Abstract: A custom built dynamic oxygen uptake tester was used to study the influence of nitrogen
compounds on the oxidation characteristics of the saturate fractions from mineral base
oils. Experimental results indicate that nitrogen compounds, especially quinoline and
indole, take part in the oxidation of saturates. It is also found that indole is more
active than quinoline. The latter can be oxidized partly into ketoimine, and the former is
more rapidly oxidized into acylamide. The oxidation products, ketoimine or acylamide, could
inhibit the oxidation of the complex. For lower nitrogen content, the oxidation processes
were accelerated. However, at higher nitrogen content,the oxidation induction periods were
increased. The oxidation characteristics of saturates were also dependent on the type of
catalysts presented.

Key words: nitrogen compound, oxygen consumption, oxidation, saturates

摘要： A custom built dynamic oxygen uptake tester was used to study the influence of nitrogen
compounds on the oxidation characteristics of the saturate fractions from mineral base
oils. Experimental results indicate that nitrogen compounds, especially quinoline and
indole, take part in the oxidation of saturates. It is also found that indole is more
active than quinoline. The latter can be oxidized partly into ketoimine, and the former is
more rapidly oxidized into acylamide. The oxidation products, ketoimine or acylamide, could
inhibit the oxidation of the complex. For lower nitrogen content, the oxidation processes
were accelerated. However, at higher nitrogen content,the oxidation induction periods were
increased. The oxidation characteristics of saturates were also dependent on the type of
catalysts presented.

关键词: nitrogen compound;oxygen consumption;oxidation;saturates