Polynuclear Aromatic Hydrocarbons In Water Research Articles

On-line HPLC/SPME Interface using dynamic extraction

This study describes the determination of Polynuclear aromatic hydrocarbons in water using a new modification for the commercial SPME-HPLC interface which incorporates a dynamic SPME-HPLC extraction and vibration in the desorption chamber during the extraction and desorption steps. Extraction and desorption parameters were investigated using fourteen PAHs of different volatilities (naphthalene, acenaphthalene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene) as test compounds and fluorimetric detection. Regression coefficients close to 0.99 with RSD < 8.1% and detection limits in the range 0.004-0.59 µg/L were found. A method was applied to determine the above PAHs in water samples. The results were compared with the 550.1 EPA method at the 0.05 significance level.

Determination of Polynuclear Aromatic Hydrocarbons in Water and Sediment of River Benue in Makurdi Metropolis, Nigeria

Determination of Polynuclear Aromatic Hydrocarbons in Water and Sediment of River Benue in Makurdi Metropolis, Nigeria

Source determination of polynuclear aromatic hydrocarbons in water and sediment of a creek in the Niger Delta region

Polynuclear aromatic hydrocarbons in surface water and sediment of Ekpan Creek of the Warri River were determined with GC Perkin-Elmer/Clarius 500. Compositional patterns of the PAHs were used to distinguish their sources in the aquatic system. The three diagnostic selected concentration ratios of polynuclear aromatic hydrocarbon isomer pairs confirmed that the PAHs concentrations in sediment of Ekpan Creek were from pyrogenic origin and include phenanthrene, anthracene, fluoranthene, pyrene, chrysene and benzo(a)anthracene.

Application of SPME in the Analysis of Polynuclear Aromatic Hydrocarbons in Water by HPLC with DAD Detection

Determination of polynuclear aromatic hydrocarbons is very important in many laboratories of water quality control. The new Council Directive 98/78/EC states that water intended for human consumption shall be monitored on these parameters and meet the parametric values set out in Annex I (less than 0,10 μg/L for the sum of the concentrations of the specified compounds). The usual methodology of such analysis is based on liquid-liquid extraction followed by evaporation/concentration and clean-up steps. The coupling of Solid Phase Microextraction (SPME), a recent sample preparation technique to HPLC and fluorescence or diode-array detection (DAD) is extremely favourable for these compounds, with the aim to reduce the solvent usage and to simplify the procedure. This technique has been applied to the analysis of the following PAHs: fluoranthene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, benzo[ghi]perylene and indeno[1,2,3-cd]pyrene in model aqueous solutions. In this study we describe the optimisation of SPME-HPLC in the analysis of these compounds. The results obtained suggest that this method can be an alternative to the other sample preparation methods already used in this field.

Calibration bias in the determination of polynuclear aromatic hydrocarbons in water

We present the results of an investigative interlaboratory test to determine the reasons for poor agreement between data from different laboratories for the determination of polynuclear aromatic hydrocarbons in water.

Fenton reagent advanced oxidation of polynuclear aromatic hydrocarbons in water

Aqueous oxidation of three polynuclear aromatic hydrocarbons, fluorene, phenanthrene and acenaphthene with the combination of hydrogen peroxide and ferrous ion, Fenton reagent, has been studied. The effect of variables such as concentration of both reactants, pH and presence of bicarbonate ion and humic substances has been investigated. Products resulting from oxidation have also been identified. From experimental results and kinetic data determined the process is confirmed as an advanced oxidation involving the generation of hydroxyl radicals. Oxidation rates are even higher than those from other advanced oxidation systems involving ozone, UV radiation and hydrogen peroxide. Reactivity is in the following decreasing order: Phenanthrene > Fluorene > Acenaphthene.

Oxidation of Polynuclear Aromatic Hydrocarbons in Water. 4. Ozone Combined with Hydrogen Peroxide

Three polynuclear aromatic hydrocarbons, fluorene, phenanthrene, and acenaphthene, have been treated in water with ozone combined with hydrogen peroxide. The effect of hydrogen peroxide concentration, pH, and bicarbonate ions has been investigated. The process goes through direct and radical reactions in the case of fluorene and phenanthrene oxidation, while acenapthene is removed exclusively by direct ozonation. At concentrations of hydrogen peroxide higher than 10-5 M, ozone mass transfer controls the process rate, regardless of pH. In any case, however, the presence of hydrogen peroxide does not improve the oxidation rate compared to ozonation alone due to the importance of the direct reactions. Intermediate compounds identified during oxidation with ozone alone and combined with UV radiation or hydrogen peroxide are similar and justify the high consumption of ozone in these processes.

Oxidation of Polynuclear Aromatic Hydrocarbons in Water. 3. UV Radiation Combined with Hydrogen Peroxide

Oxidation in water of three polynuclear aromatic hydrocarbons (PAHs), fluorene, phenanthrene, and acenaphthene, with UV radiation combined with hydrogen peroxide has been studied. The effect of hydrogen peroxide concentration, pH, and bicarbonate ion has been investigated. Disappearance rates of PAHs are substantially increased with respect to those from UV radiation alone if proper conditions of hydrogen peroxide concentration and pH are established. Direct photolysis contribution decreases with the increasing hydrogen peroxide concentration and is the main way of degradation at acid pH (76% at pH 2 with 10-3 M hydrogen peroxide concentration, for fluorene oxidation). Rate constants of reactions between the hydroxyl radical and PAHs were found to be 9.9 × 109, 8.8 × 109, and 13.4 × 109 M-1 s-1, for fluorene, acenaphthene, and phenanthrene, respectively. Both UV radiation and UV/H2O2 oxidation of PAHs yield numerous intermediate compounds. Most of these compounds disappear as oxidation time is increased.

Oxidation of Polynuclear Aromatic Hydrocarbons in Water. 2. UV Radiation and Ozonation in the Presence of UV Radiation

Direct photolysis with UV radiation (254 nm) and oxidation with ozone combined with UV radiation of three polynuclear aromatic hydrocarbons, fluorene, phenanthrene, and acenaphthene, has been studied. Quantum yields of the direct photolysis of the PAHs determined were 7.5 {times} 10{sup {minus}3}, 6.9 {times} 10{sup {minus}3}, and 52 {times} 10{sup {minus}3} mol(photon){sup {minus}1} for fluorene, phenanthrene, and acenaphthene, respectively. Contributions of direct ozonation, direct photolysis, and radical oxidation have also been estimated for the oxidation with ozone combined with UV radiation. Fluorene is oxidized by direct photolysis and radical reactions, phenanthrene through direct mechanisms, ozonation, and photolysis, and acenaphthene mainly by direct ozonation.

Automated precolumn concentration and high-performance liquid chromatographic analysis of polynuclear aromatic hydrocarbons in water using a single pump and a single valve

The analysis of polynuclear aromatic hydrocarbons (PAHs) has been widely practiced using liquid-liquid extraction as a method of sample clean-up and sample enrichment. For the analysis of PAHs by HPLC, alternative sample preparation methods using solid-phase extraction or precolumn concentration have been reported. These methods normally required a switching valve and/or pump in addition to the HPLC system. This study reports a precolumn concentration method using no additional valve or pump to the HPLC system. The method is evaluated for recoveries, reproducibilities, linearity and minimum detection limits.

Potential of micelle-mediate procedures in the sample preparation steps for the determination of polynuclear aromatic hydrocarbons in waters

The analytical potential of using micelle-mediated procedures for the sampling and preconcentration of polynuclear aromatic hydrocarbons (PAHs) in water was investigated. The effect of micellar systems on the stability of several PAH-containing water samples, stored in different container materials, were studied. It was found that the presence of micelles in the sample was as effective as acetonitrile at a concentration of 40% (v/v) in preventing loss of PAHs due to adsorption on the surface of PTFE or borosilicate glass containers. In addition, the usefulness of such micellar systems for extraction and preconcentration was demonstrated by the observed increase in the recovery of PAHs from waters containing micelles on a typical C 18 cartridge. The possible advantages of micelles over organic solvents for sampling and preconcentration of PAHs in water-borne environmental samples is also discussed.

Determination of polynuclear aromatic hydrocarbons in water by flotation enrichment and HPLC

A method of concentration and determination of several polynuclear aromatic hydrocarbons (PAHs) in water by flotation enrichment and HPLC is described. Triton X-100 was used as the foaming agent to extract the PAHs from water by passage of nitrogen. Reversed-phase liquid chromatography with coupled fluorescence detection was applied to separate and determine these PAHs. Various factors which may affect the recovery of PAHs from water, including pH, temperature and the concentration of Triton X-100 added, are discussed. This simplified method of concentrating PAHs from water has been applied to determine PAHs in water from Lake Erie. The method has practical value for the determination of PAHs in large volumes of water.

Sample enrichment for gas chromatographic—mass spectrometric analysis of polynuclear aromatic hydrocarbons in water and in organic mixtures

The properties of different kinds of graphitized carbon black as traps for the extraction and preconcentration of polynuclear aromatic hydrocarbons from water and mineral oil have been investigated. The best results are obtained with Carbopack F, eluted with toluene at 100°C. Graphitized carbon black is preferred because of its thermal and chemical stability and its high purity.

A review of occurrences and treatment of polynuclear aromatic hydrocarbons in water

The scope of PAH contamination of raw, finished, and distributed waters is reviewed. The concentrations of PAHs in drinking water sources range from nanogram to microgram-per-liter quantities. Conventional treatment (flocculation, sedimentation, chlorination, and filtration) appears to substantially reduce total PAH concentrations present at higher concentrations in source waters. A major factor in this reduction is the removal of PAHs adsorbed onto particulate matter. The role of chlorination is not clear and reactions of PAHs with chlorine may in fact produce products which themselves are deleterious. Activated carbon can further assist in PAH removal. However, it may be inappropriate for treatment of PAHs present at low concentrations. Water entering the distribution system can become recontaminated via contact with reservoirs and pipes coated with coal-tar or asphalt based products.

Monitoring of polynuclear aromatic hydrocarbons in water. II. Extraction and recovery of six representative compounds with polyurethane foams

Monitoring of polynuclear aromatic hydrocarbons in water. II. Extraction and recovery of six representative compounds with polyurethane foams

Monitoring of polynuclear aromatic hydrocarbons in water. I. Extraction and recovery of benzo(a)pyrene with porous polyurethane foam

The concentration of trace quantities of benzo(a)pyrene from water with flexible polyurethane foam plug was studied. The recovery from water was independent of flow rates over a wide range but increased to a great extent with increase in temperature of water. Other factors which influenced benzo(a)pyrene retention were: water pH, diameter of the column used for holding plugs, and coating of the foam plugs with chromatographic phases. The foal-sorbed benzo(a)pyrene was stable, and its recovery quantitative after storage of the plug for seven days at 4/sup 0/C. Some loss of benzo(a)pyrene occurred when foam plugs were stored at room temperature.

Effect of water chlorination upon levels of some polynuclear aromatic hydrocarbons in water

Download Hi-Res ImageDownload to MS-PowerPointCite This:Environ. Sci. Technol. 1976, 10, 12, 1151-1156

Factors affecting the extraction and analysis of polynuclear aromatic hydrocarbons in water

Factors expected to affect the efficiency of extraction of Polynuclear Aromatic Hydrocarbons (P.A.H.) from environmental water samples have been systematically investigated. Such factors include the initial concentration of P.A.H., the presence of suspended solids and prolonged storage of the sample prior to analysis. Extraction efficiencies between 30 and 85% have been found and these data make possible more accurate measurements of levels of P.A.H. in water. Analyses of environmental water samples have been performed using both Thin layer chromatography (TLC) and Gas-liquid chromatography (GLC). Accuracy of analysis was assessed by addition of P.A.H. to environmental water samples before extraction. Thin layer chromatography was found to be the better procedure for the compounds analysed, and avoided the need for purification of the solvent extract prior to analysis.

A determination of polynuclear aromatic hydrocarbons in water by mass fragmentography

A determination of polynuclear aromatic hydrocarbons in water by mass fragmentography