Analytical techniques solid waste

A number of less commonly used analytical techniques are available for determining PAHs. These include synchronous luminescence spectroscopy (SLS), resonant (R)/nonresonant (NR)-synchronous scan luminescence (SSL) spectrometry, room temperature phosphorescence (RTP), ultraviolet-resonance Raman spectroscopy (UV-RRS), x-ray excited optical luminescence spectroscopy (XEOL), laser-induced molecular fluorescence (LIMP), supersonic jet/laser induced fluorescence (SSJ/LIF), low- temperature fluorescence spectroscopy (LTFS), high-resolution low-temperature spectrofluorometry, low-temperature molecular luminescence spectrometry (LT-MLS), and supersonic jet spectroscopy/capillary supercritical fluid chromatography (SJS/SFC) Asher 1984 Garrigues and Ewald 1987 Goates et al. 1989 Jones et al. 1988 Lai et al. 1990 Lamotte et al. 1985 Lin et al. 1991 Popl et al. 1975 Richardson and Ando 1977 Saber et al. 1991 Vo-Dinh et al. 1984 Vo- Dinh and Abbott 1984 Vo-Dinh 1981 Woo et al. 1980). More recent methods for the determination of PAHs in environmental samples include GC-MS with stable isotope dilution calibration (Bushby et al. 1993), capillary electrophoresis with UV-laser excited fluorescence detection (Nie et al. 1993), and laser desorption laser photoionization time-of-flight mass spectrometry of direct determination of PAH in solid waste matrices (Dale et al. 1993). 

Environmental problems (air, water, solid waste, and occupational health and safety) and their control receive a great deal of interest and publicity. We have come to realize that this is a very complex area and while many advances have been made, much is yet to be learned concerning the environment. Analytical chemistry plays a very important role in both defining and controlling environmental pollution. In this chapter, we briefly describe some of the analytical techniques used to collect and analyze environmental samples. 

Solid samples, such as soils and solid wastes which are quite insoluble in solvents, have to be submitted to an analyte extraction process. In some cases, such as in elemental analysis, it is adequate to digest the sample in a strong acid. However, in other cases, the analyte may be destroyed under strongly acidic conditions and alternative extraction methods have to be used. The most important and internationally used techniques are discussed in the following sections. 

Nuclear analytical techniques (NATs) and related isotopic tracer methods are well established as important tools in a wide variety of different kinds of environmental studies. They provide a wealth of information on sources, pathways and effects of many elements of environmental and health-related interest. Apart from being regarded as of particular strength in analytical quality assurance (IAEA, 1997), nuclear and related techniques cover studies of air particulates, solid waste products, sediments, food, water, human tissues, biomonitors and other kinds of environmental samples. 

The present section provides an outline of the environmental forensic approach, the different types of possible contaminants released from solid wastes (disposed in landfills or recycled as road construction and repair materials), and analytical techniques and advances in contaminant identification and characterization. 

There is often a need to monitor cyanide in air, water, solid waste, food, and other environmental samples. The cyanide present in these samples may include free (noncomplexed) cyanide such as hydrogen cyanide (or hydrocyanic acid in water solution), cyanogen (C2N2), cyanogen chloride, cyanide salts, or complexed cyanide such as metal-cyanide complexes of iron, nickel, copper, mercury, silver. Complexed cyanides are less toxic because they are less bioavail-able, but they may break down producing free cyanide, for example, as a result of the ultraviolet radiation in daylight. Analytical techniques for free... 

Thermoplastics processing operations produce emissions into the air, wastewater, and solid waste resulting from both polymers and additives. Most important are volatile organic compounds emitted from heated cylinders and molds. The identification of such volatiles and the development of analytical techniques for measuring their concentration in the workplace are of paramount importance to establish or revise threshold limit values that would minimize exposure to hazardous chemical substances. Environmental issues in polymer processing are reviewed in References 18 and 19. 

Chapter 24 covers resources, bolli renewable and nonrenewable, as well as energy from fossil and renewable sources. The last two chapters outline analytical chemistry. Chapter 25 presents the major concepts and techniques of analytical chemistry. Chapter 26 discusses specific aspects of envirorunental chemical analysis, including water, air, and solid-waste analysis, as well as the analysis of xenobiotic species in biological systems. 

Conventional radiochemical methods for the determination of long-lived radionuclides at low concentration levels require a careful chemical separation of the analyte, e.g., by liquid-liquid, solid phase extraction or ion chromatography. The chemical separation of the interferents from the long-lived radionuclide at the ultratrace level and its enrichment in order to achieve low detection limits is often very time consuming. Inorganic mass spectrometry is especially advantageous in comparison to radioanalytical techniques for the characterization of radionuclides with long half-lives (> 104 a) at the ultratrace level and very low radioactive environmental or waste samples. 

The other form of on-line solid-phase extraction procedures involves column-switching techniques. Column switching employs valves that can be switched manually or automatically between a number of columns at predetermined times.67-69 For sample cleanup the analyte of interest is retained on the primary or precolumn while the interfering matrix components are eluted to waste. The analytes are then diverted to a second or analytical column where they are separated for identification and quantification. 

Steroid hormones are found as pollutants in drinking water, waste water, river and sediments. The major concerns of analytical methodologies for monitoring steroid hormones from environmental samples are extraction techniques from aqueous or solid matrices. Since sample volume or amount is not an issue in most cases, SPE is the method of choice. Both LC-MS/MS and GC-MS technologies are broadly applied for steroid analyses of environmental samples, such as LC-MS/MS analyses of steroid hormones in effluents of wastewater treatment plants [100] and estrogens in water [101,102], and GC-MS analyses of steroid hormones in environmental water [34,45, 78, 79], A study by Grover and colleagues showed that GC-MS was the simplest technique in determination of steroid hormones in environmental water samples, but lack of sensitivity LC-MS/MS was more sensitive than GC-MS, but susceptible to matrix interferences and GC-MS/MS was the recommended technique, because it was more selective and sensitive than GC/MS and LC-MS/MS [103],... 

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