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You searched for +publisher:"ETH Zürich" +contributor:("Heeb, Norbert"). One record found.

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ETH Zürich

1. Schinkel, Lena. New Analytical Methods for Investigating the Fate of Chlorinated Paraffins and Their Transformation Products.

Degree: 2019, ETH Zürich

Chlorinated paraffins (CPs) are industrial chemicals widely applied as plasticizers, flame retardants and additives in metal working fluids. CPs are produced by nonspecific chlorination of it{n}-alkane mixtures. Therefore, they are a complex class of compounds of tens of thousands of different isomers. CPs can differ in carbon chain length (C10-C30) and degree of chlorination (30-70 m/m%Cl}). They are categorized according to their chain length into short-chain (SCCPs, C10-C13), medium-chain (MCCPs, C14-C17) and long-chain CPs (LCCPs, C≥18). CPs are high production volume chemicals (>1000000 t/a) of emerging environmental concern. SCCPs are persistent, bioaccumulative, subject to long-range transport and toxic. In 2017, SCCPs have been listed as persistent organic pollutants (POPs) under the United Nations Stockholm Convention. Due to their complexity, the analysis of CPs is challenging. Several issues are associated with CP analysis, including (a) chromatographic co-elution of the many isomers, (b) unknown composition of CP standard materials, and (c) broad and complex isotopic clusters often resulting in interfered mass spectra. These issues get worse in presence of CP transformation products. Up to now, CP research mainly focused on reporting SCCP levels in different matrices. Only few studies dealt with their environmental toxicity and the identification of transformation pathways and products. Even fewer studies, reported respective data for MCCPs. Almost no studies are available for LCCPs. Risk assessments and discussions about the regulation of CPs are impeded by the many analytical uncertainties and, hence, the lack of robust data. It is crucial that analytical issues are addressed and solved, and comprehensive data about the fate of CP is generated. The focus of this thesis is on the development of new analytical methods to investigate CPs and potential transformation pathways and transformation products. CPs are considered persistent in the environment and, hence, their abiotic and biotic transformation is slow. This thesis considered thermal exposure during the application of CPs as an important transformation pathway and this subject was herein investigated. In the first part of this thesis, thermal transformation products of CPs were identified by mass spectrometric (MS) analysis using thermally aged chlorinated tridecane mixtures. Direct liquid injection coupled to chloride-enhanced atmospheric pressure chemical ionization (APCI) was the method of choice. This method forces the formation of pseudo-molecular chloride-adduct ions without fragmentation and, therefore, is highly suited to investigate CPs and their transformation, when applied in full scan mode. It was found that thermal exposure of CPs causes the elimination of HCl, resulting in chlorinated olefins (COs) with one or more double bonds. Isotope clusters of CP and CO isomers of the same chain length and degree of chlorination strongly interfere even at a moderately high mass resolution of R≈10000. This so called CP/CO problem was… Advisors/Committee Members: McNeill, Kristopher, id_orcid0000-0002-2981-2227, Heeb, Norbert, Schäffer, Andreas.

Subjects/Keywords: info:eu-repo/classification/ddc/500; Natural sciences

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APA (6th Edition):

Schinkel, L. (2019). New Analytical Methods for Investigating the Fate of Chlorinated Paraffins and Their Transformation Products. (Doctoral Dissertation). ETH Zürich. Retrieved from http://hdl.handle.net/20.500.11850/344250

Chicago Manual of Style (16th Edition):

Schinkel, Lena. “New Analytical Methods for Investigating the Fate of Chlorinated Paraffins and Their Transformation Products.” 2019. Doctoral Dissertation, ETH Zürich. Accessed October 21, 2019. http://hdl.handle.net/20.500.11850/344250.

MLA Handbook (7th Edition):

Schinkel, Lena. “New Analytical Methods for Investigating the Fate of Chlorinated Paraffins and Their Transformation Products.” 2019. Web. 21 Oct 2019.

Vancouver:

Schinkel L. New Analytical Methods for Investigating the Fate of Chlorinated Paraffins and Their Transformation Products. [Internet] [Doctoral dissertation]. ETH Zürich; 2019. [cited 2019 Oct 21]. Available from: http://hdl.handle.net/20.500.11850/344250.

Council of Science Editors:

Schinkel L. New Analytical Methods for Investigating the Fate of Chlorinated Paraffins and Their Transformation Products. [Doctoral Dissertation]. ETH Zürich; 2019. Available from: http://hdl.handle.net/20.500.11850/344250

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