Pierchala Anna, Rozanski Kazimierz, Dulinski Marek, Gorczyca Zbigniew, Marzec Michal, Czub Robert
a Faculty of Physics and Applied Computer Science , AGH University of Science and Technology , Krakow , Poland.
Isotopes Environ Health Stud. 2019 Jun;55(3):290-307. doi: 10.1080/10256016.2019.1609959. Epub 2019 Apr 30.
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 δH, δO and δO 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 δH, δO, δO, d-excess and ΔO, 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 δH, δO, δO, d-excess and ΔO). 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 δH analysis.
对测量不确定度进行全面评估，并控制测量的短期和长期精度，应是任何旨在维持高质量分析过程的成功质量保证/质量控制（QA/QC）策略的基础。在此，我们展示了对Picarro L2140-i CRDS激光光谱仪分析水中δH、δO和δO的分析性能进行全面评估的结果。该评估基于该仪器在15个月连续运行期间（2017年2月至2018年5月）获得的结果。对于δH、δO、δO、d-过量和ΔO，测量和导出量的短期精度分别为0.11、0.036、0.028、0.23‰和每百万分之11，与制造商报告的精度相当。L2140-i的长期精度定义为在15个月内对实验室标准进行的153次分析的时间序列的标准不确定度，大约低两倍（对于δH、δO、δO、d-过量和ΔO，分别为0.24、0.053、0.038、0.37‰和每百万分之21）。对单次分析的测量不确定度进行深入评估表明，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δH分析的情况下。
