Volatile samplers

Figure 5 Example of sampler configurations for (a) low-volume (0.1-5L min ) and (b) high-volume (>5-100Lmin ) determination of trapping efficiency for semi-volatile pesticides, and (c) low-volume (0.1-5 L min ) trapping efficiency for volatile pesticides...

Flg ire 8.29 Apparatus for siunpling airborne organic samples. A, trapping of organic volatiles in air using a sorbent trap B, thermal desorption chamber C, high-volume sampler for air particulates. 

They describe the development of a system employing a Tenax GC filled purge and trap sampler, which collects and concentrates volatile organotins from water samples (and species volatilised by hydrodisation with sodium borohydride), coupled automatically to a gas chromatograph equipped with... 

Bidleman, T.F., N.F. Burdick, J.W. Westcott, and W.N. Billings. 1983. Influence of volatility on the collection of airborne PCB and pesticides with filter-solid adsorbent samplers. Pages 15 18 in D. Mackay, S. Paterson, S.J. Eisenreich, and M.S. Simmons (eds.). Physical Behavior ofPCBs in the Great Lakes. Ann Arbor Science, Ann Arbor, MI. 

In the purge-and-trap procedure, vials filled to the brim with the water samples are loaded into an auto-sampler, and then when the unit is operating, samples are drawn, one by one, into a tube where helium sparging occurs. Because the THMs are volatile, the helium sparging draws them out of the samples. The helium-THM gaseous mixture then flows through a trap in which the THMs are adsorbed and concentrated. This is followed by a desorption step in which the desorbed THMs are guided to the GC column. A Hall detector is used. 

A method was developed and tested for collecting semi- and non-volatile brominated organic compounds from air using a glass fiber filter and a high-volume air sampler. Exposed filters were extracted with acetone and the extracts analyzed by either glc/ms/comp, glc/ecd or tic. Recoveries of selected compounds from the filter material were >87%. 

Crist FIL, Mitchell WJ. 1986. Field audit results with organic gas standards on volatile organic ambient air samplers equipped with Texas GC. Environmental Science and Technology 20 1260-1262. 

K. Gragg, Chemical and Biological Characterization of Particulate-, Semi-volatile-, and Gas-Phase-Associated Compounds in Diluted Heavy-Duty Diesel Exhausts A Comparison of Three Different Semi-volatile-Phase Samplers, Environ. Sci. Technol., 25, 332-338 (1991). 

Evans, M., et al, The Practical Application of the Praton Diffusion Sampler for the Measurement of Time-Weighted Average Exposure to Volatile Organic Substances in Air,... 

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