Volatile organic compound components

For aqueous inks, the resins are water- or alkali-soluble or dispersible and the solvent is mosdy water containing sufficient alcohol (as much as 25%) to help solubilize the resin. To keep the alkah-soluble resin in solution, pH must be maintained at the correct level. Advances include the development of uv inks. These are high viscosity inks that require no drying but are photocurable by uv radiation. In these formulations, the solvent is replaced by monomers and photoinitiators that can be cross-linked by exposure to uv radiation. The advantage of this system is the complete elimination of volatile organic compounds (VOC) as components of the system and better halftone print quaUty. Aqueous and uv inks are becoming more popular as environmental pressure to reduce VOC increases. 

Many components of ships and marine stmctures are now coated in the shop under controlled conditions to reduce the amount of solvents released into the atmosphere, improve the quaUty of work, and reduce cost. Regulations designed to limit the release of volatile organic compounds into the air confine methods of shop apphcation to those having transfer efficiencies of 65%. Transfer efficiency is defined as the percent of the mass or volume of sohd coating that is actually deposited on the item being coated, and is calculated as... 

The volatile organic compound geraniol, a component of oil of roses, is used in perfumery. The density of the vapor at 260.°C and 103 Torr is 0.480 g-L. What is the molar mass of geraniol ... 

As discussed in Chapter 7, gas chromatography (GC) is used to separate complex mixtures of volatile organic compounds. However, unless pure authentic standards are also analyzed to compare retention times, it is not possible to identify the components by GC alone. However, by connecting the output of a GC to a mass spectrometer, and by removing the carrier gas to maintain the low pressures required, it is possible to both separate and identify these complex mixtures. This method is the gold standard for the identification of organic samples, if they are sufficiently volatile. 

This is an alternative technique to headspace analysis for the identification and determination of volatile organic compounds in water. The sample is purged with an inert gas for a fixed period of time. Volatile compounds are sparged from the sample and collected on a solid sorbent trap—usually activated carbon. The trap is then rapidly heated and the compounds collected and transferred as a plug under a reversed flow of inert gas to an external gas chromatograph. Chromatographic techniques are then used to quantify and identify sample components. 

One of the key components of any green industrial process has to be the selection of the solvent, since working with conventional solvents results in the emission of volatile organic compounds (VOCs), a major source of environmental pollution (see Figure 5.4). There are four principal strategies to avoid conventional organic solvents ... 

In the following discussion, three types of air pollutant analytical data will be examined using principal component analysis and the K-Nearest Neighbor (KNN) procedure. A set of Interlaboratory comparison data from X-ray emission trace element analysis, data from a comparison of two methods for determining lead In gasoline, and results from gas chromatography/mass spectrometry analysis for volatile organic compounds In ambient air will be used as Illustrations. 

VESTRIP is a system designed for the in situ treatment of soils contaminated with volatile organic compounds (VOCs) benzene, toluene, ethylbenzene, and xylenes (BTEX) and other contaminants that are amenable to soil vapor extraction (SVE). The vendor, Ejector Systems, Inc. (ESI) has combined the key components of SVE systems with an air stripper to form a product that performs the functions of both. The name, VESTRIP, is a contraction of VES (vapor extraction system) and air stripping. 

The low-temperature thermal aeration (ETTA) technology is a thermal desorption process that separates chlorinated hydrocarbons, volatile organic compounds (VOCs), semivolatile organic compounds (S VOCs), pesticides, and petroleum hydrocarbons from soils at temperatures of 300 to 800° F. This technology uses hot air to desorb contaminants from soil into a contained airstream and treats the airstream before discharging it to the atmosphere. The system is transportable and consists of six major components assembled on flat-bed trailers. The entire system and support areas require approximately 10,000 ft of operating space. 

IC can also be used in detection of some acids. Zhao et al. [25] proposed a simple and eco-friendly ion chromatographic method for the determination of Hippuric acid (HA) in human urine (see Figure 12). Hippuric acid is a kind of metabolite of toluene in human body, therefore, HA is a physiological component of human urine if toluene was inhaled. The content of HA in human urine actually is confirmed as a diagnostic marker of exposure to toluene [26]. It has been reported that exposure to high concentrations of volatile organic compounds such as... 

Volatile organic compounds (VOC) are ubiquitous components not only of ambient air but also of indoor... 

Rappaport, S.M., Selvin, S., Waters, M.A. (1987) Expostrres to hydrocarbon components of gasoline in the petrolerun indtrstry. Appl. ind. Hyg., 2, 148-154 Sack, T.M., Steele, D.H., Hammerstrom, K. Remmers, J. (1992) A survey of household products for volatile organic compounds, Environ., 26A, 1063-1070... 

Figure 2.13—Detection by mass spectrometry. TIC chromatogram obtained with a mass spectrometer as a detection system. The instrument is capable of obtaining hundreds of spectra per minute. The above chromatogram corresponds to the total ion current at each instant of the elution profile. It is possible to identify each of the components using its mass spectrum. In many instances, compounds can be identified with the use of a library of mass spectra. (Chromatogram of a mixture of 71 volatile organic compounds (VOCs), reproduced by permission ofTekmarand Restek, USA.)...

Each of these considerations must be resolved before a personal monitor can be applied to air pollution research and characterization studies. Some advances have been made for carbon monoxide, volatile organic compounds, acid aerosols, and particulate matter (PM-10 and RSP these represent the masses of all particles collected in samplers with 50% cut sizes of 10 and 25 xm, respectively) and its components (12, 22-31). Each advance is still undergoing development, and further advances can be anticipated for these as well as for other pollutants. The next generation of monitors will probably include devices for some pollutants that incorporate the use of microsensors. Currently, microsensors are being examined for detection of nitrogen dioxide and ozone, but the range of sensors available suggests that they can be used for a number of compounds (10, 32) ... 

Decreases in nitrogen oxide emissions are also expected to have positive health effects by reducing the nitrate component of inhalable particulates and reducing the nitrogen oxides available to react with volatile organic compounds (VOCs) and form ozone. Ozone impacts on human health include a number of morbidity and mortality risks associated with lung disorders. 

Clean Air Act Amendments. The CAA define the components of an ink formula that are regarded as volatile organic compounds (V OCs). Emissions from ink formulations during the printing process are still considered to be a significant source of air pollution. This regulation continues to be the principal impetus to the introduction of ink technologies that offer alternatives to traditional solvent-based ink chemistries. 

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