Determining the Engine Oil’s TBN by Semi-Derivative Voltammetry

A new method was proposed for determining total base numbers (TBN) of engine oils with semi-derivative Voltammetry. This method uses acetone containing hydrochloric acid as neutralization agent for titrating TBN, the remained hydrochloric acid reacts with insoluble substances, the insoluble substances are transformed into soluble and electro-active ones in acetone. Through determining the concentration of electro-active substances in the solution, oil’s TBN could be evaluated accurately. The experimental results had shown the method is simple, rapid environmentally-friendly, and could be used at-site.