209 PCBs: Improved reporting scheme with higher resolution

Improved analytical method for polychlorinated biphenyls

Eurofins has improved the analytical method for the determination of all 209 PCBs. Due to the necessary switch to a different type of gas chromatography (GC) column for the measurement of 209 PCBs, this analytical method has been improved, leading to a lower number of co-eluting PCB-congeners. Thus, more detailed information on concentrations of all 209 PCBs in all types of sample matrices can now be achieved.

Background: PCBs as group of substances

Polychlorinated Biphenyls (PCBs) are a group of persistent organic pollutants (POPs) which consists of 209 individual components (congeners). The congeners differ regarding the number (1 to 10) and position of the chlorine atoms. PCBs were produced on purpose for a variety of different industrial applications. They are extremely stable, both in terms of their chemical and thermal qualities. Due to their very good liposolubility and persistency (biologically nearly non-degradable), they accumulate in fatty tissues of animals and humans along food chains.

With regard to their toxicity, PCBs can be divided into two groups. A group of 12 congeners (non-ortho PCBs and mono-ortho PCBs) shows toxic effects comparable to “dioxins” (PCDD/Fs), they are called dioxin-like PCBs (dl-PCBs or WHO-PCBs). All other PCBs show toxicological properties not comparable to dioxins and are thus called non-dioxin-like PCBs (ndl-PCB = non-dioxin-like PCBs).

Within the group of ndl-PCBs, there are six marker or indicator PCBs (ICES-6) that represent a large proportion (approximately 20-50 %) of the ndl-PCBs. Historically, this total is considered an appropriate marker for the presence of ndl-PCBs and their exposition to humans. For some years now, however, there has been a discussion - especially in the USA - of considering all 209 possible PCB congeners as a whole (“Total PCBs”, “Total 209 PCBs”). This would avoid the uncertainties resulting from the analysis of only single representative substances.

The analysis of all 209 PCBs is a sophisticated one

Only a few laboratories worldwide have the knowledge and experience to perform the analysis of all 209 PCBs. The analytical method of Eurofins covers special demands as e.g.

• Analysis of all PCBs with optional reporting of homologue totals or individual information on all 209 congeners
• Analysis according to US EPA method 1668 and certain legislation demands (e.g. California Proposition 65; GOED limit values)
• Analysis of special sets of single PCB congeners (besides the generally required 12 dioxin-like-PCBs (DL-PCBs, also known as WHO-PCBs) or 6 non-dioxin-like PCBs (NDL-PCBs, also known as indicator- or marker-PCBs or ICES6-PCBs))

The specialized analytical method developed by Eurofins GfA Lab Service for the determination of all 209 PCBs has successfully met these requirements for more than eight years.

New GC-column leads to improvement of analytical method

Specific, highly effective gas chromatographic separation columns are used for the analysis of all 209 PCBs in a variety of matrices. The switch to a new type of separation columns resulted in the need to adapt the previous reporting scheme of the individual PCB congeners. We have taken this opportunity to make every effort to further increase the detail level of information. The improved analytical method is now able to reduce the number of PCBs analysed with co-elution of one or more other PCB congeners and increase the number of individual PCB congeners analysed:

In addition, these current changes show another benefit: The most important PCBs (12 DL and 6 NDL PCBs) can now be reported without co-elution. An exception is PCB 52, which can now be reported as co-elution with only one additional PCB congener (instead of previously two additional PCBs).

More information on the new 209PCB method reporting scheme

If you would like to receive a detailed overview of these changes or ask further questions please do not hesitate to contact our experts for PCBs.