88
Water In Ecosystems: A Non Renewable Resource
2
EXPERIMENTAL SECTION
2.1 Samples and sampling sites
14 samples of atmospheric aerosols were taken in the west of Corsica, on the
Mediterranean Sea coast during the spring of 1990. 13 Particulate PARs:
Naphthalene; Anthracene, Phenanthrene, Fluoranthene, Pyrene, Benzo a
Anthracene, Chrysene, Benzo a and e Pyrenes, Benzo band k Fluoranthenes,
Indeno Pyrene, Benzo ghi Perylene and Coronene were identified and measured in
these atmospheric samples.
8 atmospheric aerosol samples and 29 surface snow samples were collected in the
ambient air and on the neve of the ice sheet (the upper 3.5 m) at the Summit
station in central Greenland, during the summer of 1992.
6 atmospheric aerosol samples and 8 surface water or fresh snow samples were
collected in Savoy and Lake Carro situated in the central French Alps (2600m
altitude) during the summer of 1993.
14 pesticides, often used in Europe, were sought: Atrazine, Simazine,
Terbuthylazine, Diuron, Trifluralin, Fenithrothion, Carbaryl, Alachlor, Pendimethalin, Isoproturon, Carbofuran, Malathion, Isoxaben and Fluzilazin.
2.2 Analytical method
The PARs and the pesticides are extracted from the various solid or liquid matrices
(particulate matter, water or snow samples) by liquid-liquid or solid-liquid
extraction, in a Soxhlet, by means of mixtures of polar and nonpolar organic
solvents: dichloromethane/cyclohexane for the PARs and hexane/acetone/benzene
for the pesticides. After purification these extracts are analyzed by gas phase
chromatography with electron capture detection (pesticides) or by inversed phase
RPLC, coupled with UV and fluorimetric detectors (pesticides and PARs).
As has been shown elsewhere, by careful choice detection conditions, the
sensitivity and the selecticity are optimized and analysis of these compounds at
very low concentrations (of the order of 220 pg.m- 3 of air) is possible.
3
RESULTS AND DISCUSSION
3.1 Polycyclic Aromatic Hydrocarbons
Relevant data on PARs are presented in Table I. The range of concentrations and
the average concentration are given for the various sites sampled and the different
periods.
PARs are present in all the atmospheric aerosols: urban, rural, marine and polar
aerosols. The order of magnitude of the concentrations varies considerably: four
orders of magnitude between the total mean concentration (TMC) of the urban
aerosol and of the polar aerosol. In urban dust the TMC is close to 100 ng.m- 3
(Paris), with a very pronounced seasonal variation (factor of to) between summer
and winter periods.
Water In Ecosystems: A Non Renewable Resource
2
EXPERIMENTAL SECTION
2.1 Samples and sampling sites
14 samples of atmospheric aerosols were taken in the west of Corsica, on the
Mediterranean Sea coast during the spring of 1990. 13 Particulate PARs:
Naphthalene; Anthracene, Phenanthrene, Fluoranthene, Pyrene, Benzo a
Anthracene, Chrysene, Benzo a and e Pyrenes, Benzo band k Fluoranthenes,
Indeno Pyrene, Benzo ghi Perylene and Coronene were identified and measured in
these atmospheric samples.
8 atmospheric aerosol samples and 29 surface snow samples were collected in the
ambient air and on the neve of the ice sheet (the upper 3.5 m) at the Summit
station in central Greenland, during the summer of 1992.
6 atmospheric aerosol samples and 8 surface water or fresh snow samples were
collected in Savoy and Lake Carro situated in the central French Alps (2600m
altitude) during the summer of 1993.
14 pesticides, often used in Europe, were sought: Atrazine, Simazine,
Terbuthylazine, Diuron, Trifluralin, Fenithrothion, Carbaryl, Alachlor, Pendimethalin, Isoproturon, Carbofuran, Malathion, Isoxaben and Fluzilazin.
2.2 Analytical method
The PARs and the pesticides are extracted from the various solid or liquid matrices
(particulate matter, water or snow samples) by liquid-liquid or solid-liquid
extraction, in a Soxhlet, by means of mixtures of polar and nonpolar organic
solvents: dichloromethane/cyclohexane for the PARs and hexane/acetone/benzene
for the pesticides. After purification these extracts are analyzed by gas phase
chromatography with electron capture detection (pesticides) or by inversed phase
RPLC, coupled with UV and fluorimetric detectors (pesticides and PARs).
As has been shown elsewhere, by careful choice detection conditions, the
sensitivity and the selecticity are optimized and analysis of these compounds at
very low concentrations (of the order of 220 pg.m- 3 of air) is possible.
3
RESULTS AND DISCUSSION
3.1 Polycyclic Aromatic Hydrocarbons
Relevant data on PARs are presented in Table I. The range of concentrations and
the average concentration are given for the various sites sampled and the different
periods.
PARs are present in all the atmospheric aerosols: urban, rural, marine and polar
aerosols. The order of magnitude of the concentrations varies considerably: four
orders of magnitude between the total mean concentration (TMC) of the urban
aerosol and of the polar aerosol. In urban dust the TMC is close to 100 ng.m- 3
(Paris), with a very pronounced seasonal variation (factor of to) between summer
and winter periods.