GerConsult, 44892 Bochum, Germany.
Hyla Environmental Consulting, LLC, Midland, MI 48640, USA.
Sci Total Environ. 2022 Dec 10;851(Pt 2):158275. doi: 10.1016/j.scitotenv.2022.158275. Epub 2022 Aug 26.
Monitoring studies that aim to quantify volatile methyl siloxanes (VMS) in environmental matrices may encounter a multitude of issues, most of which relate to the unique combination of physical-chemical characteristics of VMS that distinguish them from other classes of organic compounds. These properties, which are critical to their function in various applications, also control their fate and distribution in the environment, as well as the analytical chemistry of their measurement. Polycondensation and rearrangement reactions of VMS oligomers are possible during sample storage and analysis. Thus, care should be exercised to suppress these types of reactions by avoiding any catalytic substances or surfaces in sample collection and analysis equipment. Another factor complicating sample integrity in the analysis of trace levels of VMS, is their ubiquitous presence in many common products and components of instrumentation in the laboratory. For example, some gas chromatography columns and inlet septa have been identified as sources of VMS due to surface-catalyzed transformation of silicones to VMS promoted by moisture under high temperature in some silicone-based GC columns. Possible chemical transformation of the analytes, contamination from other sources, and potential loss of analytes need to be assessed throughout all aspects of the study, from sample collection through analysis, by establishing a rigorous quality assurance and quality control program. The implementation of such a robust QA/QC program facilitates the identification and minimization of potential analytical biases and ensures the validity and usability of data generated from environmental monitoring campaigns for VMS. The objective of this paper is to focus on aspects of collection, processing, and analysis of environmental samples that may influence the quality of the VMS analytical results. This information should then be employed in the design and implementation of future monitoring studies and can used to assess the validity of analytical results from VMS monitoring studies.
监测研究旨在量化环境基质中的挥发性甲基硅氧烷（VMS），但可能会遇到许多问题，其中大多数问题与 VMS 的独特物理化学特性有关，这些特性将其与其他有机化合物区分开来。这些特性对它们在各种应用中的功能至关重要，也控制着它们在环境中的命运和分布，以及它们的测量分析化学。VMS 低聚物在样品储存和分析过程中可能发生缩聚和重排反应。因此，在样品采集和分析设备中应避免使用任何催化物质或表面来抑制这些类型的反应。另一个使痕量 VMS 分析中样品完整性复杂化的因素是它们普遍存在于许多常见产品和实验室仪器组件中。例如，一些气相色谱柱和进样隔垫由于高温下硅胶基 GC 柱中水分促进的硅酮表面催化转化为 VMS，已被确定为 VMS 的来源。在整个研究过程中，从样品采集到分析，都需要评估分析物的可能化学转化、其他来源的污染以及分析物的潜在损失，通过建立严格的质量保证和质量控制计划来评估。实施这样一个强大的 QA/QC 计划有助于确定和最小化潜在的分析偏差，并确保从环境监测活动中生成的数据的有效性和可用性。本文的目的是重点关注可能影响 VMS 分析结果质量的环境样品采集、处理和分析的各个方面。这些信息可用于未来监测研究的设计和实施，并用于评估 VMS 监测研究的分析结果的有效性。
