Specific groupings

A frequently requested analytical suite is for BTEX - benzene, toluene, ethylbenzene and xylenes. This restricted suite of VOCs is widely used as an 

Environment Agency (UK) (1988) Methods for the examination of waters and associated materials -The determination of volatile organic compounds in waters and complex matrices by purge and trap or by headspace techniques. 

ISO 10381-1 (1994) Soil quality - Sampling - Part 1 Guidance on the design of sampling programmes. 

ISO 10381-2 (1994) Soil quality - Sampling - Part 2 Guidance on the design of sampling techniques. ISO 10381 (1997) Water quality - Determination of highly volatile halogenated hydrocarbons - Gas-chromatographic methods. 

ISO 11465 (1993) Soil quality - Determination of dry matter and water content on a mass basis. 

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It must be emphasised that the above Tables must be used with caution. The presence of a specific group cannot always be established with certainty from the presence of the absorption band, particularly in the deformation vibration region on the other hand, the absence of the appropriate absorption band indicates that the grouping is not present. The physical state in which the substance is examined may have an appreciable influence the Tables apply generally to dilute solutions in organic solvents (see Table I). 

Alkyl, aryl, alkoxy and halogen subsituted silanes are referred to by prefixing silane by the specific group present. The following are typical examples ... 

Heavy metal A general term relating to a specific group of metals, which as suspended and deposited particulates can contaminate the environment. 

The tenth volume of this serial publication comprises six chapters, four of which deal with the general chemistry of a specific group of heterocyclic compounds pyridopyrimidines (W. J. Irwin and D. G. VVibberley), benzofuroxans (A. J. Boulton and P. B. Ghosh), isoindoles (J. D. White and M. E. Mann), and pyrylium salts (A. T. Balaban, W. Schroth, and G. Fischer). The remaining chapters are concerned with indole Grignard reagents (R. A. Heacock and S. Kasparek) and with cyclic hydroxamic acids (J. B. Bapat, D. St. C. Black, and R. C. Brown).The international flavor of the publication is preserved our contributors come from six countries in three continents. 

The third volume of this series covers three specific groups of compounds the carbolines (reviewed by R. A. Abramovitch and I. D. Spenser), the thiatriazoles (K. A. Jensen and C. Pedersen), and the pentazoles (I. Ugi). The remaining four chapters deal with topics of general chemical interest from the heterocyclic viewpoint the quaternization of heterocyclics (G. F. Duffin), carbene reactions (C. W. Rees and C. E. Smithen), applications of the Hammett equation (H. H. Jaffe and H. Lloyd Jones), and some aspects of the nucleophilic substitution of heterocyclic azines (G. Rluminati). 

FPN No. 2) The explosion characteristics of air mixtures of gases or vapors vary with the specific material involved. For Class I locations. Groups A, B, C, and D, the classification involves determinations of maximum explosion pressure and maximum safe clearance between parts of a clamped joint in an enclosure. It is necessary, therefore, that equipment be approved not only for class but also for the specific group of the gas or vapor that will be present. 

Like broadband analysis, narrowband analysis also monitors the overall energy, but for a user-selected band of frequency components. The ability to select specific groups of frequencies, or narrowbands, increases the usefulness of the data. Using this technique can drastically reduce the manpower required to monitor machine-trains and improve the accuracy of detecting incipient problems. 

There is a wide variation in properties among the over 35,0000 commercially available materials classified as plastics. They now represent an important, highly versatile group of commodity and engineering plastics. Like steel, wood, and other materials, specific groups of plastics can be characterized as having certain properties. As with other materi-... 

In this chapter the sections are arranged in accordance with the nomenclature of substitution transformations introduced by IUPAC (1989 c). In some sections homolytic and heterolytic dediazoniations are discussed together, provided that the diazo-nio group can be replaced by a specific group or class of groups homolytically as well as heterolytically. 

The substituents bound to Al and the group 15 element E generally adopt a staggered conformation relative to one another. The Al—N bond distances, which range from 197.2(4) 63 to 198.8(3) pm 60, are almost equal, indicating no significant electronic influence of the specific group 15 element on the... 

Cohort Study—A type of epidemiological study of a specific group or groups of people who have had a common insult (e.g., exposure to an agent suspected of causing disease or a common disease) and are followed forward from exposure to outcome. At least one exposed group is compared to one unexposed group. 

Allergy mediated by selective IgE to certain types of NSAIDs by which symptoms are caused exclusively by a specific group of NSAIDs and no cross-reactivity exists with the other groups of anti-inflammatories. In a study carried out with 26 methimazole-allergic patients with IgE-mediated reactions [33], 14 of which developed anaphylaxis, BAT showed a sensitivity of 42% with an optimum specificity of 100%. No other validated in vitro test exists to date for the diagnosis of this disorder and so it represents an essential aid to diagnosis. 

Many contaminated sites are located in areas with temperatures considerably less than 15°C, and investigations into the role of temperature have therefore been carried out. Some of the cardinal results have been discussed in Chapter 4, and it may be concluded that although the rates at 4-5°C may be low, selection of organisms for adaptation to the ambient temperature will generally ensure that degradative activity is retained. There may, however, be selective degradation of specific groups of components in mixtures such as PCBs. 

Some applications are shown in the following sections, where the standard hardware, software and methods have been partially modified or connected to special experimental constructions. In the past, other applications have been performed by specific groups, who built their own dedicated rf probes and/or gradient systems. These originally specialized products have now found their way into the commercially available NMR microscopy products of today [18, 19]. 

Aggregate risk A measure of the risk to personnel within a building or buildings or within a facility who are impacted by the same events, taking into account the total time spent in the building(s) or facility. (Aggregate risk is "societal risk" applied to a specific group of people within a facility.)... 

Figure 31.2 illustrates the percentages of contribution by each type of radon entry made to a specific group of study houses in the Pacific NW.n Any one house can vary significantly from these figures. However, on a national basis, this is an indication of the relative importance of each of the contributors. 

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