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Интеллектуальная Система Тематического Исследования НАукометрических данных |
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Multivariate calibration for chlorine determination in concrete by Laser-induced breakdown spectroscopy of CaCl moleculeтезисы доклада
- Авторы: Labutin T.A., Zakuskin A.S., Popov A.M., Zaytsev S.M.
- Сборник: Eleventh Winter Symposium on Chemometrics, Modern Methods of Data Analysis, February 26-March 2, 2018
- Тезисы
- Год издания: 2018
- Место издания: Russia, Saint Petersburg
- Первая страница: 67
- Последняя страница: 69
- Аннотация: Concrete degradation is still a serious problem in the construction industry. Interaction with an atmosphere, water, or ground can modify the chemical composition of concrete reinforced structures. The main forms of chemical attack on concrete reinforced structures are chloride corrosion of steel reinforcement, carbonation, and sulfate attack. It was shown that laser-induced breakdown spectroscopy (LIBS) can be used for the elemental analysis of building structures. The main advantages of LIBS for diagnostics of building materials are: relatively simple apparatus, which allows miniaturization and automation of the analytical measurements in the field; high throughput and local analysis. At the same time known techniques of determination of chlorine and sulfur by LIBS, which provide needed level of sensitivity, can be hardly realized in portable arrangement for field measurements. Thus, it is still important the development of approaches, which can help in miniaturization of instrument with appropriate sensitivity of non-metals determination in concrete. The use of emission of diatomic molecules instead of atomic lines to determine hardly excited species like halogens is well-known approach in atomic emission spectroscopy. The advantages of the molecular bands are related to a sufficiently high excitation potential chlorine line (~ 10.5 eV), and a low degree of its atomization in plume. The molecular bands of MgCl, CaCl and AlCl were evaluated for chlorine detection. We have also applied double-pulse LIBS to use the atomic lines Cl I 833.7 nm for the comparison. It was found that only the orange system of CaCl molecule was sufficiently intense for chlorine determination in concrete by common LIBS at the late times of plasma existence (30 µs after laser pulse). The analytical signal has depended linearly on chlorine content in concrete. However, the complex structure of the vibrational levels of the orange system results in the spectrum with a wide asymmetric band accomplished by numerous interferences from the atomic lines. This has prevented determination of low chlorine content, which is important to reveal the dangerous level of chlorine accumulation in concrete. In such a situation, the most appropriate and simple solution is the use of multivariate calibrations to provide accurate analysis. We have prepared 20 samples simulating the concrete samples with different chlorine contents. The application of PCR provided a calibration model appropriate for reliable chlorine determination at the threshold level. Thus the multivariate calibration with the use of CaCl emission measured with the common LIBS setup as analytical signal improved the sensitivity.
- Добавил в систему: Лабутин Тимур Александрович