Chemical sensing, with near

Although composed of weak and overlapping spectral features, near-infrared spectra can be used to extract analytical information from complex sample matrices. Chemical sensing with in-line near-infrared spectroscopy is a general technique that can be used to quantify multiple analytes in complex matrices, often without reagents or sample pretreatment.7-9 Applications are widespread in the food sciences, agricultural industry, petroleum refining, and process analytical chemistry.10-13 These activities demonstrate that near-infrared spectroscopy can provide selective and accurate quantitative measurements both rapidly and nondestructively. 

In the discussion about how we should set up our chemical process industry in the near future, the sustainability issue is of prime importance. Sustainability in the ecological sense means that we do not place an intolerable load on the ecosphere and that we maintain the natural basis for life. The complexity of the chemical industry with its numerous products has made us lose sight of the associated ecological impact of these products life cycles When you produce something, you also produce long-term effects. In economics, this concept is known as joint production [17], and we will discuss this in Section 13.6. 

As mentioned, there are four categories of CWA blood, choking, vesicant (blister), and nerve agents. Each agent has a simulant which is not as toxic as the real gas but that should have nearly the same chemical reactions with the surfaces of the sensing materials (metal oxides or polymers). 

The results for both R. cascadae and R. aurora showed that tadpoles discriminated between kin and nonkin based on chemical cues. Test individuals spent significantly more time near stimulus groups composed of kin than those composed of nonkin when their chemical senses were not impaired. The sham controls in the R. aurora tests also discriminated between kin and nonkin. Tadpoles did not discriminate between kin and nonkin when provided with visual cues alone. Sound production played no role in kin discrimination (Blaustein O Hara 1982). 

Whilst the primary applications of Pd nanopartides have been in catalysis, a number of reports have described other important applications related to the life sciences. Scheme 9.2 shows several such uses of Pd nanopartides, although for the purpose of this chapter we focus on those applications in the white boxes as these relate to the life sciences. They include the role of Pd in environmental remediation, as well as in biological and chemical sensing. It is anticipated that, with the recent successes in controlling the shape of Pd nanopartides and an improved understanding of their chemical and physical properties, a host of new applications will be discovered in the near future. 

Surface acoustic wave (SAW) devices have been studied in detail for chemical sensing applications (1-12). Nearly all this work has relied on some sort of chemically sensitive interface, many of which, however, are not particularly chemically selective. Table I summarizes the different classes of materials that have been examined for SAW-based chemical sensing applications, with a few examples in each category. Bearing in mind that SAW devices respond to changes in mass/area, none of the materials in Table I can be claimed to be entirely immune to interference fi om nonspecific adsorption, particularly for interferants vrith vapor pressures significantly below ambient pressure. 

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