Fuel Filters

Filter Sample

•  Receive, Identify, & Photograph

•  Cut Various Filter Layers

•  Extract Organic Residue (Lubrication Oil, Turbine Oil)

•  Cover Hydrocarbon range of C₁₂ to C₄₄ + with a peak grouping at about C₂₅ .

•  C₁₂ to C₁₆ iso-paraffin components that are not normally found in a typical lubricating oil. These are subjected to come from the breakdown of other chemicals or are possible contaminants

Examination of Filter

•  Cut filter open for examination

•  Solvent rinses in ultra-clean solvent

•  Filtered through 1µm filter

•  Collect Particles

•  Scanning Electron Microscope (SEM)

•  Iron – rust

•  Silicon – possibly dirt

•  Zn, S, Ba, Ca – possible lube additives

•. Filtrate

• Analyze for organic composition

Microscopic Examination of Filter

•  Remove oil from filter

•  Rinse with hexane, then toluene, and finally acetone to expose filter fibers and particles on the fiber

•  Dark areas indicate color changes due to burnt oil particles trapped within the fibers

•  Digest Particles (10 to 40 µm)

•  Elemental Analysis via ICP

Library search is conducted using the Wiley 138 and NIST 98 libraries (combined total of over 200,000 compounds)

It is always appropriate to have a sample of the unused oil available for comparison purposes. This defines the concentration of additives that were originally present so that their depletion can be quantified. It also verifies the absence of contaminants in the original lubricating oil.