Water, Air, and Soil Pollution

, Volume 194, Issue 1, pp 151–161

An Improved Gravimetric Method to Determine Total Petroleum Hydrocarbons in Contaminated Soils

  • Mario Villalobos
  • Ana Paulina Avila-Forcada
  • Margarita Eugenia Gutierrez-Ruiz
Article

DOI: 10.1007/s11270-008-9704-1

Cite this article as:
Villalobos, M., Avila-Forcada, A.P. & Gutierrez-Ruiz, M.E. Water Air Soil Pollut (2008) 194: 151. doi:10.1007/s11270-008-9704-1
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Abstract

A gravimetric method to determine heavy fractions of total petroleum hydrocarbons (TPH) in soils is reported. The method was adapted and calibrated by modifying previous standard methods published, incorporating energy and cost savings where possible. Artificially contaminated soils with different organic matter content, and aged in stationary mode for a period of 8 months were used for calibration. Insufficient solvent evaporation was identified as the most prevalent and largest positive interference in the gravimetric detection. To overcome this, while minimizing the need for heating, a combination of three 10-min rotary evaporator steps and 30 min of vacuum in a desiccator were applied, for a total solvent volume of 60 ml. Hexane was chosen as the extraction solvent and a 40–60 min treatment in an ultrasound bath of 260 W was found suitable to extract 80–95% of TPH extracted by the Soxhlet method. Finally, the use of silica gel for cleanup of co-extracted natural organic matter was found unnecessary, because of the low amounts co-extracted for soils with up to 5% organic carbon, and because the chemical nature of the co-extracted organic matter prevents its selective adsorption to silica.

Keywords

Contaminated soilsGravimetric methodSilica gelSolvent evaporationTotal petroleum hydrocarbonsUltrasound extraction

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  • Mario Villalobos
    • 1
  • Ana Paulina Avila-Forcada
    • 2
  • Margarita Eugenia Gutierrez-Ruiz
    • 1
  1. 1.Grupo de Bio-Geoquímica Ambiental, Laboratorio de FisicoQuímica Ambiental (LAFQA) Instituto de GeografíaUniversidad Nacional Autónoma de México (UNAM)CoyoacánMéxico
  2. 2.Dirección General del Centro Nacional de Investigación y Capacitación Ambiental (CENICA), Instituto Nacional de EcologíaSan Rafael Atlixco 186Iztapalapa. D.F.México