Sensitive analysis of fluorine and chlorine elements in water solution using laser-induced breakdown spectroscopy assisted with molecular synthesis

• Published in: Talanta (Oxford) 2021-03, Vol.224, p.121784-121784, Article 121784
• Main Authors: Tang, Zhiyang, Hao, Zhongqi, Zhou, Ran, Li, Qingzhou, Liu, Kun, Zhang, Wen, Yan, Jiujiang, Wei, Kaiwen, Li, Xiangyou
• Format: Article
• Language: English
• Subjects: Chlorine; Fluorine; LIBS; Molecular systhesis
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2020.121784

Fluorine and chlorine are key elements to affecting water quality, but they are hard to be determined by conventional laser-induced breakdown spectroscopy (LIBS). To achieve high sensitivity detection of them, the CaF and CaCl molecules were synthesized by combining calcium in calcite and F and Cl in sample. The temporal characteristics of CaF and CaCl molecular emissions were investigated. It shows that molecular emission of CaF and CaCl has a longer lifetime and high spectral intensity than that of their atomic emissions. Such unique feature of molecular emission inspired us to use it for high sensitivity analysis of Cl and F elements in water. The results show that these two elements can be sensitively and accurately detected using LIBS assisted with molecular emission. The limits of detections (LoDs) were 0.38 mg/L and 1.03 mg/L for F and Cl elements, respectively, and the limit of quantitation (LoQ) was 3.404 mg/L to 20.569 mg/L for fluorine elements and 9.986 mg/L to 39.757 mg/L for fluorine. These detection limits can meet the World Health Organization's detection requirements for F and Cl elements in water. The results show that LIBS assisted with molecular synthesis has a huge potential in water quality monitoring. [Display omitted] •LIBS assisted with Molecular Synthesis was proposed to sensitively and accurately detect F and Cl in water.•CaF and CaCl molecule was selected to replace the F and Cl atom indirectly analyze F and Cl in water, respectively.•The characteristics of CaF and CaCl molecule with time-resolved emission spectroscopy was investigated.•The analytical performances of F and Cl in water could be evidently improved using LIBS assisted with Molecular Synthesis.•Highly accurate and sensitive determination of fluorine and chlorine elements in water solution was achieved by our method.