Preservation techniques are usually implemented to ensure that no PM is lost from the filter during storage and transportation. One effective method compatible with various XRF analysis methods involves the encapsulation of the PM filter between two laminated polymeric sheets using an automatic device called SMART STORE®. This approach offers several advantages, including the preservation of the PM filter's structural integrity, and protection against external contaminations. Furthermore, by removing the stretching ring of PTFE filters, this method enables the direct illumination of the filter surface by the X-ray beam in TXRF analysis .