Polyurethane foam plug

Application verification (AV) monitors are devices that are placed within test plots to measure actual spray deposition that occurred during application. The main function of AV monitors is to show whether or not the intended amount of test material was actually deposited on the soil surface. Application monitors consisting of soil-filled containers, paper disks, polyurethane foam plugs, and glass Petri dishes have all been used successfully for this purpose. Prior to using a monitor in the field, it is important to determine that the test substance can indeed be successfully extracted from the monitor and that the compound will be stable on the monitor under field conditions... 

Aira Adsorption/solvent extraction with polyurethane foam plug HRGC/MS No data No data Ligocki and Pankow 1985... 

For example, Fig. 10.37 shows a mutagram of an extract of ambient gas-phase POM collected on polyurethane foam plugs in Claremont, California, along with mutagrams of the extracts of PUF samples collected from environmental chamber studies of the OH radical initiated reactions of fluorene and naphthalene, respectively (Arey et al., 1992 Harger et al., 1992 Atkinson and Arey, 1994). Clearly, the mutagrams from the OH-initiated reactions are very similar to that of ambient air. 

Air (CDDs) Collection of sample onto quartz fiber/polyurethane foam plug Soxhlet extraction with acetone clean-up with hexane and sulfuric acid followed by silica gel and alumina columns HRGC/MS (SIM) 0.5 pg/m3 70-90 Kuwata et al. 1993... 

In further work Saxena et al. [513] and Basu and Saxena [36] showed that the polyurethane-foam plug method had an extraction efficiency for PAHs of at least 88% from treated waters and 72% from raw water. 

Air Collected on XAD-2 resin sandwiched between polyurethane foam plugs, Soxhlet extracted with 6% ether/hexane GC/MS 1.0691 g / extract 114 Rudel et al. 2001... 

Air samples were taken at Ross Island, Cape Evans, and processed by filtering through polyurethane foam plugs connected in series (76). After extraction with an acetone-hexane mixture, determinations of 24 PCB congeners, p,p -DDT, p,p -DDE and lindane were accomplished by capillary GC with EC detection. Geochemical means (in pg m ) were 15.2, 2.0, 1.0 and 25.8 for the above compounds in the given order. Lindane concentrations were found to correlate well with seasonal variations (higher levels in summer and autumn), whereas the other chlorinated hydrocarbons showed no dependence on seasons. 

The sample was collected using a high-volume air sampler, in which 13,000 m of air was sampled over a 7-day period. Air was aspirated through a glass fiber filter and two polyurethane foam plugs. Samples were subjected to Soxhlet extraction... 

While air and atmospheric analyses have been the subjects of many research articles, chromatographic determinations of pesticides in these types of sample are scant. Various methods for sampling pesticides in air have been reported, which use silica gel, Tenax, Chromosorb, XAD-2, polyurethane foam plug, glass fiber filters, and activated carbon or carbon fiber filters as sampling... 

Air samples were taken in a central location of the crawl space, the kitchen, and a bedroom with personal-type air samplers (10). Polyurethane foam plugs (2 cm od. by 3 cm) contained in a glass holder were attached to the sampler. A 2-h sample was taken at a flow rate of 2.8 L of alr/mln. The holder and foam were removed, placed in plastic bags, and stored at -20C until analyzed. 

Figure 3 Minicartridges for use as personai sampiers for gases or vapors. (A) Charcoai or siiica gei tube for sampiing organic vapors 1, spring stopper 2, quartz wooi 3, glass tube 4, 20-40 mesh charcoal or silica gel (200 mg) 5, polyurethane foam plug. (Courtesy of Sibata Scientific Technology, used by permission.) (B) Sep-Pak cartridges. (Courtesy of Waters Corporation, Milford, MA, USA, used by permission.)...

In the original work on vapour cooled baffles published in 1965 [2], expanded polystyrene or polyurethane foam plugs were demonstrated to be as effective as horizontal baffles and this finding led directly to the widespread use of foam plugs. However, subsequent work, pubUshed in 1969 [3], demonstrated clearly that foam plugs become unreliable and ineffective insulators after continuous exposure to boil-off gas over a few days. 

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