Chapter 3
Insecticides and herbicides in soils
3.1 CHLORINATED INSECTICIDES
The first step in the determination of insecticides in soils is to efficiently extract the
insecticide from the soil. The insecticide content of the extract can then be determined by methods based, usually, on gas chromatography, preferably linked to a mass
spectrometric detector.
Methods for the extraction of insecticides by supercritical fluid extraction are
reviewed in Table 3.1. Other methods of extraction have, of course, been employed.
Novikova et al [1] has reviewed the literature (209 references) covering the extraction, clean-up and analysis of organochlorine (and organophosphorus) insecticides
in soil. Johnson and Starr et al [2] and Chiba and Morley et al [3] have studied factors affecting the extraction of dieldrin and aldrin from different soil types;
ultrasonic extraction was recommended by these workers. Lopez-Avila et al [4] used
microwave-assisted extraction to extract chlorinated insecticides from soils.
Kimbrough et al [32] recommended the use of polar solvents with Florisil clean-up
for the extraction of organochlorine insecticides from soil.
Hartonen et al [33] have reported various extraction techniques for organochlorine
insecticides in soils. Trapping efficiencies were reported for organochlorine insecticides,
selected polychlorinated benzenes, polybrominated biphenyls and polybrominated
diphenyl ethers.
Steinwandler et al [34] studied several methods for the extraction of HCH
insecticides from soil.
Schwab et al [35] and Chirnside and Ritter et al [36] used extraction with methanol
followed by solid-phase extraction on a C18 cartridge to extract alachlor from soil.
ELISA methods have been used to determine metochlor [194,195], Alachlor and
Alachlor residues in soil [37].
Brady et al [39] have discussed temperature/pressure phase diagrams for carbon
dioxide-DDT and carbon dioxide-polychlorobiphenyls and examined the rate process
of desorption from soils. Supercritical carbon dioxide was used to extract DDT, polychlorobiphenyls and Toxaphene from contaminated soils. Supercritical carbon dioxide
at 100 atm and 40
◦ C was continually passed through a fixed bed of soil. 70% of DDT
and 75% of Toxaphene was leached from a topsoil contained with 1000 mg kg
−1 DDT
and 400 mg kg
−1 supercritical carbon dioxide at a rate of 0.7 g s
−1 .
Insecticides and herbicides in soils
3.1 CHLORINATED INSECTICIDES
The first step in the determination of insecticides in soils is to efficiently extract the
insecticide from the soil. The insecticide content of the extract can then be determined by methods based, usually, on gas chromatography, preferably linked to a mass
spectrometric detector.
Methods for the extraction of insecticides by supercritical fluid extraction are
reviewed in Table 3.1. Other methods of extraction have, of course, been employed.
Novikova et al [1] has reviewed the literature (209 references) covering the extraction, clean-up and analysis of organochlorine (and organophosphorus) insecticides
in soil. Johnson and Starr et al [2] and Chiba and Morley et al [3] have studied factors affecting the extraction of dieldrin and aldrin from different soil types;
ultrasonic extraction was recommended by these workers. Lopez-Avila et al [4] used
microwave-assisted extraction to extract chlorinated insecticides from soils.
Kimbrough et al [32] recommended the use of polar solvents with Florisil clean-up
for the extraction of organochlorine insecticides from soil.
Hartonen et al [33] have reported various extraction techniques for organochlorine
insecticides in soils. Trapping efficiencies were reported for organochlorine insecticides,
selected polychlorinated benzenes, polybrominated biphenyls and polybrominated
diphenyl ethers.
Steinwandler et al [34] studied several methods for the extraction of HCH
insecticides from soil.
Schwab et al [35] and Chirnside and Ritter et al [36] used extraction with methanol
followed by solid-phase extraction on a C18 cartridge to extract alachlor from soil.
ELISA methods have been used to determine metochlor [194,195], Alachlor and
Alachlor residues in soil [37].
Brady et al [39] have discussed temperature/pressure phase diagrams for carbon
dioxide-DDT and carbon dioxide-polychlorobiphenyls and examined the rate process
of desorption from soils. Supercritical carbon dioxide was used to extract DDT, polychlorobiphenyls and Toxaphene from contaminated soils. Supercritical carbon dioxide
at 100 atm and 40
◦ C was continually passed through a fixed bed of soil. 70% of DDT
and 75% of Toxaphene was leached from a topsoil contained with 1000 mg kg
−1 DDT
and 400 mg kg
−1 supercritical carbon dioxide at a rate of 0.7 g s
−1 .