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Methods for Analysis of Solid Samples
Published in Somenath Mitra, Pradyot Patnaik, Barbara B. Kebbekus, Environmental Chemical Analysis, 2018
Somenath Mitra, Pradyot Patnaik, Barbara B. Kebbekus
Which atomic spectroscopic method is chosen depends to some extent on the detection limits necessary. Atomic absorption (AA) spectroscopy, either flame or electrothermal, inductively coupled plasma emission spectroscopy (ICP), or inductively coupled plasma mass spectrometry (ICP-MS) are the methods most often used. Flame emission and atomic fluorescence are used less commonly. Cold vapor absorption is used for mercury determination, and hydride generation for metals such as arsenic and selenium, which are subject to serious interferences in flame AA. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) and ICP-MS are by far the most sensitive instruments, providing simultaneous multielement analysis. However, they are also more expensive. In some applications, graphite furnace atomization may be convenient because it may eliminate the need for sample preparation. For example, to determine lead levels in blood, a few microliters of sample can be injected directly into the graphite furnace.
Analytical Chemistry for Industrial Hygienists
Published in Martin B., S.Z., of Industrial Hygiene, 2018
Inductively coupled plasma-atomic emission spectroscopy (ICP-AES) is another analytical technique used for the determination of metals. This method is used when multi-element determinations are desired. The principle is the reverse of atomic absorption spectroscopy. Radiation is emitted at specific wavelengths by excited atoms corresponding to the energy released for an electronic transition from the excited state to ground state. With a focus on specific wavelengths, up to 30 elements can be measured in a single sample. ICP can be used in the sequential (one metal analyzed after another) or in the simultaneous (several metals analyzed simultaneously) detection mode. In this method, samples must also be solubilized. The instrument measures the characteristic emission spectra by optical spectroscopy. Samples are nebulized and the resulting aerosol is transported to the plasma torch produced by a radio frequency-induced coupled plasma with a temperature range of 5000 to 10,000°C. The emission spectra produced are element specific. The spectra are dispersed by a grating spectrometer, and the intensities of the emission lines are monitored by photosensitive devices. The radiation is in the ultraviolet, visible, and near infrared regions of the electromagnetic spectrum. Most applications of ICP operate in the 190–800 nm region.
Development of an Activity Transport Model and In Situ Measurements on Deposited Radionuclides in the Primary Coolant Pipelines of the Chinshan Nuclear Power Plant
Published in Nuclear Science and Engineering, 2023
Yu-Hung Shih, Mei-Ya Wang, Tsuey-Lin Tsai, Tsung-Kuang Yeh
There are three feedwater sampling ports at Chinshan-1, as indicated in Fig. 1, and the sampling system operating at 240°C uses stainless steels as the structural materials, the same as those in the coolant piping and components. The technology of integrated filtration with cellulose particulate filters of 47 mm in diameter and 0.45 μm in pore size is adopted. Insoluble corrosion products are generally collected from the 1000 to 2000 L of water that are drawn from the feedwater sampling ports. Prior to passing through the filters, the feedwater would be cooled down and depressurized. The scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) techniques are used for morphology and phase analyses on the corrosion products, respectively. The filtered samples are dried at 120°C and dissolved in an HNO3 and HCl (1:1) mixed solution. An elemental analysis is then performed with inductively coupled plasma-atomic emission spectroscopy (ICP-AES).