IP 156: Determination of hydrocarbon types in petroleum products - Fluorescent indicator adsorption method

Overview:

This document specifies a fluorescent indicator adsorption method for the determination of hydrocarbon types over the concentration ranges from 5 % (V/V) to 99 % (V/V) aromatic hydrocarbons, 0,3 % (V/V) to 55 % (V/V) olefins, and 1 % (V/V) to 95 % (V/V) saturated hydrocarbons in petroleum fractions that distil below 315 °C. This method can apply to concentrations outside these ranges, but the precision has not been determined.

When samples containing oxygenated blending components are analysed, the hydrocarbon type results can be reported on an oxygenate-free basis
or, when the oxygenate content is known, the results can be corrected to a total-sample basis. This test method is applicable to full boiling range
products. Cooperative data have established that the precision statement does not apply to petroleum fractions with narrow boiling ranges near the 315 °C limit. Such samples are not eluted properly, and results are erratic. It does not apply to samples containing dark coloured components that interfere with reading the chromatographic bands that cannot be analysed.