A comprehensive approach to actual polychlorinated biphenyls environmental contamination

Abstract

Worldwide polychlorinated biphenyls (PCBs) pollution is due to complex mixtures with high number of congeners, making the determination of total PCBs in the environment an open challenge. Because the bulk of PCBs production was made of Aroclor mixtures, this analysis is usually faced by the empirical mixture identification via visual inspection of the chromatogram. However, the identification reliability is questionable, as patterns in real samples are strongly affected by the frequent occurrence of more than one mixture. Our approach is based on the determination of a limited number of congeners chosen to enable objective criteria for Aroclor identification, summing up the advantages of congener-specific analysis with the ones of total PCBs determination. A quantitative relationship is established between congeners and any single mixture, or mixtures combination, leading to the identification of the actual contamination composition. The approach, due to its generality, allows the use of different sets of congeners and any technical mixture, including the non-Aroclor ones. The results confirm that PCB environmental pollution in northern Italy is based on Aroclor. Our methodology represents an important tool to understand the source and fate of the PCBs contamination.

Extensive study on physicochemical properties of polychlorinated biphenyls in a commercial ion trap mass spectrometer, relevance in analytical and environmental chemistry

“…Finally, concerning dioxin‐like congeners, a subclass of mono/non ortho PCBs, literature shows that their concentrations in contamination sources and in animals are correlated . However, some other literature shows that dioxin‐like PCB, with the exception of PCB 118, concentration values in animals are significantly higher than in related contamination sources; our results support this last thesis.…”

Signal Processing Methods to Interpret Polychlorinated Biphenyls in Airborne Samples

“…This enables robust joint and compound-cognizant interpretation of target and nontarget peaks from the raw signal. 2) IDENTIFYING SOURCES -Analysis to identify sources can be done using linear regression models [9]- [13] or even positive matrix factorization (PMF) [10]- [13], [52]- [55]. These algorithms attempt to solve for the various percentages of sources through linear equations.…”

“…The choice of k was determined based on empirical observations and the elbow method (see Appendix B). The k-means objective function minimized is shown in (10).…”

“…Geographical locations can have different sources of PCBs thus it is imperative to identify and localize these sources using different techniques. Previously, sources have been identified by either using linear regression models [9]- [13] or even PMF [10]- [13], [52]- [55] on other data sets. In this work, sources are identified by correcting the mass of each PCB congener using the calibration solutions, RRF, and surrogate standard recoveries for each sample, then finding the mass fraction of the PCB congeners in each sample.…”

A consideration of polychlorinated biphenyls as a chemostratigraphic marker of the Anthropocene

“…Each congener may contain up to 10 chlorine atoms. A characteristic feature of PCBs is that these compounds always occur in mixtures, both in technical products and in the environment, but usually, for practical reasons, only selected congeners are determined in environmental samples (Risso et al, 2016). The Stockholm Convention on Persistent Organic Pollutants, recommend that the six most abundant congeners (numbers 28, 52, 101, 138, 153 and 180) should be measured (IARC, 2016) while the International Council for the Exploration of the Sea, recommend reporting these six congeners plus the mono-ortho congener PCB-118.…”