FormNo. 203-821-244 01/05-REV0
LECO is a registered trademark of LECO Corporation
7
QuantitativeComparisonof GCxGC-ECD andParallel Dual-ColumnGC-ECD
Tables 3 and 4 compare GCxGC-ECD and GC-ECD results for water and soil laboratory control
spikes. These samples were uncontaminatedwithOCPs (and presumably other halogenated
components) previous to the spikes so they represent a good foundation for comparing results.
As can be seen, the concentration values compare nicely between the two techniques.
Table3.
Comparison of GCxGC-ECD and parallel dual-column GC-ECD results (pg/µL) for awater
laboratory control spike extract.
Pesticide
GCxGC-ECD GC-ECD
Tetrachloro-m-xylene
34.7
41.5
alpha-HCH
ND
ND
beta-HCH
ND
ND
gamma-HCH
57.9
58.9
delta-HCH
ND
ND
Heptachlor
54.5
61.7
Aldrin
49.6
62.8
Heptachlor epoxide
ND
ND
gamma-Chlordane
ND
ND
Endosulfan I
ND
ND
alpha-Chlordane
ND
ND
Pesticide
GCxGC-ECD GC-ECD
Dieldrin
115
126
4,4’-DDE
ND
ND
Endrin
116
141
Endosulfan II
ND
ND
4,4’-DDD
ND
ND
Endrin aldehyde
ND
ND
Endosulfan sulfate
ND
ND
4,4’-DDT
110
134
Endrin ketone
ND
ND
Methoxychlor
ND
ND
Decachlorobiphenyl
40.0
41.0
ND= not detected.
Table4.
Comparison of GCxGC-ECD and parallel dual-column GC-ECD results (pg/µL) for a soil
laboratory control spike extract.
Pesticide
GCxGC-ECD GC-ECD
Tetrachloro-m-xylene
31.0
35.8
alpha-HCH
21.6
19.3
beta-HCH
22.3
20.3
gamma-HCH
21.7
19.6
delta-HCH
21.8
19.6
Heptachlor
20.8
19.2
Aldrin
19.0
18.9
Heptachlor epoxide
21.7
18.9
gamma-Chlordane
20.3
18.4
Endosulfan I
19.6
18.1
alpha-Chlordane
19.6
18.7
Pesticide
GCxGC-ECD GC-ECD
Dieldrin
41.9
38.7
4,4’-DDE
40.6
37.1
Endrin
42.3
38.8
Endosulfan II
41.4
38.0
4,4’-DDD
41.4
40.3
Endrin aldehyde
30.3
22.4
Endosulfan sulfate
40.4
43.2
4,4’-DDT
40.0
39.3
Endrin ketone
42.4
43.2
Methoxychlor
195
218
Decachlorobiphenyl
33.7
39.3
ND= not detected.
