142 Organic compounds in soils, sediments & sludges
Carbonyl compounds from particulate material collected on Teflon-coated glassfibre filters were simultaneously extracted and derivatised with an appropriate 2,
4-dinitrophenylhydrazine solution. The efficiency of this procedure utilising various
2,4 dinitrophenyl hydrazine concentrations and solvent compositions was studied for
13 carbonyl compounds of atmospheric importance. These include formaldehyde,
acetaldehyde, acetone, dicarbonyls such as glyoxal and methylglyoxal, and biogenic
carbonyls such as pinonaldehyde and nopinone. An extraction solution containing
3×10
−2 M 2.4 dinitrophenyl hydrazine, in 60% acetonitrile/40% water, and pH 3 was
most efficient in extracting and derivatising these aldehydes and ketones (83–100%
recovery). Improved sample enrichment and 2.4 dinitrophenyl hydrazine purification
methods were developed that afforded detection limits of 0.009–5.6 ng m
−3 . The relative standard deviation for replicate analyses were 1.9–10.1% carbonyl compounds
in ambient particulate samples were quantified in a field study. Median values for nine
carbonyl species ranged from 0.01–33.9 ng m
−3 .
6.2.4 Phthalate esters
Schwartz et al [109] have described a high performance liquid chromatographic
method for determining di-2-ethylhexyl and di-n-butyl phthalate in river sediments.
This method requires no sample clean-up and consists of a single extraction step
followed by quantitative analysis using high performance liquid chromatography. Following this, it is possible to detect down to 10 ng of both esters i.e. equivalent to
0.5 mg kg
−1 .
Thuren et al [18] determined phthalates in sediment using solvent extraction (acetonitrile, petroleum ether), clean-up with deactivated Florisil, and quantitative analysis
by gas chromatography. The detector response was linear between 0.5 and 100 ng. The
detection limit (signal:noise ratio 2:1) was 0.1 ng for dimethyphthalate, dibutylphthalate and di (2-ethylhexyl)phthalate, and 0.05 ng for benzobutylphthalate. Recovery
was between 30% and 130% depending on the ester. Low recovery for dimethylphthalate (30%) was probably due to pyrolysis in the detector (detector temperature
was 320
◦ C).
6.2.5 Cationic detergent
Amber and Hanya et al [51] have combined the Longwell and Maniece et al [52]
methods using methylene blue with the infrared spectroscopic method of Sallee et al
[53] to devise a method for the determination of alkylbenzene sulphonates. Methylene
blue alkylbenzene sulphonate complexes give absorption peaks at 890 and 1010 cm
−1 ,
the ratio of the heights being proportional to the ratio of the amount of sulphonate to
the total amount of methylene blue sensitive substances in the complex.
This method has been applied to bottom sediments and muds. The mud sample is
centrifuged to separate the water, dried at the room temperature, ground and sieved.
This residue is extracted for 1 h at 80
◦ C with methanol-benzene (1:1), the extraction
is repeated twice , and the combined extracts are evaporated and the residue dissolved
in water. Alkylbenzenesulphonates are then determined by infrared spectroscopy as
described above.
Carbonyl compounds from particulate material collected on Teflon-coated glassfibre filters were simultaneously extracted and derivatised with an appropriate 2,
4-dinitrophenylhydrazine solution. The efficiency of this procedure utilising various
2,4 dinitrophenyl hydrazine concentrations and solvent compositions was studied for
13 carbonyl compounds of atmospheric importance. These include formaldehyde,
acetaldehyde, acetone, dicarbonyls such as glyoxal and methylglyoxal, and biogenic
carbonyls such as pinonaldehyde and nopinone. An extraction solution containing
3×10
−2 M 2.4 dinitrophenyl hydrazine, in 60% acetonitrile/40% water, and pH 3 was
most efficient in extracting and derivatising these aldehydes and ketones (83–100%
recovery). Improved sample enrichment and 2.4 dinitrophenyl hydrazine purification
methods were developed that afforded detection limits of 0.009–5.6 ng m
−3 . The relative standard deviation for replicate analyses were 1.9–10.1% carbonyl compounds
in ambient particulate samples were quantified in a field study. Median values for nine
carbonyl species ranged from 0.01–33.9 ng m
−3 .
6.2.4 Phthalate esters
Schwartz et al [109] have described a high performance liquid chromatographic
method for determining di-2-ethylhexyl and di-n-butyl phthalate in river sediments.
This method requires no sample clean-up and consists of a single extraction step
followed by quantitative analysis using high performance liquid chromatography. Following this, it is possible to detect down to 10 ng of both esters i.e. equivalent to
0.5 mg kg
−1 .
Thuren et al [18] determined phthalates in sediment using solvent extraction (acetonitrile, petroleum ether), clean-up with deactivated Florisil, and quantitative analysis
by gas chromatography. The detector response was linear between 0.5 and 100 ng. The
detection limit (signal:noise ratio 2:1) was 0.1 ng for dimethyphthalate, dibutylphthalate and di (2-ethylhexyl)phthalate, and 0.05 ng for benzobutylphthalate. Recovery
was between 30% and 130% depending on the ester. Low recovery for dimethylphthalate (30%) was probably due to pyrolysis in the detector (detector temperature
was 320
◦ C).
6.2.5 Cationic detergent
Amber and Hanya et al [51] have combined the Longwell and Maniece et al [52]
methods using methylene blue with the infrared spectroscopic method of Sallee et al
[53] to devise a method for the determination of alkylbenzene sulphonates. Methylene
blue alkylbenzene sulphonate complexes give absorption peaks at 890 and 1010 cm
−1 ,
the ratio of the heights being proportional to the ratio of the amount of sulphonate to
the total amount of methylene blue sensitive substances in the complex.
This method has been applied to bottom sediments and muds. The mud sample is
centrifuged to separate the water, dried at the room temperature, ground and sieved.
This residue is extracted for 1 h at 80
◦ C with methanol-benzene (1:1), the extraction
is repeated twice , and the combined extracts are evaporated and the residue dissolved
in water. Alkylbenzenesulphonates are then determined by infrared spectroscopy as
described above.