Centro di Referenza Nazionale per la Ricerca della Radioattività nel Settore Zootecnico-Veterinario, Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata, Via Manfredonia 20, I-71121 Foggia, Italy.
Food Chem. 2012 Nov 15;135(2):319-24. doi: 10.1016/j.foodchem.2012.04.116. Epub 2012 May 2.
This study shows an exhaustive comparison of different methods, based on luminescence techniques, to identify X-ray irradiated oysters at five different dose levels in the range 0.1-2 kGy and suggests a simple, fast and sequential routine analysis protocol. A total number of 50 oysters from North Sea, including 10 control samples, were analysed by using two photo-stimulated luminescence (PSL) methods (named A and B) and three thermoluminescence (TL) methods (named C, D and E), either on constituents or contaminating minerals from shells and intestines. Setting a lower threshold value T1 (1000 counts/60s) all of control specimens gave negative screening results while photo counts from irradiated samples were found to be higher than upper threshold T2 (4000 counts/60s), except at the lowest dose level 0.1 kGy for procedure A. All PSL calibrated analysis were successful and a sensitivity index was also determined to better classify obtained data according to the revised European Standard (EN 13751:2009). TL ratios, Glow 1 over second Glow 2, the latter after irradiating at 1 kGy and remeasuring the same minerals for each sample, showed values less than 0.1 related to untreated samples or higher than 0.1 for irradiated ones. Reported procedures were also tested over 60 days, longer than oyster shelf life confirming the applicability and feasibility of the proposed methods.
本研究通过基于发光技术的方法，对不同方法进行了详尽的比较，以鉴别在 0.1-2kGy 范围内的五个不同剂量水平的辐照牡蛎，同时提出了一种简单、快速和连续的常规分析方案。共对来自北海的 50 个牡蛎（包括 10 个对照样本）进行了分析，使用两种光激励发光（PSL）方法（命名为 A 和 B）和三种热释光（TL）方法（命名为 C、D 和 E），分别对壳和肠中的成分或污染矿物质进行了分析。将较低的阈值 T1（1000 个计数/60 秒）设置为所有对照样本均给出阴性筛选结果，而辐照样本的光计数则高于上限 T2（4000 个计数/60 秒），除了程序 A 在最低剂量水平 0.1kGy 之外。所有经过 PSL 校准的分析均成功进行，还确定了一个灵敏度指数，以便根据修订后的欧洲标准（EN 13751：2009）更好地对获得的数据进行分类。TL 比值，Glow 1 与 Glow 2 的比值（后者在 1kGy 下辐照后，对每个样本的相同矿物质进行重新测量），显示出与未处理样本相关的小于 0.1 或大于辐照样本的 0.1 的值。所报道的程序也经过了 60 天以上的测试，超过了牡蛎的货架期，证实了所提出方法的适用性和可行性。
