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Chemical Analysis in Environmental and Toxicological Chemistry
Published in Stanley E. Manahan, Environmental Chemistry, 2022
Analytical chemistry is that branch of the chemical sciences employed to determine the composition of a sample of material. A qualitative analysis is performed to determine what is in a sample. The amount, concentration, composition, or percentage of a substance present is determined by quantitative analysis. Often, both qualitative and quantitative analyses are performed as part of the same process.
Comprehensive Array of Ample Analytical Strategies for Characterization of Nanomaterials
Published in Vineet Kumar, Praveen Guleria, Nandita Dasgupta, Shivendu Ranjan, Functionalized Nanomaterials I, 2020
Nitesh Dhiman, Amrita Singh, Aditya K. Kar, Mahaveer P. Purohit, Satyakam Patnaik
Spectroscopy was originally the study of the how electromagnetic waves interact and behave with matter as a function of wavelength (λ). Spectroscopy/spectrometry is often used in physical and analytical chemistry for analyzing the materials and liquids by the amount of light emitted from, absorbed, or scattered by them. When an appropriate wavelength of light hits a sample, the energy of the radiation is absorbed by the ground-state electrons that are excited and jump to upper energy orbitals. This phenomenon is called absorption, and electrons in the upper unstable energy state often tend to come down to the ground level. Upon returning to their ground state, electrons lose their extra energy through emission by adopting several paths, which explains phenomena such as fluorescence, luminescence, and phosphorescence. The various spectroscopic techniques are discussed below.
Chemical Analysis in Environmental and Toxicological Chemistry
Published in Stanley Manahan, Environmental Chemistry, 2017
Analytical chemistry is that branch of the chemical sciences employed to determine the composition of a sample of material. A qualitative analysis is performed to determine what is in a sample. The amount, concentration, composition, or percentage of a substance present is determined by quantitative analysis. Often, both qualitative and quantitative analyses are performed as part of the same process.
Survey on algebraic numerical differentiation: historical developments, parametrization, examples, and applications
Published in International Journal of Systems Science, 2022
Amine Othmane, Lothar Kiltz, Joachim Rudolph
Many approaches have been proposed over the years. In the signal processing literature, the problem has been tackled using frequency-domain digital filter design techniques as in Chen and Lee (1995), Rader and Jackson (2006). Applied and pure mathematicians have discussed several different approximation formulas using integrals involving orthogonal polynomials. Early works are Cioranescu (1934), Lanczos (1956). A recent survey summarising the history of approximation formulas for higher-order derivatives by integrals involving orthogonal polynomials can be found in Diekema and Koornwinder (2012). Mollification and Tikhonov regularisation methods have been proposed in Murio (2011) and Cullum (1971), respectively. In analytical chemistry and spectroscopy, the discrete Savitzky-Golay filters introduced in Madden (1978), Savitzky and Golay (1964) have been popular. The control community has developed approaches based on observer design as in Chitour (2002), Dabroom and Khalil (1997, 1999), Levant (1998, 2003) and differential-algebraic methods, which are of interest in the current work.
Moment propagation method for the dynamics of charged adsorbing/desorbing species at solid-liquid interfaces
Published in Molecular Physics, 2018
Adelchi Asta, Maximilien Levesque, Benjamin Rotenberg
Even without electrokinetic couplings, specific effects play an important role on the dynamics of charged species. For example, the diffusion of ions in porous materials depends not only on their charge but also on their chemical nature. An illustration can be found, e.g. with the different properties of Na+ and Cs+ tracers in clays, which go beyond their different behaviour in the bulk [20]. Of course, charged tracers also experience the effects of hydrodynamics and electrokinetic couplings in the fluid as a whole, in addition to their own dynamics and interactions with the solid surfaces. This is exploited in practice in analytical chemistry, e.g. in chromatography or electrophoresis experiments [21]. It is well known, e.g. in the chemical engineering community that even in the case of uncharged solids and solutes, the coupling between pore-scale motion and surface adsorption may result in intricate macroscopic transport properties [22]. Surface charge and charged solutes only increase the difficulty to understand and predict the emerging behaviour.
Compact instrumentation and (analytical) performance evaluation for laser-induced breakdown spectroscopy
Published in Instrumentation Science & Technology, 2019
Guangmeng Guo, Guanghui Niu, Qingyu Lin, Shuai Wang, Di Tian, Yixiang Duan
Calibration curve is one of the most universal evaluation methods for quantitative analysis in analytical chemistry. As mentioned above, the quantitative capability of the instrument was accessed by using a set of certified copper mineral samples with four selected lines, Cu (I) 510.55 nm, Cu (I) 521.82 nm, Zn (I) 307.58 nm, and Zn (I) 328.23 nm, which were well separated with other lines. The constructed calibration curves all presented good linear performance with the correlation coefficient R2 values of 0.97432, 0.9826, 0.97286, and 0.98176 for Cu (I) 510.55 nm, Cu (I) 521.82 nm, Zn (I) 307.58 nm, and Zn (I) 328.23 nm, respectively. The error bars were obtained under 30 individual measurements.