Abstract Due to the penetration of harmful chlorides into concrete, e.g. from de-icing salt, damage processes such as chloride-related pitting corrosion can occur if critical values are exceeded. In this study, multiphase materials such as chloride-contaminated concrete are examined in detail. A direct comparison is made by analyzing the spectroscopic information of simultaneously measured atomic and molecular emissions with laser-induced breakdown spectroscopy (LIBS). In addition, the influence on the calibration is examined on the basis of the combined spectral information of both reaction paths of the penetrated chlorides. The calibration models of univariate and multivariate methods were validated using reference samples with wet chemical analysis. The results are applied to a concrete sample of a parking deck, which was also analyzed by potentiometric wet chemistry. In order to account for the heterogeneity of concrete, spatially (200 μm) and spectroscopically (0.1 nm) resolved LIBS measurements were performed using a fully automated laboratory system. Simultaneous measurements with three spectrometers allow the analysis of the emission processes of several elements such as Cl, Ca, O, Si and Mg as well as the newly formed molecules CaO and CaCl. The evaluation of the molecular emission in combination with atomic lines extends the analytical performance, since different concrete phases such as aggregates and cement matrix can be better represented. The measurements were carried out in ambient air and with helium purge gas. The limit of detection (LOD) achieved for a combined evaluation of atomic and molecular emission was determined to be 0.028 wt%.

中文翻译：

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LIBS 中原子和分子发射的比较，用于量化水泥基材料中的有害物质

摘要 由于有害氯化物渗透到混凝土中，例如来自除冰盐，如果超过临界值，就会发生破坏过程，例如与氯化物相关的点蚀。在这项研究中，详细检查了多相材料，如氯化物污染的混凝土。通过使用激光诱导击穿光谱 (LIBS) 分析同时测量的原子和分子发射的光谱信息，进行直接比较。此外，根据渗透氯化物的两个反应路径的组合光谱信息，检查对校准的影响。使用湿化学分析的参考样品验证单变量和多变量方法的校准模型。结果应用于停车甲板的混凝土样本，这也通过电位湿化学分析。为了解释混凝土的异质性，使用全自动实验室系统进行空间 (200 μm) 和光谱 (0.1 nm) 分辨 LIBS 测量。使用三个光谱仪同时测量可以分析多种元素的发射过程，例如 Cl、Ca、O、Si 和 Mg 以及新形成的分子 CaO 和 CaCl。结合原子线对分子发射的评估扩展了分析性能，因为可以更好地表示不同的混凝土相，例如骨料和水泥基体。测量是在环境空气和氦气吹扫气体中进行的。对原子和分子发射的综合评估所达到的检测限 (LOD) 确定为 0.028 wt%。