Investigation of the structure of chloroparaffins by the nuclear magnetic resonance method

Гусев, М. В.; Urman, Ya.G.; Kocharyan, L. A.; Slonim, I.Ya.

doi:10.1007/bf00907843

Cited by 7 publications

(5 citation statements)

References 10 publications

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“…Although seen most strongly on carbons with geminal chlorines, the effect is also seen on vicinal carbons and their protons although it reduces with distance. The resulting NMR spectra (both 1 H and 13 C) for CPs can be characterised by peaks in the "chlorine-bearing" and "non-chlorinated" ranges (Gusev et al, 1968;Panzel and Ballschmiter, 1974). The information that is present, but not resolvable in these conventional NMR spectra of CP mixtures, can be substantially visualised through two dimensional heteronuclear spectral quantum coherence (HSQC, 1 H-13 C) experiments Yuan et al, 2020;van Mourik et al, 2021) which provide information on the correlations between protons and the carbons to which they are attached.…”

Section: Individual Compound Cp Standardsmentioning

confidence: 99%

Determination of chlorinated paraffins (CPs): Analytical conundrums and the pressing need for reliable and relevant standards

et al. 2022

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Section: Individual Compound Cp Standardsmentioning

confidence: 99%

Determination of chlorinated paraffins (CPs): Analytical conundrums and the pressing need for reliable and relevant standards

et al. 2022

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“…Nuclear magnetic resonance spectroscopy (NMR) analysis of technical CP products 1 H and 13 C NMR spectra 1 H and 13 C NMR spectra of all ten technical CP mixtures showed the known unresolved clusters of multiplets [27][28][29] (Fig. 2, ESM Figs.…”

Section: Gc/ecni-ms Determination Of Chain Length Distribution and Chlorine Content Of Technical Cp Productsmentioning

confidence: 99%

“…Some information about structural elements in technical CP mixtures can be obtained by means of nuclear magnetic resonance spectroscopy (NMR). First 1 H NMR studies on the composition of technical CPs were performed in the 1960s and 1970s [27,28]. However, the low magnetic field strengths of the instruments of these days and the restriction to one-dimensional 1 H NMR experiments prohibited thorough investigations of technical CPs.…”

Section: Introductionmentioning

confidence: 99%

NMR and GC/MS analysis of industrial chloroparaffin mixtures

Sprengel

Vetter

2020

Anal Bioanal Chem

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Chlorinated paraffins (CPs) are high-volume chemicals used worldwide in various industries as plasticizers, lubricants, and flame retardants. CPs are produced by chlorination of alkane mixtures which leads to complex products of thousands of homologs and congeners. Classic mass spectrometric analyses of CPs allow determining carbon chain lengths and degrees of chlorination while information on the substitution patterns cannot be derived. Therefore, we performed different one-and two-dimensional nuclear magnetic resonance spectroscopy (NMR) experiments, elemental analysis (EA), and gas chromatography coupled with electron capture negative ion mass spectrometry (GC/ECNI-MS) for the analysis of ten technical CP products with 42%, 52%, and 70% chlorine content from four producers. Slight differences in chlorine content but varying chain length compositions were observed for similarly labeled products from different manufacturers. Two-dimensional heteronuclear spectral quantum coherence (HSQC) measurements helped to evaluate ten structural elements in the products and confirmed the presence of geminal chlorine atoms in primary and secondary carbons in products with 70% chlorine. The variation of signal groups increased with increasing chlorine content of the products. Two-dimensional heteronuclear multiple bond coherence (HMBC) analysis of one sample and GC/ECNI-MS measurements indicated the presence of impurities (e.g., C 9 -CPs, iso-alkanes) in different technical CP products. These methods could in future allow for better distinction of CP mixtures, and an improved trace-back of environmental CPs to the source, based on specific structural features. Additionally, further structural characterization could help in the development of more accurate analysis processes.

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“…The C 14 -CP standard (Fig. 2a) showed the known distribution of mono-and non-chlorinated signals (Gusev et al, 1968;Sprengel et al, 2019). The monochlorinated peak cluster (labelled A) was smaller than the unchlorinated one (Fig.…”

Section: General Ndingsmentioning

confidence: 97%

“…Quantitative NMR (qNMR) analysis of the rubber ring sample P3. 1 H NMR measurements have been previously used to analyze technical CP mixtures (Gusev et al, 1968;Sprengel and Vetter, 2020;Yuan et al, 2020). The very high MCCP level in sample P3 prompted us to apply qNMR for the analysis of the puri ed sample solution.…”

Section: General Ndingsmentioning

confidence: 99%

Chlorinated paraffins in food contact materials made of rubber from the German market

Vetter

Schulz

Schweizer

et al. 2023

Preprint

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Chlorinated paraffins (CPs), also known as polychlorinated alkanes (PCA), are a very complex class of polyhalogenated compounds currently produced in unmatchable amounts for different industrial uses. Here, we investigated the presence of CPs in 21 rubber samples used as food contact materials from the German market. For this purpose, an analytical method was developed which consisted of (i) freezing and (ii) grounding of the material, (iii) removal of oligomers by adsorption chromatography, (iv) matrix destruction with sulfuric acid, and (v) GC/ECNI-MS screening and quantification. Three of the rubber samples were found to contain predominantly medium-chain CPs (MCCPs; C14- to C17-CPs) at 69, 113,000 and 341,000 mg/kg. The highest amount (corresponding with 34 weight-% CPs) was determined in one rubber band sample used to bundle a bunch of spring onions. A very high CP content of >300,000 mg/kg in this rubber band sample was confirmed by quantitative 1H NMR (qNMR) analysis. This rubber material was in direct contact with the onions and leaching of CPs into the food cannot be excluded. Even more, micro-abrasions of rubber could be unintentionally swallowed by the consumer and this CP exposure could be higher than the current CP intake via food.

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Investigation of the structure of chloroparaffins by the nuclear magnetic resonance method

Cited by 7 publications

References 10 publications

Determination of chlorinated paraffins (CPs): Analytical conundrums and the pressing need for reliable and relevant standards

Determination of chlorinated paraffins (CPs): Analytical conundrums and the pressing need for reliable and relevant standards

NMR and GC/MS analysis of industrial chloroparaffin mixtures

Chlorinated paraffins in food contact materials made of rubber from the German market

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