GC-ECD大体积进样分析水和土壤中多氯联苯

Environmental legislations approved by federal agencies
like US EPA, or by European Commission Directives [1,2],
aim at the most severe reduction of the PCB levels in
water and soils (< 1 ng/kg in the original sample). This
implies, for a PCB analytical method to be validated, the
achievement of very low detection limits (< 0.5 ng/kg in
the extract).
The identification and quantitation of PCBs is most
often accomplished by gas chromatographic techniques
coupled with Electron Capture Detector (ECD), which has
selective sensitivity to chlorinated compounds. Method
sensitivity can be further amplified using large sample
volume injection into the GC [3]. Among the different
techniques used for large volume injection, the recently
introduced LV-SL [4] has the following advantages: (1) It
is simpler because it allows injections, up to 50 µL, in a
conventional split/splitless injector without any special

tuning of operating parameters, and (2) it is robust when
analyzing sample by-products or contaminants, such as
those found in food matrices or soil extracts. It is also
suitable for the analysis of labile pesticides, and it is
compatible with any GC detector [5].
In this method, the application of Large Volume
Splitless (LV-SL) to GC-ECD is validated for the
determination of polychlorinated biphenyls (PCBs) in soil
and water samples.  GC-ECD analyses of 20-30 µL of (1)
standard Aroclor mixtures and (2) Liquid/Liquid or
Accelerated Solvent Extraction (ASE) extracts of spiked
water/soil matrices are reported. Injections were
performed with the TriPlus Autosampler; GC oven, and
conventional SSL injector conditions were set-up with
dedicated software; the analytical method was validated
through determination of detection limits, linearity,
extraction recoveries, and repeatability.

A 20-30 times more sensitive method than traditional GC-
ECD has been developed and validated for the
determination of PCBs in soil and water. Methods of
analysis were evaluated through determination of
detection limits (down to sub ppb level), quantification
limits (down to few ppb), linearity and repeatability.
Validation was completed by the determination of PCBs
extraction recoveries obtained using Liquid/Liquid and
ASE extraction.
LV-SL has proven to be a reliable tool for trace
analysis in environmental applications, being robust
against “very dirty” samples like soil extracts. LV-SL is the
easiest large volume injection GC technique, since it does
not require any special hardware or tedious tuning of
operating parameters. Full automation is provided
through the dedicated LV-SL Assistant software.