This UNITECR 2022 paper is an open access article under the terms of the Creative Commons Attribution License, CC-BY 4.0, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited. COMPARATIVE ANALYTICAL CHARACTERIZATION OF TWO CARBONACEOUS BINDERS USED IN REFRACTORY MATERIALS J. Doll*, A. Masoudi Alavi and P. Quirmbach University of Koblenz-Landau, Germany ABSTRACT The introduction of carbon compounds into refractory materials leads to significant im- provements in technological properties, espe- cially with regard to thermal shock resistance. However, regulations are becoming more strin- gent due to negative impact on human health and the environment. In this context, organic binders such as coal tar pitches containing high levels of polycyclic aromatic hydrocarbons are of particular scientific interest. Despite inten- sive research, their specific chemical composi- tion is still not completely clarified. In this study, two commercial binder systems with dif- ferent softening points used in refractory mate- rials were investigated. For this purpose, a non- target approach was applied. Due to the com- plexity of the samples and the large fractions of semi- and non-volatile compounds, a combina- tion of different analytical methods was ap- plied. In particular, high-resolution time-of- flight mass spectrometry (HR-TOFMS) proved to be a powerful tool for gaining deeper insights into the structure of these samples, such as mo- lecular weight distribution or aromaticity. In addition, further information on the occurrence and distribution of heteroatomic compounds such as S-, N- and O-derivates could be ob- tained. INTRODUCTION Coal tar pitches (CTP) are an important raw material for the production of carbon-con- taining refractory materials. The purpose of carbon is the significant improvement of the materials properties. This includes increased thermal shock resistance due to improved ther- mal conductivity as well as wear reduction due to reduced slag infiltration depth1. While the property-improving character of CTP binders is undisputed, the exact chemical composition re- mains unclear. This is particularly problematic in the context of the increasingly stringent reg- ulations with regard to environmental and health protection. Polycyclic aromatic hydro- carbons (PAH), which have been shown to have carcinogenic and mutagenic properties, are mainly the focus of attention. In this context especially the 16 EPA-PAHs with their lead component benzo[a]pyrene were frequently in- vestigated2. Apart from this, CTP are often classified by their average structures through elemental analysis, by their solubility in or- ganic solvents or their softening points3. Due to their complexity non-target analyses have been performed by a combination of different ana- lytical methods, in particular mass spectrome- try4–6. However, the analysis of pitches is char- acterized by the non-inclusion of heteroatomic compounds which is justified by the small pro- portion of heteroatomic elements6. This is un- satisfying, since the hazard potential of S-, N- and O-derivatized polycyclic aromatic hydro- carbons has been known for a long time and is in no way inferior to that of pure hydrocar- bons7. It was not until 2020 that heteroatomic compounds in solid pitch samples were first considered and analysed by APPI-FT ICR MS and MALDI-FT ICR MS after Soxhlet extrac- tion8. The focus of this work was the sepa- rated analysis of heteroatomic compounds con- taining sulphur, nitrogen and oxygen. For this purpose, two CTP-binders with different sof- tening points were investigated by the applica- tion of different analytical techniques. The