Organics
103
less than 10 % to the total absorption at 2 925 cm- I . It is desirable, however, that the
nature of the organic matter be determined by means of a study of the complete
infrared spectrum.
Fluorescence spectroscopy has been adapted as an alternative analytical method for
estimating oil in sediments [295,296].
Interlocutory comparisons have been performed on the determination of selected
trace aliphatic and aromatic hydrocarbons in marine sediments [297-299].
4.4.2
Aromatic Hydrocarbons
Hennig [300] has applied ultraviolet spectroscopy to the determination of aromatic
constituents of residual fuel oil in hexane extracts of marine sediment samples.
Examination of the ultraviolet spectra of samples of an oil pollutant from a beach and
crude oil, at various concentrations, revealed strong absorption maxima at approximately 228 nm and 256 nm. The ratio of the peak heights at these wavelengths is
constant for a particular oil, and is independent of concentration. These permit
quantitative analysis of sediment samples many months after an oil spill.
Hargrave and Phillips [301] have used fluorescence spectroscopy to evaluate concentrations of aromatic constituents in aquatic sediments. The oil concerned, a
Venezuelan crude, contained about 35 % by weight of aromatic constituents. Aromatic substances were extracted with n-hexane and fluorescence spectroscopy was used
to produce a series of contour diagrams of fluorescence intensity at various excitation
and emission wavelengths, in order to compare fluorescence spectral patterns of
sample extracts and standard oils. Petroleum residues were determined and it was
found that total oil concentrations ranged from 10 to 3 000 J.Lg g-I wet sediment, with
the highest concentrations occurring in sedimenting particles.
Takada and Ishimatari [302] extracted alkylbenzenes with normal C IO -C I4 and
branched C ll -C l3 alkyl chains from marine and coastal sediment and suspended
matter in benzene methanol. The extract in benzene was then applied to a Florisil
column for removal of copper sulphide and polar materials, and then subjected to
silica gel column chromatography. Alkyl benzenes were quantified and identified
using gas chromatography with flame ionization detection. The recoveries of alkylbenzenes were 81-94 %.
Krahn et al. [303] have described a high performance liquid chromatographic
method for the determination of 127 aromatic hydrocarbons and 21 chlorinated
hydrocarbons in solvent extracts of marine sediments.
4.4.3
Nitrogen-Containing Aromatic Compounds
Krane et al. [304] used capillary column gas chromatography with nitrogen specific
detection and gas chromatography-mass spectrometry to determine nitrogencontaining aromatics originating from creosote oil in solvent extracts of sediments
taken in Eagle Harbour, Puget Sound and in uncontaminated areas. Organic sediment
extracts and the commercial creosote oil were fractionated by silica / alumina column
chromatography. No nitrogen-containing aromatics were detected in sediments from
103
less than 10 % to the total absorption at 2 925 cm- I . It is desirable, however, that the
nature of the organic matter be determined by means of a study of the complete
infrared spectrum.
Fluorescence spectroscopy has been adapted as an alternative analytical method for
estimating oil in sediments [295,296].
Interlocutory comparisons have been performed on the determination of selected
trace aliphatic and aromatic hydrocarbons in marine sediments [297-299].
4.4.2
Aromatic Hydrocarbons
Hennig [300] has applied ultraviolet spectroscopy to the determination of aromatic
constituents of residual fuel oil in hexane extracts of marine sediment samples.
Examination of the ultraviolet spectra of samples of an oil pollutant from a beach and
crude oil, at various concentrations, revealed strong absorption maxima at approximately 228 nm and 256 nm. The ratio of the peak heights at these wavelengths is
constant for a particular oil, and is independent of concentration. These permit
quantitative analysis of sediment samples many months after an oil spill.
Hargrave and Phillips [301] have used fluorescence spectroscopy to evaluate concentrations of aromatic constituents in aquatic sediments. The oil concerned, a
Venezuelan crude, contained about 35 % by weight of aromatic constituents. Aromatic substances were extracted with n-hexane and fluorescence spectroscopy was used
to produce a series of contour diagrams of fluorescence intensity at various excitation
and emission wavelengths, in order to compare fluorescence spectral patterns of
sample extracts and standard oils. Petroleum residues were determined and it was
found that total oil concentrations ranged from 10 to 3 000 J.Lg g-I wet sediment, with
the highest concentrations occurring in sedimenting particles.
Takada and Ishimatari [302] extracted alkylbenzenes with normal C IO -C I4 and
branched C ll -C l3 alkyl chains from marine and coastal sediment and suspended
matter in benzene methanol. The extract in benzene was then applied to a Florisil
column for removal of copper sulphide and polar materials, and then subjected to
silica gel column chromatography. Alkyl benzenes were quantified and identified
using gas chromatography with flame ionization detection. The recoveries of alkylbenzenes were 81-94 %.
Krahn et al. [303] have described a high performance liquid chromatographic
method for the determination of 127 aromatic hydrocarbons and 21 chlorinated
hydrocarbons in solvent extracts of marine sediments.
4.4.3
Nitrogen-Containing Aromatic Compounds
Krane et al. [304] used capillary column gas chromatography with nitrogen specific
detection and gas chromatography-mass spectrometry to determine nitrogencontaining aromatics originating from creosote oil in solvent extracts of sediments
taken in Eagle Harbour, Puget Sound and in uncontaminated areas. Organic sediment
extracts and the commercial creosote oil were fractionated by silica / alumina column
chromatography. No nitrogen-containing aromatics were detected in sediments from