ABSTRACT A thorough evaluation of measurement uncertainty together with control of short-term and long-term precision of measurements should be a basis of any successful quality assurance/quality control (QA/QC) strategy aimed at maintaining a high quality of the analytical process. Here we present the results of a comprehensive assessment of the analytical performance of a Picarro L2140-i CRDS laser spectrometer analysing δ2H, δ18O and δ17O in water. The assessment is based on results obtained during 15 months of continuous operation of this instrument (February 2017 to May 2018). The short-term precision of measured and derived quantities was 0.11, 0.036, 0.028, 0.23 ‰ and 11 per meg, for δ2H, δ18O, δ17O, d-excess and Δ17O, respectively, and is comparable to the precision reported by the manufacturer. The long-term precision of the L2140-i, defined as standard uncertainty of the time series of 153 analyses of a laboratory standard conducted throughout 15 months, was roughly two times lower (0.24, 0.053, 0.038, 0.37 ‰ and 21 per meg, for δ2H, δ18O, δ17O, d-excess and Δ17O). In-depth assessment of the measurement uncertainty of a single analysis revealed that assigned uncertainty of the calibration standards is an important component of the uncertainty budget, especially in case of δ2H analysis.

中文翻译：

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借助腔衰荡激光光谱仪高精度测量水中的 δ2H、δ18O 和 δ17O

摘要 对测量不确定度的彻底评估以及对测量的短期和长期精度的控制应该是任何旨在保持分析过程高质量的成功质量保证/质量控制 (QA/QC) 策略的基础。在这里，我们展示了对 Picarro L2140-i CRDS 激光光谱仪分析水中 δ2H、δ18O 和 δ17O 的分析性能的综合评估结果。该评估基于该仪器连续运行 15 个月（2017 年 2 月至 2018 年 5 月）期间获得的结果。δ2H、δ18O、δ17O、d-excess 和 Δ17O 的测量和导出量的短期精度分别为 0.11、0.036、0.028、0.23 ‰ 和 11 per meg，与制造商报告的精度相当。L2140-i 的长期精度，定义为在整个 15 个月内对实验室标准进行 153 次分析的时间序列的标准不确定度大约低两倍（0.24、0.053、0.038、0.37 ‰ 和 21 per meg，对于 δ2H、δ18O、δ17O、d-excess 和Δ17O)。对单个分析的测量不确定度的深入评估表明，校准标准的指定不确定度是不确定度预算的重要组成部分，尤其是在 δ2H 分析的情况下。