A Dealership Gets Pancaked: (Particulate Examination, PMA Level 2)
Samples were submitted for analysis from an automotive dealership in the Midwest. The client was noticing debris building up on their cars that wasn’t washing away like normal road dust. It tended to stick to the vehicles and when they scrubbed it off, sometimes it was damaging the finish leaving a nasty road rash.
Samples were submitted for the test Particulate MicroAnalysis Level 2. Advanced MicroAnalytical Particulate Micro-Analysis or (PMA) service provides a comprehensive means for our clients to gain insight about materials present at their locations. With a clear, concise, and informative report, detailed particle analysis data, and a helpful summary documenting findings, a PMA report has been a useful tool for a wide range of clients for years. Using a range of microscopy methods, ranging from optical to spectral imaging, fluorescence, and electron microscopy, our team of analysts can examine all of the varying components of any dust or residue samples.
Our Findings:
A significant amount of the particles observed in this bulk sample appeared to represent large organic flakes of partially clear or browned flat tissue material. These flat fragments of tissue appeared to have plant or leaf like structure when examined in the SEM. This often included some small structures that could be associated with leaf guard cells or surface contact from woody tissue. Almost all of these flakes also showed signs of association with spherical grains of what appeared to be fairly homogenously processed starch material. These starch grains were visible with optical microscopy to be stuck to the surface of these flakes, and showed little size variation – further confirming that they appeared to come from a single common source and were likely at least partially processed.
FTIR examination of the individual flakes showed a complex cellulose spectrum, with broadened sugar or starch structure. A comparison of the FTIR spectrum isolated from individual flakes showed a very strong match to a processed commercial bleached flour material – which would be consistent with the structure of the flakes – identified as vegetative tissue flakes.
There was also a significant amount of extremely fine mineral debris observed in this sample. These mineral and salt particles were typically under 2 microns in size. These particles ranged across a number of different compositions, with quartz, mica, feldspar, clay, and calcite type particles being observed commonly on the sample. Other particles observed were salts of various types, including carbonates, sulfates, and chlorides. These salts were commonly found either in larger flakes or semi-crystalline nodules, or enmeshed into the softer tissue particles.
With examination of the surface and sub-structure of the tissue flakes, many of these flakes showed signs of the fine particles being embedded or enmeshed into the structure of the flakes.
Since the mineral debris was integrated into the starch and vegetative matter. It was most likely that the persistent damage to the surface of the vehicles was due to abrasive interaction between the mineral particles and the surface of the paint and clear coat. The vegetative flakes may be increasing the surface contact of the mineral particles – embedded in the vegetative tissues – with the coating on the vehicles.
Subsequent analysis of samples taken by the State from the roof and ventilation system of a bakery adjoining the dealership showed a match to the material found on the cars revealing the source of their sugary starchy sticky wicket. The confirmatory analysis from the State was enough for them to step in and the partially burnt flour from the bakery ceased to rise.
MATERIALS SCIENCE AND FORENSIC SCIENCES LABORATORY
