Certain aspects in the collection, handling, storage, and subsequent analysis of discrete air samples from non-steady-state flux chambers are critical to generating accurate and unbiased estimates of nitrous oxide (N2 O) fluxes. The focus of this paper is on air sample collection and storage in small vials (<12 ml) primarily for gas chromatography (GC) analysis. Sample integrity is assured through following simple procedures including storage under pressure and analysis within a few months of collection. Concurrent storage of standards in an identical manner to samples is recommended and allows the storage period to be reliably extended. In the laboratory, an autosampler is typically used in batch analysis of ∼200 sequentially analyzed samples by GC with an electron capture detector (ECD). Some comparisons are given between GC and alternatives including optical N2 O detectors that are increasingly being used for high-precision N2 O measurement. The importance of calibration and traceability of gas standards is discussed, where high-quality standards ensure the most accurate assessment of N2 O concentration and comparability between laboratories. The calibration allows a consistent and best estimate of flux to be derived.

中文翻译：

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全球研究联盟 N 2 O 室方法指南：关于空气样本收集、存储和分析的建议

非稳态通量室离散空气样本的收集、处理、存储和后续分析的某些方面对于生成一氧化二氮 (N2 O) 通量的准确和无偏估计至关重要。本文的重点是在主要用于气相色谱 (GC) 分析的小瓶 (<12 ml) 中收集和储存空气样品。通过遵循简单的程序，包括在压力下储存和在收集后的几个月内进行分析，可以确保样品的完整性。建议以与样品相同的方式同时储存标准品，并允许可靠地延长储存期。在实验室中，自动进样器通常用于通过带有电子捕获检测器 (ECD) 的 GC 对大约 200 个顺序分析的样品进行批量分析。对 GC 和替代方案进行了一些比较，包括越来越多地用于高精度 N2 O 测量的光学 N2 O 检测器。讨论了气体标准品校准和可追溯性的重要性，其中高质量标准品可确保最准确地评估 N2 O 浓度和实验室之间的可比性。校准允许导出一致且最佳的通量估计。