TY - JOUR

T1 - Investigation of source apportioning for α-HCH using enantioselective analysis

AU - Covaci, Adrian

AU - Gheorghe, Adriana

AU - Meijer, Sandra

AU - Jaward, Foday

AU - Jantunen, Liisa

AU - Neels, Hugo

AU - Jones, Kevin C.

PY - 2010/5/1

Y1 - 2010/5/1

N2 - Enantiomeric analysis can be used as a complementary tool for source apportionment of chiral compounds, particularly for α-HCH. In this study we used archived samples from studies related to the distribution of POPs in air-water and air-soil-grass systems. Such approach is based on the behaviour of chiral compounds released into the atmosphere from a primary source, when they are expected to show racemic or close to racemic composition. Contrarily, when chiral compounds have been reemitted from secondary sources (e.g. water or soil), their enantiomeric signatures are frequently non-racemic and are similar to the signature of the secondary source. To show such evidence, extracts from passive air samples deployed throughout Europe were analyzed for the enantiomers of α-HCH. The proximity to a large water body showed a high impact on the enantiomeric signatures: Baltic air had enantiomeric fractions (EFs) <0.500, while Mediterranean air had predominantly EFs >0.500. Similarly, Atlantic air showed a latitude influence: above 50°N most EFs <0.500, whereas at latitudes below 50°N, EFs were >0.500. A similar trend was also observed for EFs of α-HCH measured in air samples from a latitudinal transect during an Atlantic cruise. This transect shows that samples from higher latitudes (above 40°N) have EF <0.500, whereas in the more southern samples (African coast and Southern Atlantic), there is no clear trend for EFs. Inland air samples showed a large range in EF values, with racemic signatures for samples with the highest α-HCH concentrations and an increasing spread in the EFs for lower α-HCH concentrations. As expected, the EF values of α-HCH in air, soils and grass were also impacted by latitude. Correlations between EFs and geographic characteristics of the sampling locations, as well as α-HCH concentrations, α-/γ-isomer ratios, or temperature suggest that enantioselective analysis can give additional information on the distribution and sources of α-HCH in the environment.

AB - Enantiomeric analysis can be used as a complementary tool for source apportionment of chiral compounds, particularly for α-HCH. In this study we used archived samples from studies related to the distribution of POPs in air-water and air-soil-grass systems. Such approach is based on the behaviour of chiral compounds released into the atmosphere from a primary source, when they are expected to show racemic or close to racemic composition. Contrarily, when chiral compounds have been reemitted from secondary sources (e.g. water or soil), their enantiomeric signatures are frequently non-racemic and are similar to the signature of the secondary source. To show such evidence, extracts from passive air samples deployed throughout Europe were analyzed for the enantiomers of α-HCH. The proximity to a large water body showed a high impact on the enantiomeric signatures: Baltic air had enantiomeric fractions (EFs) <0.500, while Mediterranean air had predominantly EFs >0.500. Similarly, Atlantic air showed a latitude influence: above 50°N most EFs <0.500, whereas at latitudes below 50°N, EFs were >0.500. A similar trend was also observed for EFs of α-HCH measured in air samples from a latitudinal transect during an Atlantic cruise. This transect shows that samples from higher latitudes (above 40°N) have EF <0.500, whereas in the more southern samples (African coast and Southern Atlantic), there is no clear trend for EFs. Inland air samples showed a large range in EF values, with racemic signatures for samples with the highest α-HCH concentrations and an increasing spread in the EFs for lower α-HCH concentrations. As expected, the EF values of α-HCH in air, soils and grass were also impacted by latitude. Correlations between EFs and geographic characteristics of the sampling locations, as well as α-HCH concentrations, α-/γ-isomer ratios, or temperature suggest that enantioselective analysis can give additional information on the distribution and sources of α-HCH in the environment.

KW - Air

KW - Alpha-HCH

KW - Enantiomers

KW - Grass

KW - Passive samplers

KW - Soil

KW - Source apportionment

U2 - 10.1016/j.envint.2010.01.003

DO - 10.1016/j.envint.2010.01.003

M3 - Journal article

AN - SCOPUS:77951025714

VL - 36

SP - 316

EP - 322

JO - Environment International

JF - Environment International

SN - 0160-4120

IS - 4

ER -