Characterization of synthetic single-chain CP standard materials – Removal of interfering side products

• Published in: Chemosphere (Oxford) Vol. 255; p. 126959
• Main Authors: Heeb, Norbert V., Iten, Silvan, Schinkel, Lena, Knobloch, Marco, Sprengel, Jannik, Lienemann, Peter, Bleiner, Davide, Vetter, Walter
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.09.2020
• Subjects: Chlorinated olefins; Deconvolution; Photolytic chlorination; Sulfite- and sulfate-diesters; Photolytic chlorination; Sulfite- and sulfate-diesters; Deconvolution; Chlorinated olefins
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2020.126959

The photolytic chlorination of n-alkanes in presence of sulfuryl chloride (SO2Cl2) was explored to produce new standard materials. Five mixtures of chlorinated tetradecanes were synthesized with chlorination degrees (mCl,EA) varying from 43.7% to 59.4% (m/m) based on elemental analysis. Chlorine-enhanced negative chemical ionization mass spectrometry (CE–NCI–MS) forcing the formation of chloride-adduct ions [M+Cl]- was applied to characterize these materials which all contained tetra-to deca-chlorinated paraffins. Deconvolution of respective mass spectra revealed the presence of chlorinated olefins (COs). CO levels were highest in materials, which were exposed longest. All synthesized materials also contained two classes of polar impurities, tentatively assigned as sulfite- and sulfate-diesters with molecular formulas of C14H28-xO3SClx (x = 1–4) and C14H28-xO4SClx (x = 3–6), respectively. MS data were in accordance with the proposed structures but further work is needed to deduce their constitutions. These compounds are thermolabile and were not detected with GC-MS methods. We could remove these sulfur-containing impurities from the CPs with normal-phase liquid chromatography. In conclusion, single-chain CP materials were synthesized via chlorination of n-alkanes with sulfuryl chloride, but these materials contained reactive side products which should be removed to gain non-reactive and stable CP materials suitable as standards and for fate and toxicity studies. •Photolytic chlorination on n-alkanes is a versatile route to medium chain CPs.•Synthesis of five chlorinated tetra-decanes with variable chlorination degrees.•Removal of unknown side products resulted in pure MCCP materials.•Side products were removed with normal phase liquid chromatography.•Cyclic sulfite- and sulfate di-esters are in accordance with observed mass spectra.