About Us | Help Videos | Contact Us | Subscriptions



This article in JEQ

  1. Vol. 32 No. 2, p. 571-582
    Received: Aug 2, 2001

    * Corresponding author(s): gnorthcott@hortresearch.co.nz
Request Permissions


Validation of Procedures to Quantify Nonextractable Polycyclic Aromatic Hydrocarbon Residues in Soil

  1. Grant L. Northcott *a and
  2. Kevin C. Jonesb
  1. a HortResearch, East Street, Private Bag 3123, Hamilton, New Zealand
    b Dep. of Environmental Science, Institute of Environmental and Natural Sciences, Lancaster Univ., Lancaster, LA1 4YQ, United Kingdom


This study was conducted to optimize butanol solvent shake extraction, dichloromethane soxtec extraction, and methanolic saponification extraction for the selective extraction of aged polycyclic aromatic hydrocarbons from soil. Extraction kinetics for these methods was established to determine the optimal time necessary to achieve exhaustive compound extraction. This resulted in times of 12, 6, and 5 h, respectively, for butanol, dichloromethane, and saponification, to extract polycyclic aromatic hydrocarbons from previously spiked, then aged soil. Increasing the soil mass to butanol volume ratio reduced the proportion of polycyclic aromatic hydrocarbon extracted by butanol, highlighting the importance of determining and maintaining a constant soil to solvent ratio for comparative purposes. Drying soil samples before dichloromethane soxtec extraction reduced by 30 to 76% the amount of polycyclic aromatic hydrocarbons extracted. The effect of sample drying is discussed with relevance to enhancing the formation of nonextractable compounds in soil and compound losses previously assumed by volatilization. The optimized extraction procedures provided low variability with relative standard deviations ≤ 5.2% for analysis of multiple replicates. The results obtained by the optimized procedures provided equivalent or improved reproducibility to those obtained by other methods reported in the literature.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © 2003. American Society of Agronomy, Crop Science Society of America, Soil Science SocietyPublished in J. Environ. Qual.32:571–582.