216 Organic compounds in soils, sediments & sludges
based on preliminary thin-layer chromatographic separation and low temperature
spectrophotometric quantification.
Miege et al [13] subjected sewage sludge samples to inmunoafinity solid-phase
extraction for the trace determination of polycyclic aromatic hydrocarbons. Although
recoveries were only 50%, the selectivity of the immune clean-up used resulted in
clean extracts that allowed easier identification and quantitation of polycyclic aromatic
hydrocarbons in sludge.
10.2 OXYGEN CONTAINING COMPOUNDS
10.2.1 Alcohols
Gas chromatography
Fox et al [14] has described a rapid gas chromatographic method for the determination of residual methanol in sewage. In this method the filtered sample is adjusted
to pH 2 and injected directly into the U-shaped stainless steel column packed with
Tenax GC (60–80 mesh) and pre-treated with 85% phosphoric acid for four hours.
For gas chromatography the column was operated at 70
◦ C with nitrogen as carrier gas
(25 ml min
−1 ) and nitrogen flame ionisation detection. The detector response was rectilinear in the range 0.5–199 mg l
−1 of methanol, and for sample containing 50 mg l
−1
of methanol, the coefficient of variation was 2.4%.
Spectrophotometric method
Automated method has been described to determine methanol in denitrified effluents [15]. The method is based on oxidation of methanol to formaldehyde which is
determined colorimetrically after reaction with acetylacetone.
10.2.2 Aldehydes
Gas chromatography
Somiya et al [16] identified and determined products resulting from the ozonization
of secondary effluents. Trace amounts of formaldehyde, acetaldehyde propionaldehyde, methylglyoxylic acid and pyruvic acid were detected by gas chromatography of
their benzyl esters. Formaldehyde methylglyoxal, pyruvic acid and acetic acid were
quantified and their behaviour examined during the reaction.
Spectrophotometric method
Musslewhite and Petts et al [17] have described an automated procedure for the determination of formaldehyde in sewage and sewage effluents. The method is based on the
reaction of formaldehyde with acetylacetone in the presence of excess of an ammonium salt to form a yellow compound, diacetyldihydrolutidine which is determined
colorimetrically.
10.2.3 Carboxylic acids
Gas chromatography
Analysing volatile acids in aqueous systems resulting mainly from the presence of water,
have been reported [18]. The volatile acids’ high polarity as well as their tendency to
based on preliminary thin-layer chromatographic separation and low temperature
spectrophotometric quantification.
Miege et al [13] subjected sewage sludge samples to inmunoafinity solid-phase
extraction for the trace determination of polycyclic aromatic hydrocarbons. Although
recoveries were only 50%, the selectivity of the immune clean-up used resulted in
clean extracts that allowed easier identification and quantitation of polycyclic aromatic
hydrocarbons in sludge.
10.2 OXYGEN CONTAINING COMPOUNDS
10.2.1 Alcohols
Gas chromatography
Fox et al [14] has described a rapid gas chromatographic method for the determination of residual methanol in sewage. In this method the filtered sample is adjusted
to pH 2 and injected directly into the U-shaped stainless steel column packed with
Tenax GC (60–80 mesh) and pre-treated with 85% phosphoric acid for four hours.
For gas chromatography the column was operated at 70
◦ C with nitrogen as carrier gas
(25 ml min
−1 ) and nitrogen flame ionisation detection. The detector response was rectilinear in the range 0.5–199 mg l
−1 of methanol, and for sample containing 50 mg l
−1
of methanol, the coefficient of variation was 2.4%.
Spectrophotometric method
Automated method has been described to determine methanol in denitrified effluents [15]. The method is based on oxidation of methanol to formaldehyde which is
determined colorimetrically after reaction with acetylacetone.
10.2.2 Aldehydes
Gas chromatography
Somiya et al [16] identified and determined products resulting from the ozonization
of secondary effluents. Trace amounts of formaldehyde, acetaldehyde propionaldehyde, methylglyoxylic acid and pyruvic acid were detected by gas chromatography of
their benzyl esters. Formaldehyde methylglyoxal, pyruvic acid and acetic acid were
quantified and their behaviour examined during the reaction.
Spectrophotometric method
Musslewhite and Petts et al [17] have described an automated procedure for the determination of formaldehyde in sewage and sewage effluents. The method is based on the
reaction of formaldehyde with acetylacetone in the presence of excess of an ammonium salt to form a yellow compound, diacetyldihydrolutidine which is determined
colorimetrically.
10.2.3 Carboxylic acids
Gas chromatography
Analysing volatile acids in aqueous systems resulting mainly from the presence of water,
have been reported [18]. The volatile acids’ high polarity as well as their tendency to