Chemical Imaging for PAH Analysis in Particulate Materials

Abstract

Chemical imaging is a new analytical science, related to a combination of spatial and chemical resolutions. Several new chemical imaging tools have been developed and applied to environmental analysis. The advantages of such methods, which provide simultaneous morphological/geometrical and chemical speciation, are pointed out and exemplified in several environmental analytical applications. These include fast analysis of PAH contaminated aerosols at low concentrations, analysis of contaminated quartz sand particles, as well as improvement of laser induced fluorescence detection of PAH compounds in natural water, in the presence of various microparticles. It is shown that chemical imaging has a considerable potential in environmental applications and can provide detailed and unique information when particulate materials are concerned.     

The Determination of Polycyclic Aromatic Hydrocarbons in Indigenous and Transplanted Mussels (Mytilys Edulis L.) Along the Dutch Coast

Abstract

A method, originally developed to investigate the pollution of Dutch coastal water with metals and PCBs,¹ was modified for the determination of the pollution with polycyclic aromatic hydrocarbons (PAH).

The method is based on active biological monitoring with mussels (Mytilus edulis L.). Its usefulness has already been demonstrated.² In the present study a method for the determination of PAH in mussels has been developed. The method is based on the hydrolysis of tissue with 4 M sodium hydroxide, extraction with hexane, clean-up with 10% deactivated aluminium oxide and quantitative determination with Reversed Phase High Performance Liquid Chromatography (RP-HPLC) and fluorescence detection.

The accumulation plateau of most of the PAH studied has not been reached after 60 days. Gradients of pollution were found, and at least one significant source near IJmuiden was detected.     

Identification Of Oxygen Derivatives Of Polycyclic Aromatic Hydrocarbons In Airborne Participate Matter Of Upper Silesia (Poland)

Abstract

Organic material extracted from airborne participate matter collected in various places of Upper Silesia has been separated by column liquid adsorption chromatography. Six fractions of different polarity have been eluted. These fractions have undergone careful spectral analysis, thin layer chromatography and gas chromatography-mass spectrometry. Several PAH oxygen derivatives which have not been found in air from our Region so far were identified. Their biological activity is higher than activity of basic PAH structures. These compounds can be responsible to a high degree for interference in living organism functions in this highly polluted region.     

The Identification of Polynuclear Aromatic Hydrocarbon (PAH) Derivatives in Mutagenic Fractions of Diesel Particulate Extracts

Abstract

The soluble organic fraction (SOF) of particulate matter from diesel exhaust (from point sources, ambient air, etc.) contains hundreds of organic constituents. Normal-phase high pressure liquid chromatography (HPLC) has been used to separate the SOF into sub-fractions suitable for subsequent chemical analysis and bioassays. These fractions consist of non-polar(PAH), moderately polar (transition) and highly polar constituents. The non-polar fractions have been well characterized and consist of PAH and aliphatic hydrocarbons. The specific compounds present in the transition and polar fractions are for the most part unknown. This analytical information has been difficult to obtain since these compounds are highly labile, polar, of low volatility and in very low concentrations when compared to the bulk of material found in the SOF. Mutagenicity tests using the Ames Salmonella typhimurium assay indicate that the transition fraction accounts for most of the mutagenicity when compared to the non-polar (PAH) and polar fractions.

A variety of chromatographic and mass spectrometric techniques are described that have been used to determine the composition of the HPLC fractions. More than one hundred species have been identified in the transition fraction of diesel particulate matter using high resolution gas chromatography (HRGC)/high resolution mass spectrometry (HRMS), HPLC and direct-probe high resolution mass spectrometry. It has been found that the transition fraction contains mostly PAH derivatives consisting of hydroxy, ketone, quinone, carboxaldehyde, acid anhydride and dihydroxy derivatives of PAH. Three nitro-PAH species have been tentatively identified and 1-nitropyrene positively identified in the transition fraction. The 1-nitropyrene was found to account for approximately 45% and 30% of the direct-acting mutagenicity observed for the transition fraction and total extract, respectively. The HPLC separation procedure was shown to give better than 95% recovery of the mass and mutagenic activity. The problem of PAH oxidation during the analytical procedures and possible effect on bioassay results are discussed.     

A Study On Air Pollution by Asphalt Fumes

Abstract

A TLC/HPLC procedure for the determination of polycyclic aromatic hydrocarbons (PAH), occuring in asphalt fumes (adsorbed on particular matter), is described. The method is based on extraction of asphalt fume particles, collected on glass fibre filters, using CCK₄. Following a clean up step by the aid of a TLC procedure on Al₂ O₃ thinlayer plates, using a mixture of cyclohexane/acetone/ether as the mobile phase. Under UV-light, occuring PAH are indicated as fluorescent spots. A separation of the collected PAH into individual components and their identification is performed by the aid of a HPLC procedure. Futher-more, an approach was made to verify the separated PAH by their fluorescence spectra and their mass spectra.     

Isolation of Stable Mutagenic Photodecomposition Products of Benzo(a)pyrene by Thin-Layer Chromatography

Abstract

Polycyclic aromatic hydrocarbons (PAH) are widespread in the atmosphere, the soil, waterways and oceans, as well as in the food chain. Major sources of PAH include emissions from transportation systems, heat and power generating plants, refuse burning and industrial processes (1,2,3). A significant number of these PAH are known to be carcinogenic (2,4,5). Epidemiological studies indicate that the environment is a significant factor in the incidence of human cancer, although many of the specific causal agents remain to be identified. One widely studied PAH i s benzo(a)pyrene (BaP), which is a carcinogen, and one of the most common PAH contaminants of the environment (6). Occupational exposure t o BaP has been documented (4). Mailath and Morik (7) studied the effect of sunlight and dark-room storage on BaP and reported that six and eight compounds, respectively, were observed when BaP was exposed to sunlight or left in the dark. There have been several reports of the degradation of BaP adsorbed on soot or smoke particles (8,9,10).     

Analytical Determination of Polycyclic Aromatic Hydrocarbons in Gases from Coal Conversion by Synchronous Fluorescence Spectrometry.

Abstract

A method to analyze the most hazardous Polyclyclic Aromatic Hydrocarbons (PAH) (acenaphtene, anthracene, benzo(a) anthracene, benzo(a)pyrene, biphenyl, coronene, chrysene, dibenzo (a,h) anthracene, phenantrene, fluoranthene, fluorene, naphtalene and pyrene), by using excitation and energy constant synchronic fluorescence has been researched in depth in this study.

Spectral studies carried out allow characteristic peaks to be obtained for the qualitative identification of 8 from 11 PAH tested. From the quantitative and interference studies, the most important analytical characteristics (linear range, detection limit and reproduciblity) for the determination of ten of these compounds have been obtained.

The method was applied to the PAH determination in two different samples: 1) air filter samples for urban pollution control and 2) air samples from a laboratory scale coal carbonization oven. Fluorene (in the first type) and benzo (a) pyrene (in the second type), were identified and quantified.     

Origin of Polycyclic Aromatic Hydrocarbons (PAH) in Recent Sediments from the Continental Shelf of the “Golfe de Gascogne” (Atlantic Ocean) and in the Gironde Estuary

Abstract

Several aromatic series have been analysed on sediment extracts by high performance liquid chromatography coupled (HPLC) and by high resolution Shpol'skii spectroscopy. HPLC coupled to a programmable spectrofluorometer as detector has been used for the detection of the sixteen PAH priority pollutants recommended by the US Environmental Protection Agency. Relative distribution in methylated phenanthrene, chrysene, and pyrene series have been examined by high resolution spectrofluorometry in Shpol'skii matrices for the determination of the sources of aromatic matter in the sediments. These complementary studies would provide useful information on the origin of PAH in marine sediments.     

Microcolumn Liquid Chromatography Combined with Computer-Assisted Retention Prediction System for Polycyclic Aromatic Hydrocarbons in Extract from Diesel Particulate Matter

Abstract

Recent advances in column and instrument technology have made the development of d new generation of high-resolution microcolumn liquid chromatography possible. In addition to offering reduced solvent consumption, this chromatographic technique also yields higher mass sensitivities than those in conventional systems. In this study, the applicability of this technique to the analysis of polycyclic aromatic hydrocarbons (PAH) is investigated. PAH in the extract from diesel particulate matter were analyzed to demonstrate the utility of this approach combined with the computer-assisted retention prediction. The technique proposed in this study makes very clean and high cost-performance environmental analysis possible.     

Analysis of Polycyclic Aromatics

Abstract

Polycyclic aromatic hydrocarbons (PAH), among them carcinogenic compounds, have been found to be widely distributed in the human environment. The formation of PAH in processes relevant to environmental pollution will be described (pyrolysis or incomplete combustion of aliphatic and aromatic material, formation in higher plants). The application of the following methods to the analysis of PAH mixtures will be discussed: gas chromatography (capillary columns, use. of liquid crystals and inorganic salts such as LiCl or Cacl₂, as stationary phases in packed columns, selective detectors); luminescence spectroscopy (use of phosphorescence in paper and thin-layer chromatography, Shpol'skii spectra, quenchofluorimetry; mass spectroscopy.     

Improving the Fluorescence Detectability of Polycyclic Aromatic Hydrocarbons for Evaluation of Workplace Environments of Cement Industries Processing Organic Residues

Abstract

The burning of organic residues and wastes in furnaces of cement industries has been an attractive and lucrative approach to eliminate stocks of these pollutants. There is a potential risk for producing PAH in the workplace of industries burning organic wastes, so that highly sensitive analytical methods are needed for monitoring the air quality of these environments. An official method for determination of PAH is based on liquid chromatography with fluorescence detection at fixed excitation and emission wavelengths. We demonstrate that a suitable choice of these wavelengths, which are changed during the chromatographic run, significantly improves the detectability of PAH in atmosphere and particulate matter collected in cement industries.     

The Application of Perdeuterated Polycyclic Aromatic Hydrocarbons (PAH) as Internal Standards for the Liquid Chromatographic Determination of PAH in a Petroleum Crude Oil and Other Complex Mixtures

Abstract

A sequential liquid chromatographic (LC) procedure for the determination of polycyclic aromatic hydrocarbons (PAH) in a petroleum crude oil and other complex mixtures is described. The procedure includes normal-phase LC on an aminosilane column to isolate fractions containing isomeric PAH and reversed-phase LC on a polymeric C₁₈ column to separate the individual PAH isomers. Appropriate perdeuterated PAH are added to the sample so that each isomeric fraction will contain one internal standard. The perdeuterated PAH are excellent internal standards for this sequential LC procedure. Perdeuterated PAH have normal-phase and reversed-phase LC retention characteristics similar to those of the parent PAH. In the normal-phase LC separation, the perdeuterated PAH elute in the same fraction as the parent PAH. In the reversed-phase LC separation, the perdeuterated PAH elute first and are generally resolved from the parent PAH. The optimized spectrofluorometric detection of each PAH analyte is accomplished by programming appropriate sets of excitation and emission wavelengths to correspond with the elation time of each analyte on the polymeric C₁₈ column. The analytical results obtained from this procedure for the analysis of a shale oil sample [Standard Reference Material (SRM) 1580] and a petroleum crude oil (SRM 1582) are compared to values obtained by gas chromatography - mass spectrometry.     

Optimization of An On-Line Precolumn Preconcentration Method for the Determination of Polycyclic Aromatic Hydrocarbons (PAHs) in Water Samples (River and Sea Water)

Abstract

A new on-line precolumn preconcentration method for the determination of EPA priority pollutants (PAHs) in river and sea water has been developed. The retention time for each PAH in the precolumn has been determined for several percentages of organic solvent (acetonitrile) in the sample. This is very important because recoveries show a great dependence on this parameter.

The proposed procedure, combined with HPLC and spectrofluorimetric detection, reaches very low detection limits (subnanograms per liter) and it has been applied to river and sea water samples with good results.     

Selective Quenchofluorometric Detection of Fluoranthenic Polycyclic Aromatic Hydrocarbons in High-Performance Liquid Chromatography

Abstract

The phenomenon of fluorescence quenching was used for selective HPLC detection of fluoranthenic polycyclic aromatic hydrocarbons (PAH). Termed a “Quenchofluorometric” detection system, it employs a filter fluorimeter or spectrofluorimeter and nitromethane in the mobile phase as the fluorescence quenching reagent. Chromatograms obtained with and without the quenching reagent are compared for PAH standards, a coal tar extract, and a shale oil sample. The quenchofluorometric detection system provides an inexpensive method to achieve selective detection for fluoranthenic PAH as a group.     

Analytical Standards and Methods for the Determination of Polynuclear Aromatic Hydrocarbons in Environmental Samplest

Abstract

Standard reference materials (SRM's) have been produced, certified, and issued by the United States National Bureau of Standards (NBS) since 1905. NBS currently issues more than 1000 SRM's of various types, including nuclear materials, rubber, clinical and environmental trace metal standards. The most recent addition to this group is a series of environmental trace organic materials with certified concentrations of selected polynuclear aromatic hydrocarbons (PAH), phenols, and N-heterocyclic compounds. Until recently, trace organic SRM's were non-existent due to the lack of analytical methodology necessary for certification. Details concerning the analytical methods developed and used for certification of the concentrations of several PAH in SRM's 1580 (Organics in Shale Oil), 1644 (Generator Columns for PAH in water), 1647 (PAH in Acetonitrile), and 1649 (Urban Particulate Matter) are given along with some suggested uses for these SRM's.     

Detectors for Liquid Chromatographic Analysis for Polynuclear Aromatic Hydrocarbons

Abstract

A number of liquid chromatographic detectors of various types have been evaluated for both selectivity and sensitivity for the detection of polynuclear aromatic hydrocarbons (PAH). Detection limits for fixed and variable wavelength UV photometers, filter fluorimeters, and spectrofluorimeters have been determined. The utility of each of these types of detectors for use in the reversed-phase HPLC analysis of environmental extracts containing trace levels of PAH's is discussed.     

Ozone Degradation of Polycyclic Aromatic Hydrocarbons Adsorbed on Asbestos

Abstract

The polycyclic aromatic hydrocarbons (PAH) represent a major source of pollution. The adsorption properties of chrysotile give us a good application as an asbestos filter and the regeneration can be made by ozonolysis for a complete destruction to non toxic compounds.     

Selectivity Factors for Several Pah Pairs on C18 Bonded Phase Columns

Abstract

The selectivity factors for four pairs of polycyclic aromatic hydrocarbons (PAHs) have been found to be very different on the HC-ODS column in comparison to most other C₁₈ bonded-phase columns. The selectivity factors for these PAH pairs varied slightly with different manufacturing lots of the HC-ODS material, the selectivity variations for each PAH pair being linearly correlated with those for the other pairs.     

Electric birefringence of solutions of aromatic poly(amide hydrazide) in dimethyl sulphoxide

Birefringence in a pulsed electric field has been investigated for solutions of para-aromatic polyamid hydrazide (PAH) in dimethyl sulphoxide. The values of the specific Kerr constant K extrapolated to zero concentration have been determined. The experimental data are adequately described by the theoretical dependence of K on the contour length of the PAH molecules for kinetically rigid wormlike chains. The angle formed by the dipole moment of the monomer unit and the direction of the PAH chain was found to be 61.5 ± 1.5°. Comparison between relaxation times obtained from the curves of the decay of birefringence after the end of the electric pulse and the intrinsic viscosities of some PAH samples confirm the conclusion about high kinetic rigidity of PAH macromolecules.     

Polymers from Renewable Resources. Xiv. Interpenetrating Polymer Networks Derived from Castor Oil—Isophorone Diisocyanate-Polyacrylamide: Thermal,Scanning Electron Microscopy,and Xrd Studies

Abstract

A large number of castor oil based polyurethanes were prepared using various diisocyanates such as isophorone diisocyanate varying the NCO/OH ratio. All the polyurethanes were reacted with acrylamide and methacrylamide using ethylene glycol dimethacrylate as crosslinker and benzoyl peroxide as initiator. Thermogravimetric analysis of the polymers were followed using computer analysis method for assigning the kinetic mechanism. The degradation steps have been discussed in the light of kinetic parameters. The SEM of some of the IPNs has been studied and the morphology has been examined. The samples were subjected to wide angle X-ray diffraction analysis. Ruland and Vonk method was used to calculate the degree of crystallinity (X_cr).