From the analysis of many different oils, we have learnt that intensive homogenisation of samples using a homogenizer or by ultrasound is a fundamental prerequisite for reproducible results.
According to ASTM D 4377-00, in analysis using a pyridine-free reagent, a mixture of a KF solvent (for example Hydranal-Solvent) and xylene must be added to the titration vessel. Hydranal-Solver (Crude) Oil fulfils all these requirements. Besides volumetric method we tested also coulometric titration where Hydranal-Coulomat Oil successfully worked in cell with diaphragm.
Download the full Laboratory Report for Crude Oil (L 108) here