Asian Journal of Chemistry and Pharmaceutical Sciences

Open Access Open Access  Restricted Access Subscription Access

Impacts of Extraction Methods and Solvent Systems in the Assessment of Toxic Organic Compounds in a Solid Matrix


Affiliations
  • University of Nigeria, National Center for Energy Research and Development, Nsukka, Nigeria
  • University of Nigeria, Department of Pure and Industrial chemistry, Nsukka, Nigeria
 

Polycyclic Aromatic Hydrocarbons (PAHs) are among the listed persistent organic compounds (POP) which are pollutants of environmental concern due to their toxicity. This study evaluated soxhlet and ultrasonic extraction methods using a three-solvent system (acetone+dichloromethane+n-hexane) in order to compare the ability of the techniques to extract selected PAHs in raw coals collected from a coal mine in Okobo-Enjema, Nigeria. Then, binary solvent mixtures consisting of acetone+dichloromethane; dichloromethane+n-hexane; and acetone+n-hexane, were compared with the ternary solvent system for their ability to extract the target PAHs by soxhlet extraction method. The extracts were quantitatively analysed for sixteen PAHs using Gas Chromatography-Mass Spectrometer (GC-MS). Sonication extraction method extracted higher number of PAHs, required fewer amount of solvents, shorter time of extraction and less energy consumption compared to soxhlet extraction, which extracted higher amount of the target PAHs. The total amount of PAHs determined ranged from 0.02 mg/kg to 0.20 mg/kg in the various solvents' mixtures. The ternary mixture extracted larger quantities of the target toxic PAHs. This report will assist in the choice of analytical methods and solvent systems for environmental studies.

Keywords

Coal, Extraction, PAHs, Solvent Systems, Sonication, Soxhlet
User
Notifications
Font Size

  • Azhari AB. Polycyclic Aromatic Hydrocarbons (PAHs) in air and vegetation: Case study at three selected toll stations along North South Expressway in Johor, Malaysia. Malaysia: UniversitiTun Hussein Onn; 2012.

  • Luch A. The carcinogenic effects of polycyclic aromatic hydrocarbons. London: Imperial College Press; 2005.

  • Zhou HL, Jin BS, Zhong ZP, Huang YJ, Xiao R, Li DJ. Investigation of polycyclic aromatic hydrocarbons from coal gasification. J Environ Sci. 2005; 17(1):141–55.

  • Li F, Jiao H, Dong J, Peng L, Chang L. Study on the PAHs in the Raw Coal Extracts. International Conference on Computer Distributed Control and Intelligent Environmental Monitoring; Changsha. 2011 Feb 19-20. p. 2213–6.

  • Zaugg SD, Bukhardt MR, Burbank TL, Olson MC, Iverson JL, Schroeder MP. Techniques and methods. Wyoming, USA: U S Geological Survey; 2006.

  • Dolinska S, Lovas M, Znamenackova I, Hredzak S, Jakabsky S, Matik M. 11th International Multidisciplinary Scientific Geo Conference SGEM2011, SGEM2011 Conference Proceedings/ ISSN 1314-2704; 2011 Jun 20–25. p. 1083–90.

  • Berkowitz N. An introduction to coal technology. 2nd ed. San Diego, California: Academic Press Inc; 1994.

  • Liu KL, Xie W, Zhao ZB, Pan WP, Riley JT. Investigation of PAHs in fly ash from fluidized bed combustion systems. J Environ Sci Technol. 2000; 34:2273–9.

  • Achten C, Hofmann T. Native Polycyclic Aromatic Hydrocarbons (PAH) in coals- A hardly recognized source of environmental contamination. Sci Total Environ. 2009; 407:2461–73.

  • Stout SA, Emsbo-Mattingly S. Concentration and character of PAHs and other hydrocarbons in coals of varying rank– Implications for environmental studies of soil and sediments containing particulate coal. Org Geochem. 2008; 39(7): 801-19.

  • Willsch H, Radke M. Distribution of polycyclic aromatic compounds in coals of high rank. Polycyc Aromat Comp. 1995; 7:231–51.

  • Jones KC, Seward A, Alcock R, Wilson S. Persistence of organic contaminants in sewage sludge-amended soil: A field experiment. J Environ Qual. 1997; 26:1467–77.

  • Henner P, Schiavon M, Morel JL, Lichtfouse E. Polycyclic Aromatic Hydrocarbon (PAH) occurrence and remediation methods. Analusis. 1997; 25(9-10):M56–9.

  • Mastral AM, Callen MS, Garcia T. Toxic organic emissions from coal combustion. Fuel Process Technol. 2000; 67:1–10.

  • Liu G, Niu Z, Niekerk DV, Xue J, Zheng L. Polycyclic Aromatic Hydrocarbons (PAHs) from coal combustion: emissions, analysis, and toxicology. Rev Environ Contam T. 2000; 192:1–28.

  • Zhang HY, Liu GJ, Xue J. The impact on the species, concentration and distribution of PAHs extracted by different solvents from raw coal. Environ Chem. 2005; 5:613–6.

  • Arditsoglou A, Terzi E, Kalaitzoglou M, Samara C. A comparative study on the recovery of polycyclic aromatic hydrocarbons from fly ash and lignite coal. Environ Sci Pollut R. 2003; 10(6):354–6.

  • Northcott GL, Jones KC. A review of experimental methodologies and analytical techniques for the characterisation of organic compound bound residues in soil and sediment. Environ Pollut. 2000; 108:19–43.

  • Ogala JE, Iwegbue CMA. Occurrence and profile of polycyclic aromatic hydrocarbons in coals and shales from eastern Nigeria. Petroleum and Coal. 2011; 53(3):188–93.

  • Zhao ZB, Liu K, Xie W, Pan WP, Riley JT. Soluble polycyclic aromatic hydrocarbons in raw coals. J Hazard Mater B. 2000; 73:77–85.

  • US EPA. EPA method 3540 C, soxhlet extraction; 1996. Available from: www.3.epa.gov/epawaste/hazard/testmethods/ sw846/pdfs/3540c.pdf

  • US EPA. EPA method 3550, Ultrasonic extraction; 2007. Available from: www.3.epa.gov.3550c.pdf

  • Ragunathan N, Krock KA, Klawun C, Sasaki TA, Wilkins CL. Review, gas chromatography with spectroscopic detectors. J Chromatogr A. 1999; 856:349–97.

  • Speight JG. Handbook of coal analysis. New Jersey, U.S.A: John Wiley and Sons; 2005.


Abstract Views: 393

PDF Views: 193




  • Impacts of Extraction Methods and Solvent Systems in the Assessment of Toxic Organic Compounds in a Solid Matrix

Abstract Views: 393  |  PDF Views: 193

Authors

K. E. Ugwu
, Nigeria
P. O. Ukoha
, Nigeria

Abstract


Polycyclic Aromatic Hydrocarbons (PAHs) are among the listed persistent organic compounds (POP) which are pollutants of environmental concern due to their toxicity. This study evaluated soxhlet and ultrasonic extraction methods using a three-solvent system (acetone+dichloromethane+n-hexane) in order to compare the ability of the techniques to extract selected PAHs in raw coals collected from a coal mine in Okobo-Enjema, Nigeria. Then, binary solvent mixtures consisting of acetone+dichloromethane; dichloromethane+n-hexane; and acetone+n-hexane, were compared with the ternary solvent system for their ability to extract the target PAHs by soxhlet extraction method. The extracts were quantitatively analysed for sixteen PAHs using Gas Chromatography-Mass Spectrometer (GC-MS). Sonication extraction method extracted higher number of PAHs, required fewer amount of solvents, shorter time of extraction and less energy consumption compared to soxhlet extraction, which extracted higher amount of the target PAHs. The total amount of PAHs determined ranged from 0.02 mg/kg to 0.20 mg/kg in the various solvents' mixtures. The ternary mixture extracted larger quantities of the target toxic PAHs. This report will assist in the choice of analytical methods and solvent systems for environmental studies.

Keywords


Coal, Extraction, PAHs, Solvent Systems, Sonication, Soxhlet

References