Sampling particulate organic matter from

The samples were analyzed for trace metals and sulfate as well as for three fractions of particulate organic matter (POM) using sequential extraction with cyclohexane (CYC), dichloromethane (DCM) and acetone (ACE). Factor analysis was used to identify the principal types of emission sources and select source tracers. Using the selected source tracers, models were developed of the form POM = a(V) + b(Pb) + - - -, where a and b are regression coefficients determined from ambient data adjusted to constant dispersion conditions. The models for CYC and ACE together, which constitute 90% of the POM, indicate that 40% (3.0 pg/m ) of the mass was associated with oil-burning, 19% (1.4 pg/m ) was from automotive and related sources and 15% (1.1 pg/m ) was associated with soil-like particles. 

Sannigrahi et al. (2005) analyzed 11 DOM samples and five samples of particulate organic matter (POM 0.1-60 pm) that were isolated from seawater using tangential-... 

DOM is composed of small molecules that can be obtained by filtration. Quantification of organic matter in aquatic environment is performed by measuring the concentrations expressed in organic carbon. One measures total organic carbon (TOC) obtained from raw liquid sample, particulate organic carbon (POC) by analyzing the filter, and the dissolved organic carbon (DOC) characterized from the sample after filtration. 

If mean values calculated for the whole water column are compared, especially if the water depth is highly variable between the stations and the number of samples taken from various water layers is different, care must be taken with the interpretation of the results. For instance, mean concentrations of particulate organic matter (POM) calculated for all depths show a gradient (Fig. 12.12) with higher concentrations in the shallow western areas of the... 

Considerable attention has been directed to particulate organic matter (POM) in the marine environment that is plausibly derived from organisms in the euphotic zone. This is supported by MS comparison of pyrolysis products from samples collected in sediment traps in the Mediterranean Sea with that from the diatom Biddulphia sinensis. Although the structures are unknown, a wide variety of compounds have been identified in the pyrolysates including aliphatic hydrocarbons and nitriles, pyrroles, indoles, and aromatic hydrocarbons (Peulve et al. 1996). 

Figure 9 shows vertical G profiles for DIG and DOM as well as " G results for selected samples of sinking and suspended particulate organic matter (POM), HMW DOM, and monosaccharides isolated from selected depths at a station in the North-east Pacific Ocean. Individual monosaccharides were obtained by hydrolysis of HMW DOM, and purified and... 

In this technique, bulk dried samples are heated in an inert helium atmosphere, where upon thermo-vaporization and pyrolysis, hydrocarbons are quantified by flame-ionisation detection. Compounds occurring as free gases and liquids in sediments are separated from those that occur in bound form, or as particulate organic matter by temperature control. The S [-detector signal records free hydrocarbons, which are thermo-vaporizable at 300°C, and the S2-detector signal measures those compounds liberated during programmed pyrolysis from 300 to 550°C. 

SW-846, is used to measure emissions of semivolatile principal organic constituents. Method 0010 is designed to determine destruction and removal efficiency (DRE) of POHCs from incineration systems. The method involves a modification of the EPA Method 5 sampling train and may be used to determine particulate emission rates from stationary sources. The method is applied to semivolatile compounds, including polychlorinated biphenyls (PCBs), chlorinated dibenzodioxins and dibenzofurans, polycyclic organic matter, and other semivolatile organic compounds. 

Bates et al. [35] collected suspended particulate matter from river water and wastewater effluents using high speed continuous flow centrifugation, and analysed the isolated solids for hydrocarbons. The results were compared with those obtained on samples obtained by glass filter filtration. It was concluded that the use of a continuance flow centrifuge allows the concentration of organic associated with suspended particulate matter to be estimated more accurately. 

Filtration. To separate the dissolved from the particulate fraction filtration or centrifugation will be necessary. This causes a severe risk of contamination it is therefore often not carried out with open ocean samples, where the concentrations of suspended material are low. The presence of phytoplankton or a variable concentration of suspended matter affects the total concentration and a comparison of samples can thus become difficult. In speciation Studies the presence of particles may influence the results even more (complexation, adsorption), therefore filtration over acid washed membrane or screen filters in an appropriate filtration apparatus is recommended for all natural samples (Bewers et al., 1985). High pressure during filtration should be avoided ruptured (plankton-) cells will contribute organic matter, nutrients and trace metals to the solution. A pressure < 25 kPa is recommended (Florence and Batley, 1980). 

Former studies by Hodgson et al. (1963) showed that the removal of organic matter, which partly controls CEC, from soils might either increase or decrease adsorption of Cobalt. It is likely that several parameters which are commonly associated with the adsorptive properties of particulate matter do not depend the same way on the constitutive properties of the samples. Nevertheless, it is still difficult ... 

PAHs in soil may partition into soil organic matter (SOM) or adsorb on soil minerals. The sorptive properties of SOM fractions for organic contaminants in soil play an important role on the transportation of PAHs in soil. Xiao et al. (2004) has reported that soil/sediment organic matter can be fractionated into four fractions with a combined wet chemical procedure and that kerogen and black carbon (BC) are major SOM components in soil/sediment samples collected from the industrialized suburban areas of Guangzhou, China. Phenanthrene and naphthalene were used as the sorbates to study PAH s sorption isotherms on four original and four Soxhlet-extracted soil/sediment samples, 15 isolated SOM fractions, and a char as the sorbents. The sorption isotherms of phenanthrene and naphthalene on all the sorbents were variously nonlinear. The particulate kerogen and black carbon (KB) fractions... 

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