Polyaromatic hydrocarbons monitoring

Funk et al. [128a] dipped silica gel plates in a 4% solution of caffeine in order to separate six polyaromatic hydrocarbons relevant in monitoring the quality of potable water (Fig. 42). 

In this study the soil samples were spiked with labelled and unlabelled benzo[<2]pyrene, or anthracene at 5 and 50pg/g soil. The samples were incubated in biometer flasks at 20°C for three and five months for anthracene and benzo[a]pyrene, respectively, allowing degradation to be monitored and the polyaromatic hydrocarbon to interact with the soil matrix. 

Dunn and Stich [78] and Dunn [79] have described a monitoring procedure for polyaromatic hydrocarbons, particularly benzo[a]pyrene in marine sediments. The procedures involve extraction and purification of hydrocarbon fractions from the sediments and determination of compounds by thin layer chromatography and fluorometry, or gas chromatography. In this procedure, the sediment was refluxed with ethanolic potassium hydroxide, then filtered and the filtrate extracted with isooctane. The isooctane extract was cleaned up on a florisil column, then the polyaromatic hydrocarbons were extracted from the isoactive extract with pure dimethyl sulphoxide. The latter phase was contacted with water, then extracted with isooctane to recover polyaromatic hydrocarbons. The overall recovery of polyaromatic hydrocarbons in this extract by fluorescence spectroscopy was 50-70%. 

T. Vo-Dinh, G. D. Griffin, K. R. Ambrose, and M. J. Spaniak, Fiberoptics immunofluorescence spectroscopy for chemical and biomedical monitoring, in Polyaromatic Hydrocarbons A Decade of Progress (M. Cooke and A. J. Dennis, eds.), pp. 885-890, Battelle Press, Columbus, Ohio (1988). 

Vrana, B. Paschke, A. Popp, P. 2001a, Polyaromatic hydrocarbon concentrations and patterns in sediments and surface water of the Mansfield Region, Saxony-Anhalt, Germany. J. Environ. Monitor. 3 602-609. 

New York Developing capacity to monitor for polyaromatic hydrocarbons (PAHs) in urine, polybrominated diphenyl ethers (PBDEs) in serum, organochlorine pesticides in serum, volatile organic compounds (VOCs) in blood, cotinine in saliva, trace elements in blood and urine, inorganic mercury in blood and to generate data on exposure to persistent organic pollutants (CDC 2005). 

Because of the extensive reuse of combustion air in the process at Calaveras facility, the fabric filter exhaust is the only point of emissions for the kiln, clinker cooler, and raw mill. Exhaust gases from the fabric filter are monitored continuously for carbon monoxide, nitrogen oxides, and hydrocarbons. Calaveras has tested toxic pollutants while burning 20 percent TDF. Table 4-5 summarizes these test results, giving emission factors for metals, hazardous air pollutants, polyaromatic hydrocarbons, dioxins and... 

Vondracek, J., M. Machala, K. Minksova, et al. 2001. Monitoring river sediments contaminated predominantly with polyaromatic hydrocarbons by chemical and in vitro bioassay techniques. Environ. Toxicol. Chem. 20 1499-1506. 

In studies of tar cracking using a separate catalyst bed, two types of tar sources are applied, one directly drawn from a biomass gasifier and the other from model compounds. According to VTTs work [12], the tar consists mainly of highly stable compounds such as benzene (60-70 wt %), naphthalene (10-20 wt %), and other polyaromatic hydrocarbons (10-20 wt %), which can amount to 15-20 g of tar/Nm in biomass gasification. So, benzene and naphthalene were used in this work as tar model compounds with a fixed concentration of 15 g/Nm (4300 ppm) for benzene and 5 g/Nm (875 ppm) for naphthalene, respectively. The gas composition used was 50 vol % N2, 12 vol % CO, 10 vol % H2, 11 vol % CO2, 12 vol % H2O, 5 vol % CH4, 4300 ppm benzene (or 875 ppm naphthalene), which is a typical composition of the product gas from a biomass fluidised bed gasifier operated with air. The reaction tests were performed under three filtration gas velocities 2.5, 4 and 6 cm/s. All experimental points were monitored for at least 60 min after the reaction reached an apparent steady state at the selected operation condition. 

The risk assessment process was incomplete because there was a lack of test results for many pollutants, and many test results were not completed for a number of days after sampling. There was also an absence of shortterm health benchmarks for asbestos and other pollutants, and problems with asbestos monitoring. EPA did not have monitoring data to support reassurances made in their early press releases, because they lacked monitoring data for several contaminants, such as PCBs, particulates, dioxin, and polyaromatic hydrocarbons. 

Increasing redox efficiency to 100% provides a useful means of on-line electrochemical deiivatization for subsequent detection downstream. The products may be monitored electrochemically or optically. For example, nitrosubstituted polyaromatic hydrocarbons may be reduced to their corre-qx>nding amines via a packed bed unlike the parent compounds, these products are readily fluorescent. 

Polyaromatic hydrocarbons (PAHs) and alkyl-substituted PAHs were extracted, isolated, and analyzed from Hinkel Reservoir sediments using a variation of the procedure of Furlong et al. (1995). Variations include the addition of a silica column cleanup step following the gel permeation chromatography cleanup step and the use of selected ion monitoring (SIM) MS to reduce chemical interferences and improve detection limits. 

Biological monitoring techniques such as immunoassays are now available for environmental analysis. These form the basis of low cost, rapid, and highly selective kits for the determination of specific compounds or classes of compounds, such as polyaromatic hydrocarbons, polychlorinated biphenyls, pesticides, herbicides, and insecticides, in food, water, and soil matrices. They are simple to use and are well suited to screening sites for contamination prior to sampling and laboratory analysis. Immunoassays can also be applied to blood and urine samples for assessing the exposure of organisms to contaminants. 

Fernandez and Bayona [618] developed a method for the fiactionation of polyaromatic hydrocarbons from dichloromethane extracts of air particulates and marine sediment. The resulting fractions were quantitated by GC/MS. A silica column I = 254 nm or 254 nm, ex 390 nm, em) generated the following fractions PCB, PAH, N02-PAH/2°-amine-PAH, keto-PAH, keto-PAH/quinones, quinones, 3°-amine-PAH, and 3°-amine-PAH/hydroxy-PAH. The separation required a 70-min 100/00/100 hexane/dichloromethane gradient. Levels of 47 compounds were monitored, typically well below the pg/g range. 

Monitoring and control of pollutants The presence of heavy metals (for example lead, cadmium and mercury), organic chemicals (for example polychlorinated biphenyls (PCBs)) and vehicle exhaust gas emissions (polyaromatic hydrocarbons (PAHs)) are all health hazards that need to be monitored by accurate methods of analysis. Atmospheric pollutants also need to be monitored. 

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