样品中锶的活度浓度范围为4至30 Bq/kg，而鹿骨样品中为2至8 Bq/kg。
