Analysis of polychlorinated dibenzofurans, dioxins and related compounds in environmental samples.

Abstract

The analysis of polychlorinated dibenzofurans (PCDFs), dibenzo-p-dioxins (PCDDs) and to some extent biphenylenes (PCBPs) by high-resolution gas chromatography (HRGC) and mass spectrometry is described. Electron-impact (EI) and negative chemical ionization (NCI) mass spectrometry were used, and their application in environmental analyses documented. NCI shows increased sensitivity to all PCDFs and PCDDs except for 2,3,7,8-and other tetra-CDD isomers. The identification of the various PCDFs and PCDDs, specifically the identification of the toxic and hazardous 2,3,7,8-substituted isomers is emphasized; the unambiguous identification of all 2,3,7,8,-substituted PCDDs is documented. The application of HRGC and mass spectrometry to isomer-specific analyses of samples of aquatic species from the Baltic and the Great Lakes is shown. Results from this and previous studies indicate PCDF and PCDD residues in these organisms including significant levels of 2,3,7,8-substituted isomers. These aquatic species apparently show preferential retention or reduced metabolization rates for these toxic isomers. The results of samples from the Baltic indicate a contamination primarily due to PCDFs. The origin of this contamination seems complex and related to PCBs as well as chlorophenols. PCDF and PCDD isomer distribution patterns from analyses using HRGC and mass spectrometry aid in the identification of origin, sources and elucidation of routes of formation of these compounds. These methods are indispensable in taking measures to reduce future contaminations and to protect our environment.

Genome-Wide Analysis of Salicylate and Dibenzofuran Metabolism in Sphingomonas Wittichii RW1

“…Dibenzofuran (DBF) and dibenzo- p -dioxin (DBD) are poorly water soluble polycyclic aromatic hydrocarbons (PAH) that are formed as byproducts of coal tar industrial processes, during incineration, and in paper pulp bleaching. DBF, DBD, and related compounds with chlorine substitutions are widely present at low concentrations in the environment and the food chain (Bowes et al, 1973 ; Buser et al, 1985 ; Beck et al, 1994 ; Johansen et al, 1996 ), and detrimental effects of exposure have been reported (Zitko et al, 1973 ; Yoshihara et al, 1981 ; McNulty, 1985 ; Pluim et al, 1993 ; Soong and Ling, 1997 ). A number of bacteria can use DBF and DBD as sole carbon and energy sources, including Staphylococcus auriculans (Monna et al, 1993 ), Nocardioides aromaticivorans (Kubota et al, 2005 ), Rhodococcus sp.…”

ToF‐SIMS investigation of ancient ceramics from the Quartaia Site, Tuscany (Italy)

“…The presence of 155, 197 and 219 m / z peaks in US241, FA and TO, but not in CW, confirms our hypothesis. Moreover, these signals seem to be related to the formation of dioxins, polichloro‐bifenils (PCBs) or lactones during the oxidation of lignocellulosic, in burning processes at low temperatures, between 250 and 800 °C 33–45. In particular, the peak at 155 m / z can be related to the presence of 2,6‐dimethoxyphenol,46 the peak at 219 m / z to protonated species of 7‐monochlorodibenzofuran‐1‐olo or dibenzo[b,e][1,4]dioxin, 1‐chloro‐34, 36 and the small signal at 169 m / z to the presence of trimethoxybenzene.…”

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“…The two approaches that best fulfil these requirements are GC-electron capture negative ionization-mass spectrometry (GC-ECNI-MS) and GC-high resolution mass spectrometry (GC-HRMS) (Covaci et al, 2003;de Boer and Wells, 2006;. Brominated substances are often analysed under chemical ionization conditions, monitoring the negative ions formed by electron capture reactions (ECNI) (Buser et al, 1985). The predominant ions formed from organobromine substances under such conditions are the bromine isotopes m/z 79 and 81.…”

“…PBDE levels in human milk over time Meironyté et al (1999) were the first to show an increasing trend of PBDE concentrations in human milk between 1972. Pooled samples from 1972, 1980, 1984/1985 contained concentrations for the sum of the eight PBDE congeners BDE-28, -47, -66, -85, -99, -100, -153 and -154 of 0.07, 0.35, 0.48, 0.73, 1.21, 2.17, 3.11 and 4.02 ng/g fat. Thus, the concentration of PBDEs in Swedish human milk almost doubled every 4 years.…”