This method is for the determination of pentane-insolubles in petroleum oils and is applicable to samples that are fluid at about 37 degrees C or lower temperatures. This method covers the range of 0.01 to about 20 mass-% pentane-insolubles. Solid particulate materials interfere. The data provided by this method may be used as an index to coking tendency of petroleum oils when considering their suitability as charge stocks to cracking or other processes.

More viscous or solid materials such as asphalts may be handled by using the modification described in the Appendix.

A similar test method for heptane-insolubles, for samples that are fluid at 80 degrees C, is UOP Method 614, Heptane-Insoluble Matter in Petroleum Oils by Membrane Filtration, which also mentions toluene-insolubles in a Note. ASTM Method D 4055, Pentane Insolubles by Membrane Filtration, is also similar in technique, but is written for particulates in lubricating oils rather than asphaltenes.