Iron measurement in water is important to ensure its quality. Although iron is essential for good health, when its level in water exceeds the permitted limit, it can cause health- and environmental-related issues. In this study, a spectroscopic methodology based on laser-induced breakdown spectroscopy (LIBS) has been developed for in situ detection and quantification of iron in water. Wastewater from the foundation of a historic building at the National Energy Technology Laboratory (NETL) Morgantown site was collected for ten continuous days and analyzed with the LIBS benchtop system and NETL’s LIBS probe. Spectral signatures of iron in the LIBS spectra were identified which demonstrated the significant presence of iron in the test samples. Chemometric tools, principal component analysis (PCA) and linear discriminant analysis (LDA) were used to distinguish the ten liquid samples. For quantitative study, univariate and multivariate analyses were performed. While two strong emission lines of iron, Fe I 371.9 nm and Fe I 373 nm, were used to develop the calibration curve for univariate analysis, whole spectra in the selected wavelength range were utilized to plot the partial least square regression (PLS-R) curve. These calibration curves were then used to estimate the iron content in water samples, and the estimated values were compared to inductively coupled plasma-mass spectrometry (ICP-MS) measurements. The relative difference was found to be less than 15%, which shows that the iron content in liquid can be reliably detected and quantified by the LIBS-based spectroscopic technique.

水中铁的测量对于确保其质量非常重要。尽管铁对于健康至关重要，但当水中的铁含量超过允许限度时，可能会导致健康和环境相关问题。在这项研究中，开发了一种基于激光诱导击穿光谱（LIBS）的光谱方法，用于原位检测和定量水中的铁。连续十天收集来自国家能源技术实验室 (NETL) 摩根敦基地历史建筑地基的废水，并使用 LIBS 台式系统和 NETL 的 LIBS 探头进行分析。鉴定了 LIBS 光谱中铁的光谱特征，这证明了测试样品中铁的显着存在。使用化学计量工具、主成分分析（PCA）和线性判别分析（LDA）来区分十种液体样品。对于定量研究，进行了单变量和多变量分析。虽然铁的两条强发射线 Fe I 371.9 nm 和 Fe I 373 nm 用于建立单变量分析的校准曲线，但利用选定波长范围内的整个光谱来绘制偏最小二乘回归 (PLS-R)曲线。然后使用这些校准曲线来估算水样中的铁含量，并将估算值与电感耦合等离子体质谱 (ICP-MS) 测量值进行比较。相对差异小于15%，这表明基于LIBS的光谱技术可以可靠地检测和定量液体中的铁含量。