224 Organic compounds in soils, sediments & sludges
screening procedure to detect whether these compounds were present, and a confirmatory method involving formation of the sulphonyl chlorides and subsequent high
resolution gas chromatography with flame ionisation detection and directly coupled
mass spectrometry employing both electron-impact and chemical-ionisation modes.
The linear alkylbenzenesulphonates concentrations found in several digested sludges
ranged from 0.3–1.2% of dry sludge. The implications of these high concentrations
for the use of sludge in agriculture are considered.
Simms et al [60] discuss the quantitative determination of cationic surface active
agents at the sub-ppb level in sewage sludges using fast atom bombardment mass
spectrometry.
High performance liquid chromatography
The technique has been used by various workers to determine linear alkyl benzene
sulphonates in sludges [54, 61, 62, 67].
Sweetman et al [10] used steam distillation followed by HPLC or gas chromatography to determine alkyl benzene sulphonates, n-alkanes, alkyl benzenes, polycyclic
aromatic hydrocarbons and 4-nonyl phenol in sewage sludge.
Spectrophotometry
Hellmann et al [63] shhoed that cationic surfactants of the dialkyldimethyl-ammonium
chloride type may be extracted from sewage sludges by a combination of organic
solvents and concentrated hydrochloric acid. The determination of the surfactant
in the resultant extract by formation of a complex with disulphide blue requires
the separation of anionic and non-ionic surfactants as well as other interfering substances such as humic acids, and dissolved iron and manganese. Methods of purifying
the extract are described together with results of analyses performed on various
sludges. Typical values were between 500 and 1000 ppm with the majority closer to
1000 ppm.
Ambe and Hanya et al [64] combined the Longwell and Maniece et al [65] methods
using methylene blue with the infrared spectroscopic method of Salle [66] to devise a
method for the determination of alkylbenzene sulphonates. Methylene blue alkylbenzene sulphonate complexes give absorption peaks at 800 and 1010 cm
−1 , the ratio of
the heights being proportioned to the ratio of the amounts of sulphonate to the total
amount of methylene blue sensitive substances in the coupling. This method has been
applied to bottom sediments and muds. The dried mud sample was extracted with
benzene-methanol and the extract examined by infrared spectroscopy.
Electron spin resonance spectroscopy
Sevesi and Sposito et al [69] studied copper II-anionic surfactant complexes using
electron spin resonance (ESR) spectrometry. The surfactants used were linear alkyl aryl
sulphonate, sodium dodecyl benzene sulphonate, and sodium lauryl sulphate. Copperligand molar ratios ranged from 0.1 to 10.0 ESR spectra of frozen (77 K) aqueous
solutions showed that all three surfactants formed inner sphere complexes with copper
(II) ions held in four oxygen-legand square planar binding sites. The sulphonate type
surfactants had a higher affinity for copper (II) that did the ester sulphate type. The
copper (II) anionic surfactant complexes were different from, and less stable than,
screening procedure to detect whether these compounds were present, and a confirmatory method involving formation of the sulphonyl chlorides and subsequent high
resolution gas chromatography with flame ionisation detection and directly coupled
mass spectrometry employing both electron-impact and chemical-ionisation modes.
The linear alkylbenzenesulphonates concentrations found in several digested sludges
ranged from 0.3–1.2% of dry sludge. The implications of these high concentrations
for the use of sludge in agriculture are considered.
Simms et al [60] discuss the quantitative determination of cationic surface active
agents at the sub-ppb level in sewage sludges using fast atom bombardment mass
spectrometry.
High performance liquid chromatography
The technique has been used by various workers to determine linear alkyl benzene
sulphonates in sludges [54, 61, 62, 67].
Sweetman et al [10] used steam distillation followed by HPLC or gas chromatography to determine alkyl benzene sulphonates, n-alkanes, alkyl benzenes, polycyclic
aromatic hydrocarbons and 4-nonyl phenol in sewage sludge.
Spectrophotometry
Hellmann et al [63] shhoed that cationic surfactants of the dialkyldimethyl-ammonium
chloride type may be extracted from sewage sludges by a combination of organic
solvents and concentrated hydrochloric acid. The determination of the surfactant
in the resultant extract by formation of a complex with disulphide blue requires
the separation of anionic and non-ionic surfactants as well as other interfering substances such as humic acids, and dissolved iron and manganese. Methods of purifying
the extract are described together with results of analyses performed on various
sludges. Typical values were between 500 and 1000 ppm with the majority closer to
1000 ppm.
Ambe and Hanya et al [64] combined the Longwell and Maniece et al [65] methods
using methylene blue with the infrared spectroscopic method of Salle [66] to devise a
method for the determination of alkylbenzene sulphonates. Methylene blue alkylbenzene sulphonate complexes give absorption peaks at 800 and 1010 cm
−1 , the ratio of
the heights being proportioned to the ratio of the amounts of sulphonate to the total
amount of methylene blue sensitive substances in the coupling. This method has been
applied to bottom sediments and muds. The dried mud sample was extracted with
benzene-methanol and the extract examined by infrared spectroscopy.
Electron spin resonance spectroscopy
Sevesi and Sposito et al [69] studied copper II-anionic surfactant complexes using
electron spin resonance (ESR) spectrometry. The surfactants used were linear alkyl aryl
sulphonate, sodium dodecyl benzene sulphonate, and sodium lauryl sulphate. Copperligand molar ratios ranged from 0.1 to 10.0 ESR spectra of frozen (77 K) aqueous
solutions showed that all three surfactants formed inner sphere complexes with copper
(II) ions held in four oxygen-legand square planar binding sites. The sulphonate type
surfactants had a higher affinity for copper (II) that did the ester sulphate type. The
copper (II) anionic surfactant complexes were different from, and less stable than,