When the biodiesel enters the crankcase, its degradation can lead to the formation of organic acids and polymerisation, to the point of clogging the system and the internal combustion engines. Therefore, this article proposed the study of lubricant oils in order to trace its biodiesel contamination. The results showed that in relation to the viscosity at 40°C there was reduction above the limit allowed for some samples. The viscosity index results showed considerable changes. Using infrared spectroscopy was noted that the contamination by fatty acid esters does not follow a pattern related to time of use in the motor. However, as the lubricant oil samples were used, they probably contain degradation products that altered the levels of oxygenated compounds. For this reason, the mass spectrometry coupled to gas chromatography quantified the predominant oil and fat steroids contents and confirmed the contamination by biodiesel.

中文翻译：

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通过燃料稀释产生的生物柴油污染监测柴油发动机中使用的润滑油

当生物柴油进入曲轴箱时，其降解会导致有机酸的形成和聚合，从而导致系统和内燃机堵塞。因此，本文提出对润滑油进行研究，以追溯其生物柴油污染。结果表明，相对于 40°C 时的粘度，某些样品的粘度降低到了允许的限度以上。粘度指数结果显示出相当大的变化。使用红外光谱注意到脂肪酸酯的污染不遵循与电机使用时间相关的模式。然而，当使用润滑油样品时，它们可能包含改变含氧化合物水平的降解产物。为此原因，