Thermal desorption and pyrolysis of various heavy oils and asphaltenes (precipitated with different paraffinic solvents) were studied. For this purpose evolved gas analysis was realized by hyphenation of a thermobalance to ultrahigh-resolution mass spectrometry (FT-ICR MS). The chemical pattern was preserved by applying soft atmospheric pressure chemical ionization (APCI). Collision induced dissociation (CID) was performed for deeper structural insights. Viscous or solid petroleum samples and fractions can be easily measured by the setup. The SARA fractions (maltenes, C7-asphaltenes, aromatics, saturated, and resins), deployed for evaluation purposes, revealed a very complex molecular pattern, and fractionation drastically increased the number of assigned elemental compositions. Species from m/z 150 to m/z 700 and two main phases (desorption and pyrolysis), which transits at roughly 300–350 °C, are observed. Both phases overlap partially but can be separated by applying matrix factorization. The heavy oil and asphaltene mass spectra are dominated by CH-, CHS-, and CHN-class compounds, whereas for the CID spectra a lower abundance of oxygenated species was found. Furthermore, physicochemical properties and the molecular response were correlated for the heavy oils and asphaltene samples, finding a strong correlation between sulfur content and abundance of CHS_x-class compounds as well as between double bond equivalent (DBE) and API gravity. As the CID leads mainly to dealkylation, the length of alkylated side chains of components evolved thermally or by pyrolytic processes can be traced during the temperature ramp. In general, an increase of dealkylation in the desorption phase, followed by a decrease during the transition to pyrolysis and an increase reaching a stable plateau for stable pyrolysis, was detected. This behavior was found to be similar for all asphaltenes and for the mean DBE progression. Deploying a lighter paraffinic solvent for asphaltene precipitation causes a higher abundance of species emitted in the desorption phase. They belong mainly to CHO_x-class compounds from the maltene fraction occluded and coprecipitated with the asphaltenes. Besides this, no significant effect of the precipitation solvent on the asphaltenic core structures and molecular pattern in the pyrolysis phase was observed. The DBE distribution suggests the presence of the archipelago asphaltene molecular architecture.

中文翻译：

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热分析与超高分辨率质谱结合碰撞诱导解离复杂的石油样品：重油组成和沥青质沉淀作用

研究了各种重油和沥青质（用不同的链烷烃溶剂沉淀）的热脱附和热解。为此，通过将热天平连接到超高分辨率质谱仪（FT-ICR MS），实现了析出的气体分析。通过应用软性大气压化学电离（APCI）可以保留化学图案。进行碰撞诱导解离（CID）以获取更深的结构见解。通过该装置可以轻松测量粘性或固态石油样品和馏分。用于评估目的的SARA馏分（麦芽糖，C7沥青，芳烃，饱和和树脂）显示出非常复杂的分子模式，而馏分则大大增加了指定元素组成的数量。来自m / z的物种观察到150至m / z 700和两个主要相（解吸和热解），它们在大约300-350°C的温度下转变。这两个阶段部分重叠，但可以通过应用矩阵分解来分离。重油和沥青质的质谱以CH-，CHS-和CHN类化合物为主，而对于CID谱，则发现了较低的氧化物种。此外，重油和沥青质样品的理化性质和分子响应相关，发现硫含量与CHS _x丰度之间有很强的相关性。类化合物以及双键当量（DBE）和API重力之间的化合物。由于CID主要导致脱烷基，因此可以在温度上升过程中追踪通过热或热解过程产生的组分的烷基化侧链的长度。通常，检测到解吸相中脱烷基的增加，随后在过渡至热解过程中减少，并且增加到达到稳定平台以进行稳定的热解。对于所有沥青质和平均DBE进展，发现该行为相似。部署较轻的链烷烃溶剂进行沥青质沉淀会导致在解吸阶段释放出的更高种类的物种。它们主要属于CHO _x丙二烯馏分中的三类化合物与沥青质发生闭塞和共沉淀。除此之外，没有观察到沉淀溶剂对热解相中沥青质核心结构和分子图案的显着影响。DBE分布表明存在群岛沥青质分子结构。