The compression of a sample for X-ray fluorescence analysis (XRF) leads to a defined density in the pressed pellet. This guarantees reproducible sample preparation .
The following methods are used for pressing a sample:
· Direct pressing
· Pressing in aluminum cups
· Pressing into rings
· Pressing with binder
· Pressing onto a backing material
It is important for XRF that the pressed pellet is mechanically stable. When it is introduced into the analyzer, the sample is evacuated and released again after the measurement. A high degree of stability is required so that the pressed pellet does not break during these processes. Only a few materials show this stability, which can be increased somewhat by pressing in aluminum cups. For most materials, however, mixing with a binder is mandatory .