Organic compounds in soils 17
analysis of the polluted soil sample. The upper trace represents a part of the total ion
current magnified eight times. The identification was based on manual comparison
of mass spectra and relative gas chromatographic retention times with literature data
[33, 34] and with data of standards available. In some cases unknown compounds
were tentatively identified on the basis of a priori interpretation of their mass spectra.
Various workers [33, 36] have discussed various aspects of the determination of
total petroleum hydrocarbons and benzene, toluene, ethyl benzene and xylene in soils.
Greco et al [37] determined optimal extraction conditions for the recovery of
nitrogen-containing aromatic compounds from soil.
Solvent extraction with methanolic hydrolysis of the soil has been used to extract
aromatic hydrocarbons. Significantly higher quantities of organics were recovered
compared to the use of only an organic solvent extraction [38].
2.1.3 Polycyclic aromatic hydrocarbons (PAH)
The interest in determining the concentration of polycyclic hydrocarbons in soil is
evidenced by the vast number of publications on this subject over the past decade.
Polycyclic aromatic hydrocarbons represent a class of compounds of great environmental concern due to their suspected mutagenic and carcinogenic properties [39–44].
Unease over the potential adverse health effects of polycyclic aromatic hydrocarbons is
evident in the recent inclusion of 16 polyaromatic hydrocarbons in the Environmental
Protection Agency’s priority contaminates list. Polycyclic aromatic hydrocarbon contaminates pose several potential health risks due to the persistence of these compounds
in the environment [45, 49], the tendency to strongly bind to soil surface [47, 49],
and their presence in a wide variety of common media (air, dust, soil and food) [50].
Possible risks are associated with skin contact, inhalation or ingestion of contaminated
dust, soil, or air, and ingestion of contaminated food,
Environmental polycyclic aromatic hydrocarbon contamination has many different sources. Petroleum-based fuels and oils are known including polycyclic aromatic
hydrocarbon sources with total polycyclic aromatic hydrocarbon contents as high
as 4 wt% for diesel fuel and 5 wt% for gasoline [51]. Pipeline ruptures, tanker
failures, underground and aboveground storage tank leaks, and various other production and transportation accidents frequently produce hydrocarbons-contaminated
soil and groundwater on enormous scales. Therefore, hydrocarbon spills represent a
large and widespread cause of soil and groundwater polycyclic aromatic hydrocarbon contamination. In addition, fossil fuel combustion produces airborne particulate
matter containing polycyclic aromatic hydrocarbons. Petroleum hydrocarbon contamination may also occur naturally though seepage from underground oil and natural
gas reserves. However, the transportation and storage needs for petroleum-based fuels
in highly industrialised nations are the main source of bulk contamination problems.
Various workers have discussed extraction methods for polycyclic aromatic hydrocarbons and peats. These include methods used on Soxhlet extraction [52,53], pressurised liquid extraction [54–56], accelerated solvent extraction [57–60], subcritical
water extraction and supercritical fluid extraction [57–60, 62–71].
Hollender et al [72] and Dreyer et al [73], respectively have carried out recent
studies on different methods and solvents for the extraction of polycyclic aromatic
hydrocarbons.
analysis of the polluted soil sample. The upper trace represents a part of the total ion
current magnified eight times. The identification was based on manual comparison
of mass spectra and relative gas chromatographic retention times with literature data
[33, 34] and with data of standards available. In some cases unknown compounds
were tentatively identified on the basis of a priori interpretation of their mass spectra.
Various workers [33, 36] have discussed various aspects of the determination of
total petroleum hydrocarbons and benzene, toluene, ethyl benzene and xylene in soils.
Greco et al [37] determined optimal extraction conditions for the recovery of
nitrogen-containing aromatic compounds from soil.
Solvent extraction with methanolic hydrolysis of the soil has been used to extract
aromatic hydrocarbons. Significantly higher quantities of organics were recovered
compared to the use of only an organic solvent extraction [38].
2.1.3 Polycyclic aromatic hydrocarbons (PAH)
The interest in determining the concentration of polycyclic hydrocarbons in soil is
evidenced by the vast number of publications on this subject over the past decade.
Polycyclic aromatic hydrocarbons represent a class of compounds of great environmental concern due to their suspected mutagenic and carcinogenic properties [39–44].
Unease over the potential adverse health effects of polycyclic aromatic hydrocarbons is
evident in the recent inclusion of 16 polyaromatic hydrocarbons in the Environmental
Protection Agency’s priority contaminates list. Polycyclic aromatic hydrocarbon contaminates pose several potential health risks due to the persistence of these compounds
in the environment [45, 49], the tendency to strongly bind to soil surface [47, 49],
and their presence in a wide variety of common media (air, dust, soil and food) [50].
Possible risks are associated with skin contact, inhalation or ingestion of contaminated
dust, soil, or air, and ingestion of contaminated food,
Environmental polycyclic aromatic hydrocarbon contamination has many different sources. Petroleum-based fuels and oils are known including polycyclic aromatic
hydrocarbon sources with total polycyclic aromatic hydrocarbon contents as high
as 4 wt% for diesel fuel and 5 wt% for gasoline [51]. Pipeline ruptures, tanker
failures, underground and aboveground storage tank leaks, and various other production and transportation accidents frequently produce hydrocarbons-contaminated
soil and groundwater on enormous scales. Therefore, hydrocarbon spills represent a
large and widespread cause of soil and groundwater polycyclic aromatic hydrocarbon contamination. In addition, fossil fuel combustion produces airborne particulate
matter containing polycyclic aromatic hydrocarbons. Petroleum hydrocarbon contamination may also occur naturally though seepage from underground oil and natural
gas reserves. However, the transportation and storage needs for petroleum-based fuels
in highly industrialised nations are the main source of bulk contamination problems.
Various workers have discussed extraction methods for polycyclic aromatic hydrocarbons and peats. These include methods used on Soxhlet extraction [52,53], pressurised liquid extraction [54–56], accelerated solvent extraction [57–60], subcritical
water extraction and supercritical fluid extraction [57–60, 62–71].
Hollender et al [72] and Dreyer et al [73], respectively have carried out recent
studies on different methods and solvents for the extraction of polycyclic aromatic
hydrocarbons.