Obiettivo
Chlorobiphenyls (CB) are a class of 209 discrete chemical compounds in which between 1 and 10 chlorine atoms are attached to the biphenyl nucleus. Routine determination of every CB in each sample to be analysed would be prohibitive on a cost of time basis, thus a selection of congeners to be determined was made on the basis of their presence in industrial mixtures, occurrence in a vast number of environmental samples and toxicity. The following CBs were thus chosen: 28, 52, 101, 118, 153 and 180 for certification in a sewage sludge reference material (CRM). Accurate determinations are required for: checking of maximum allowable concentration (MAC values) in raw products and food; identification of pollution sources and for the detection of time trends in environmental pollution.
Because of the difficulty of determining CB congeners, the project started by a study of the various individual steps of the procedure of determination (eg quantification, identification, gas chromatography (GC) separation and GC injection, clean up, concentration and extraction) used by each of the participants. In consecutive collaborative tests these procedures were studied and the sources of error were detected and consequently eliminated. Analytical feasibility studies were conducted with a variety of materials before the contents of sewage sludge was certified.
Chlorobiphenyls (cb's) are a class of 209 discrete chemical compounds in which between one to ten chlorine atoms are attached to the biphenyl nucleus.
The risk to the environment and man of the use of polychlorinated biphenyls (transformer fluids and fluids for hydraulic systems, paper and ink industry, etc.) has for long been underestimated. Large quantities of pcb-mixtures have been produced and are still in use. However, toxicological studies on individual chlorinated biphenyls (cb's) indicate that these compounds are toxic and have both carcinogenic and teratogenic properties in animals.
Since a routine determination of approaching this number of components in each sample to be analysed would be prohibitive on a cost of time basis, a selection of congeners to be determined was made on the basis of their presence in industrial mixtures, occurrence in a vast number of environmental samples and toxicity of the particular congeners; these considerations have also led to legislation in some Member States.
The following cb's (IUPAC-numbers) were thus chosen: 28, 52, 101, 118, 153 and 180 for certification in a sewage sludge RM.
Accurate determinations are required for : checking of MAC-values (MAC = maximum allowable concentration) in raw products and food; identification of pollution sources and for the detection of time trends in environmental pollution.
Campo scientifico
Argomento(i)
Data not availableInvito a presentare proposte
Data not availableMeccanismo di finanziamento
CSC - Cost-sharing contractsCoordinatore
AB11 9DB Aberdeen
Regno Unito