Studies of toxaphene in technical standard and extracts of background air samples (Point Petre, Ontario) using multidimensional gas chromatography-electron capture detection (MDGC-ECD)
M. Shoeib et al., Studies of toxaphene in technical standard and extracts of background air samples (Point Petre, Ontario) using multidimensional gas chromatography-electron capture detection (MDGC-ECD), CHEMOSPHERE, 40(2), 2000, pp. 201-211
MDGC-ECD procedures have been used to provide insight into the compositiona
l complexity of some of the specific peaks or clusters observed in the gas
chromatographic analysis of a technical toxaphene standard, with reference
to individual toxaphene congeners (Parlar # components) that are now commer
cially available. These investigations have focussed initially upon those p
eaks and clusters recently identified (Shoeib, M., Brice, K.A.. Hoff, R., 1
999. Chemosphere 39, 849-871) as dominant constituents of background ambien
t air. Multiple electron-capturing components have been found to be present
in all the species studied: the available individual toxaphene congeners h
ave been matched against these components where possible. In similar fashio
n, the responses obtained in equivalent gas chromatographic elution windows
from the analysis of typical processed air sample extracts have been inves
tigated, with the results showing clear differences relative to the pattern
s found in the technical toxaphene standard. In most cases, the air sample
shows reduced complexity with fewer components present in the cluster. Also
, the presence of interfering responses (due to PCBs and other organochlori
nes) is quite apparent and significant, showing that major problems and err
ors could arise when using single-column GC-ECD procedures for quantitation
of toxaphene in environmental samples. The presence of certain of the Parl
ar species in the air samples has been confirmed and in most cases these re
present the dominant toxaphene component found in the targeted cluster. Fur
thermore, the persistence of certain congeners in the atmospheric samples a
ppears to be strongly dependent upon chemical structure, since the congener
s in question possess an alternating exo-endo chlorine substitution pattern
around the six-membered ring in the bornane skeleton. Such persistence is
probably the result of lower metabolization of toxaphene residues in soils,
water and sediments leading to a similar pattern in the atmosphere followi
ng volatilization. (C) 1999 Elsevier Science Ltd. All rights reserved.