背景:氯化石蜡(CPs)是由于其毒性而被归类为持久性有机污染物的工业化学品,坚持和倾向于远距离运输,生物累积和生物放大。尽管几十年来一直是环境关注的主题,CP的分析方法仍然难以达到足够的准确性。在对CP量化产生负面影响的问题中,缺乏完善的标准,作为纯物质和基质(认证)参考材料(CRM),发挥了重要作用。这项研究的重点是提供矩阵CRM作为质量控制工具,以提高CP测量结果的可比性。
结果:我们介绍了ERM®-CE100的认证过程,这是第一种具有短链和中链氯化石蜡质量分数认证值的鱼类参考材料(短链氯化石蜡和MCCP,分别)。认证是根据ISO17034:2016和ISO指南35:2017进行的,价值分配步骤是通过对具有CP分析能力的实验室进行比较,并根据不同的分析原理应用程序。在确认CRM的同质性和稳定性后,为短链氯化石蜡分配了两个认证值,取决于使用的校准物:31±9μgkg-1和23±7μgkg-1。MCCP认证值为44±17μgkg-1。所有指定的值都是相对于CRM中的湿重,该CRM是作为鱼酱生产的,以增强与常规生物群样品的相似性。
■鱼组织ERM-CE100是第一个商业上可用于分析CP的矩阵CRM,使分析实验室能够提高测量的准确性和计量可追溯性。认证的CP值基于气相和液相色谱以及各种质谱技术获得的结果,因此,为使用不同分析方法和设备的实验室提供了广泛的有效性。
BACKGROUND: Chlorinated paraffins (CPs) are industrial chemicals categorised as persistent organic pollutants because of their toxicity, persistency and tendency to long-range transport, bioaccumulation and biomagnification. Despite having been the subject of environmental attention for decades, analytical methods for CPs still struggle reaching a sufficient degree of accuracy. Among the issues negatively impacting the quantification of CPs, the unavailability of well-characterised standards, both as pure substances and as matrix (certified) reference materials (CRMs), has played a major role. The focus of this study was to provide a matrix CRM as quality control tool to improve the comparability of CPs measurement results.
RESULTS: We present the process of certification of ERM®-CE100, the first fish reference material assigned with certified values for the mass fraction of short-chain and medium-chain chlorinated paraffins (SCCPs and MCCPs, respectively). The certification was performed in accordance with ISO 17034:2016 and ISO Guide 35:2017, with the value assignment step carried out via an intercomparison of laboratories of demonstrated competence in CPs analysis and applying procedures based on different analytical principles. After confirmation of the homogeneity and stability of the CRM, two certified values were assigned for SCCPs, depending on the calibrants used: 31 ± 9 μg kg-1 and 23 ± 7 μg kg-1. The MCCPs certified value was established as 44 ± 17 μg kg-1. All assigned values are relative to wet weight in the CRM that was produced as a fish paste to enhance similarity to routine biota samples.
UNASSIGNED: The fish tissue ERM-CE100 is the first matrix CRM commercially available for the analysis of CPs, enabling analytical laboratories to improve the accuracy and the metrological traceability of their measurements. The certified CPs values are based on results obtained by both gas and liquid chromatography coupled with various mass spectrometric techniques, offering thus a broad validity to laboratories employing different analytical methods and equipment.