Semivolatile organic compounds concentration

Prepai ative isolation of nonvolatile and semivolatile organic compounds fractions (hydrophobic weak acids, hydrophobic weak bases, hydrophobic neutrals, humic and fulvic acids) from natural and drinking waters in optimal conditions was systematically investigated by solid-phase extraction method with porous polymer sorbents followed by isolation from general concentrate of antropogenic and/or toxic semivolatile compounds produced in chlorination and ozonation processes. 

During bench-scale studies on ACT using sediments from the New Bedford Harbor Superfund Site, the Toxicity Characteristic Leaching Procedure (TCLP) concentrations of many contaminants increased or remained unchanged following treatment. Based on these results, researchers stated that solidification/stabilization methods such as ACT were not appropriate for the treatment of polychlorinated biphenyls (PCBs) or semivolatile organic compounds (SVOCs) at the site. The study also indicated that the compressive strength of ACT [45 to 80 pounds per square inch (psi)] was relatively low compared to other solidification/stabilization materials that were tested. 

This system is designed to treat volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs) at very high concentrations, which traditional nonvacuum air stripping... 

Organic substances that are not volatile are grouped under semivolatiles. The latter class also includes substances of very low volatility such as chlorinated biphenyls and polynuclear aromatics. As far as the GC/MS technique goes, the principle of analysis of the semivolatile organics is not so distinctly different from that of the volatile organics. On the other hand, the method of extraction of analytes from the sample matrices and the sample concentration steps for these semivolatile organic compounds vastly differ from the volatile organics. Such extraction techniques and the sample cleanup methods are discussed more extensively in Chapter 1.5. 

The experiments carried out diuing the January 2005 EUPHORE campaign consisted mostly of D-1, D4, D-5 and D-7 nms (Table 1). To determine the particle size, number and volume concentrations the Scanning Mobility Particle Analyzer (SMPS) was used and the particle mass was continuously monitored using TEOM. NOx and NOy species were monitored using chemiluminescence and Foiuier Transfer Infrared (FTIR) instruments. After several hours of exposure, the samples for semivolatile organic compound s (SVOC) analysis... 

Wania, F., J-E. Haugen, Y. D. Lei D. Mackay, 1998. Temperature dependence of atmospheric concentrations of semivolatile organic compounds. Environ. Sci. Technol. 31 1013-1021. 

Method 3550 uses sonication with ultrasound to expedite the extraction of nonvolatile and semivolatile organic compounds from solids including soils, sludges, and wastes. The procedure calls for subjecting the finely divided dried sample mixed with solvent to ultrasound for a brief period of time. Low-concentration samples can be subjected to multiple extractions with additional fresh solvent. 

As discussed in this book, certain sample preparation techniques are clearly more appropriate for volatile compounds than for semivolatile and nonvolatile compounds. In this chapter we concentrate on extraction methods for semivolatile organics from liquids. Techniques for extraction of volatile organics from solids and liquids are discussed in Chapter 4. 

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