Biogenic organics

Amino acid measurements in ALH84001 are almost certainly the result of Antarctic ice contamination. Amino acids are readily soluble in water but PAHs are practically insoluble. Isotopic measurements of 14C show that terrestrial carbon is incorporated into the meteorite during extended stays in the Antarctic ice fields. In addition, microbial activity on the exposed surfaces provides an additional source of biogenic organic material that may be incorporated over time. 

Winer, A.M., Atkinson, R., Pitts, J.N., Jr. (1984) Gaseous nitrate radical possible nighttime atmospheric sink for biogenic organic compounds. Science 224, 156-159. 

Cindy Lee is a Professor at the Marine Sciences Research Center of Stony Brook University. Dr. Lee s research examines the distribution and behavior of biogenic organic compounds, in particular the rates and mechanisms of transformation reactions occurring as these compounds undergo alteration. Her research investigates organic compounds in the sediments and waters of open ocean and coastal areas, salt marshes, lakes, as well as the atmosphere above these areas. Her expertise centers on the analytical techniques used to measure organic matter in the ocean. Dr. Lee is cur-... 

Atkinson, R. and Arey, J. Atmospheric chemistry of biogenic organic compounds, Acc. Chem. Res., 31(9) 574-583,1998. 

Variations in content of some important carbon compounds are schematically demonstrated in Fig. 2.11 The two most important carbon reservoirs on Earth, marine carbonates and the biogenic organic matter, are characterized by very different isotopic compositions the carbonates being isotopically heavy with a mean 5 C-valne around 0%c and organic matter being isotopically light with a mean 5 C-value aronnd -25%c. For these two sedimentary carbon reservoirs an isotope mass balance mnst exist such that ... 

Gas-phase chemistry in remote areas is, in most cases, analogous to that in more polluted regions. The major difference is in lower NOx emissions and hence concentrations. In addition, in continental regions, there are substantial emissions of biogenic organics, many of which are highly reactive toward OH, 03, N03, and Cl atoms and in oceanic regions, dimethyl sulfide (DMS), which reacts with OH, N03, and Cl atoms. 

In short, while a variety of oxygen-containing biogenic organics have been obseived to be generated from plants and most are likely direct emissions, care must be taken to distinguish such direct emissions from... 

Atkinson, R., and J. Arey, Atmospheric Chemistry of Biogenic Organic Compounds, Accounts Chem. Res., 31, 574-583 (1998). 

Finlayson-Pitts, B. J., C. J. Keoshian, B. Buehler, and A. A. Ezell, Kinetics of Reaction of Chlorine Atoms with Some Biogenic Organics, Int. J. Chem. Kinet., 31, 491-499 (1999). 

Similar biogenic organics and their distributions have been noted in a variety of locations, including the Amazon, China, and over the south Atlantic area (e.g., see Simoneit et al., 1990, 1991a, 1991b). They are also found in urban areas but generally comprise a small fraction of the total aerosol mass for example, they are about 1-3% of the total fine particulate matter in the Los Angeles area (Hildemann et al., 1996). 

Formaldehyde is a designated HAP/TAC. As we have seen on many occasions throughout this book, it not only is directly emitted by a number of sources, including by motor vehicles outdoors and by building materials indoors (see Chapter 15.D), but is also formed in air from the oxidation of both anthropogenic and biogenic organics. 

Table 3 also shows that an MD factor resolved by receptor modelling (PMF) reveals higher concentrations than tracer-based calculations. This may be due to the fraction of biogenic organic matter being present in soils unaccounted by tracer approaches. 

Geckeler KE, Eberhardt W (1995) Biogenic Organic Chlorinated Compounds - Occurrence, Function and Environmental Relevance. Naturwissenschaften 82 2... 

A hypothetical aerosol size/composition distribution is shown in Figure 12.1, indicating that crustal materials (e.g., COf, Si, Al, Fe, Ca, and Mn), sea spray (e.g., Mg, Na, and Cl), and biogenic organic particles (e.g., pollen, spores, and plant fragments) are usually found in the coarse aerosol fraction (2.5 < r/ae < 10pm) (Meszaros et al., 1997 Krivacsy and Molnar, 1998 Matsumoto et al., 1998 Seinfeld and Pandis, 1998 Maenhaut et al., 2002 Smolik et al., 2003). Wind erosion, primary emissions, mechanical disruption, sea spray, and volcanic eruptions all contribute to the concentrations of these species (Seinfeld, 1986 Seinfeld and Pandis, 1998). 

Gagosian, R.B., Nigrelli, G.E., and Volkman, J.K. (1983) Vertical transport and transformation of biogenic organic compounds from sediment trap experiment off the coast of Peru. In Coastal Upwelling Its Sediment Record. Part A. Response of the Sedimentary Regime to Present Coastal Upwelling (Suess, E., and Thiede, J., eds.), pp. 241-272, Plenum Press, New York. 

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