Nature of a residue

A white residue in the form of powder was deposited in a factory, causing fear that it could pollute the products manufactured and induce non-compliance. The plant manager is worried: where does this residue come from? What is its nature and origin? Is it limescale or another matrix that could be causing a malfunction?

Polymex was able to answer the client's questions to provide him with the information necessary to resolve his problem.

The team's mission was therefore to analyze this deposit in order to understand its nature. Given our client's suspicion, we opted for an elemental analysis by SEM/EDX.

The latter allows us to establish an atomic inventory of the sample, focusing on the presence of CaCO3.

The analysis of the deposit found in the factory led to unexpected results: Indeed its residue was not made up of Limestone but of Sodium and Chlorine, respectively 29% and 33%. The presence of these elements probably comes from an NaCl matrix.

As you can see in the figure opposite, the SEM/EDX analysis also revealed the presence of Sulphur, Carbon and Oxygen, which could come from an organic matrix.

A complementary analysis by Py/GCMS would allow us to determine the exact nature of this organic matrix.

Thanks to this expertise by SEM/EDX and proposal to continue the study with the help of an analysis by Py/GCMS, our client can now reflect on the reason for the occurrence of this residue composed mainly of NaCl.