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Reclaimed Wastewater Monitoring — Sampling and Analysis
Published in Donald R. Rowe, Isam Mohammed Abdel-Magid, Handbook of Wastewater Reclamation and Reuse, 2020
Donald R. Rowe, Isam Mohammed Abdel-Magid
The advantages of atomic absorption spectroscopy as compared to emission spectroscopy is that atomic absorption is quite specific for many elements. Absorption depends upon the presence of free unexcited atoms in the flame, and these are in much greater abundance than excited atoms. Elements such as lead, mercury, and zinc are not easily excited in the flame and give poor sensitivities with the flame photometer but are readily detected by atomic absorption procedures. Also, the atomic absorption method is less subject to interference from other elements present in the water sample.
Gaseous air pollutants
Published in Abhishek Tiwary, Ian Williams, Air Pollution, 2018
In AAS (Figure 2.18), the material for analysis is atomised at high temperature (either injected into an air–acetylene flame at 3000°C, or vaporised in a graphite furnace). A beam of radiation is passed through the vapour, so that photons knock electrons from a low (usually ground) energy state up to a higher state; hence photons are absorbed and the radiation flux is depleted. The radiation source is a hollow cathode lamp constructed from the element to be analysed, so that it emits narrow spectral lines appropriate to that element rather than a continuous spectrum. This greatly reduces the stray light transmission and increases the sensitivity. The total amount transmitted at different wavelengths is measured photoelectrically, and the absorbance is determined. From the Beer–Lambert law, It = I0 exp (−kL), where It, I0 are the transmitted and incident flux densities, k is the extinction coefficient and L is the optical path length. Also k = εC, where ε is a constant for the substance and wavelength, and C is the vapour concentration. Hence, C can be calculated. Atomic absorption spectroscopy is used almost exclusively for determinations of metallic elements.
Trace Metals and Ions
Published in Tadahiro Ohmi, Ultraclean Technology Handbook, 2017
Atomic absorption spectroscopy and inductive coupling plasma analysis (ICP) are ordinarily used for the analysis of heavy metals. There are two types of atomic absorption spectrocopy: flame atomic absorption spectroscopy utilizes an acetylene flame and air or dinitrogen monoxide for atomization, and flameless (furnace) atomic absorption spectroscopy conducts atomization in a graphite tube electric heating furnace [4,5]. Because the analysis of heavy metals in ultrapure water requires high sensitivity, flameless atomic absorption is often employed. The following sections describe this method.
Silicon alleviates arsenic-induced toxicity in wheat through vacuolar sequestration and ROS scavenging
Published in International Journal of Phytoremediation, 2018
Md Monayem Hossain, Most Amena Khatun, Md Najmul Haque, Md Azizul Bari, Md Firoz Alam, Abul Mandal, Ahmad Humayan Kabir
Roots and leaves were harvested from 5-day-old plants and were digested in 3 mL HNO3. The tissue samples were then heated in microwave oven at 75°C for 10 min, followed by 109°C for 15 min. The samples were then cooled for 10 min before adding 1 mL of perchloric acid and heated at 109°C for 15 min. Further, the samples were analyzed by flame atomic absorption spectroscopy (AAS) outfitted (AA-6800, Shimadzu). The standard solutions (As, Fe, and P) were separately prepared from their respective concentration from which further diluted for the standard calibration curve (Begum et al.2016).
Speciation analysis and dynamic absorption characteristics of heavy metals and deleterious element during growing period of Chinese peony
Published in International Journal of Phytoremediation, 2019
Guanjun Nan, Liying Guo, Yuqiong Gao, Xianxin Meng, Lina Zhang, Ning Song, Guangde Yang
Analyses were carried out by an Atomic Absorption Spectrophotometer with a hollow cathode lamp (AAS, Perkin-Elmer Model 5000; PerkinElmer Inc., Wellesley, MA, USA) coupled with a graphite furnace (GF) with a Zeeman background correction. Samples were injected into the GF system by an auto sampler Perkin-Elmer AS-40 (PerkinElmer Inc., Wellesley, MA, USA).