Comparison of an Individual Congener Standard and a Technical Mixture for the Quantification of Toxaphene in Environmental Matrices by HRGC/ECNI-HRMS

Abstract

Both a technical standard and a recently commercially available standard containing 25 congeners were used to quantify toxaphene in a variety of environmental matrices, using high-resolution gas chromatography/electron capture negative ion high-resolution mass spectrometry (HRGC/ ECNI-HRMS). The purpose was to examine the differences between the two standards and to assess how well the congener standard describes the total toxaphene profile. At a resolving power of approximately 11,000 no interferences from other organochlorines were observed. Biotic matrices were enriched in octa- and nonachlorobornanes relative to the technical mixture, whereas abiotic matrices were enriched in hexa- and heptachlorobornanes. The hexa- and heptachlorobornanes were generally overestimated by the weighted response of the technical mixture, whereas the nonachlorobornanes were consistently underestimated. The extent to which the technical mixture over- or underestimates total toxaphene concentrations depends on the distribution of congeners among homologue groups and the abundance of particular congeners. The current 25-congener mixture described only approximately 35-75% of the total toxaphene response: more congeners are needed to adequately describe some matrices. Correction factors were developed that will allow laboratories to report reliable concentrations of individual congeners in samples that were quantified using the technical mixture, but they should be applied with caution, as they may be highly instrument dependent.

Anaerobic transformation of compounds of technical toxaphene. 2. Fate of compounds lacking geminal chlorine atoms

“…The 2‐ to 3‐cm depth (1989–1992) showed a nearly complete transformation pattern, and was chosen for further analysis. The extraction and cleanup procedure is described elsewhere [18,19].…”

Non-targeted screening workflows for gas chromatography–high-resolution mass spectrometry analysis and identification of biomagnifying contaminants in biota samples

“…At the base, there is a broad peak of unresolved congeners (this compound class has almost 100,000 possible congeners), which is overlaid by a few highly persistent congeners. Peak picking from top consumer ECNI data allowed some of these compounds to be tentatively identified as B7-1001, B7-1450, B8-1413 (Parlar 26), B8-1412, B8-531/1414/1945, B8-806, B8-2229 (Parlar 44), and B9-1679 (Parlar 50) by comparison to literature data [57,58]. However, the concentrations of these compounds in fish were lower, so the corresponding features were often lost during the data filtering process.…”

Toxaphene trends in the Great Lakes fish

“…Bernardo et al (2005) found that the sum of these three congeners represent 20-50% of total toxaphene in fish oil. The highly variable ratio of individual congeners to total toxaphene suggests that degradation and bioaccumulation of toxaphene differ among species and locations (Braekevelt, et al, 2001;Jantunen and Bidleman, 2003). Batch to batch variability of the technical toxaphene mixture may also contribute to inconsistent Parlar to total toxaphene profiles.…”