Approaches to the determination of polychlorinated biphenyl (PCB) concentrations in soils/sediments by dechlorination to biphenyl

Citation
Qx. Wu et Wd. Marshall, Approaches to the determination of polychlorinated biphenyl (PCB) concentrations in soils/sediments by dechlorination to biphenyl, INT J ENV A, 80(1), 2001, pp. 27-38
Citations number
23
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Environment/Ecology
Journal title
INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY
ISSN journal
0306-7319 → ACNP
Volume
80
Issue
1
Year of publication
2001
Pages
27 - 38
Database
ISI
SICI code
0306-7319(2001)80:1<27:ATTDOP>2.0.ZU;2-B
Abstract
A method for the dechlorination of PCB mixtures (Aroclor formulations) to b iphenyl was extended to soils. The contaminated sample was mixed with magne sium flakes, potassium hexachloropalladiate (K2PdCl6), propan-2-ol and wate r then permitted to react for up to six hours. Biphenyl, recovered by extra ction into hexane, was quantified by gas chromatography with flame ionizati on detection. The reaction was very efficient in propan-2-ol / water (simil ar to 95%), surfactant emulsion or sand mixture and virtually complete in s oil provided that excess magnesium (2 g) and the K2PdCl6 were added to the sample prior to the addition of water. Higher PCB loadings were readily det ermined in field contaminated soils either by direct determination within t he matrix or by standard additions. However, analyte concentrations were ap preciably over-estimated in Soxhlet or sonication extracts of a certified r eference material that contained sub-ppm levels of analyte. The over-estima tion is considered to result from the conversion in part of natural organic matter to biphenyl.