Idex PEEK Frits

PEEK™ Frits

• Inert, biocompatible and metal-free
• Uniform porosity, longer filtration life
• Sealing rings manufactured from PCTFE

Patented Upchurch Scientific® PEEK Frits offer exceptionally uniform porosity. This property ensures longer filtration life and consistent frit-to-frit swept volumes. The PEEK polymer frit discs are biocompatible and inert to most solvents, making them well-suited for bioanalytical applications. PEEK’s robust properties make these products suitable for low and high pressure applications.

Disc rings, included on most PEEK frits, are made of PCTFE and are slightly thicker than the frit disc, providing enhanced sealing and excellent chemical resistance. PCTFE surrounded PEEK frits can be used up to 80 ºC, and PEEK frits alone are a good choice for applications up to 100 ºC.

Application NOTE:

Frit Volume

The term “frit volume” refers to the volume of the various fluid pathways that comprise the matrix of a frit. A standard frit is a mass of small particles fused together through a controlled process of compression and heat. Because of their shape, there are gaps between the fused particles. Fluid makes its way through these gaps, creating a pathway from one side of the frit to the other. (See the diagram, below, where the white circles represent frit particles, and the black area represents the void between the particles.)

Generally, when the frit particles increase in size, the frit’s porosity increases as well. The larger the particles, the larger the gaps between particles. Cumulatively, these gaps comprise what is known as “frit volume”. Using gravimetric determination, it has been experimentally shown that the total volume of any given frit may range from 18%–30%, depending upon the porosity of the frit.

Frit volume is calculated by determining what the mass of the frit would be if it were a solid block of material of equal size. Then the solid mass of the frit is multiplied by the percentage assigned to the porosity to determine the theoretical frit volume.

18% for 0.2 μm frits

20% for 0.5 μm frits

24% for 2 μm frits

26% for 5 μm frits

28% for 10 μm frits

30% for 20 μm frits

From a chromatographic perspective, it’s important to know the volume of the frit used in your system. It is possible for a frit to negatively impact your chromatography if the total frit volume is too large and if it is placed in an area through which the sample will pass. To avoid frit-related problems like band broadening and loss of resolution, most inline filters placed after the sample introduction point (e.g., between the injection valve and the column) are smaller in size and porosity than inline filters that are placed in areas before the sample is introduced into the flow path (e.g., between the pump and the injection valve).