PEEK Tubing: What It Is for HPLC?
Poly Ether Ether Ketone (PEEK) tubing is common in chromatography laboratories and is a popular replacement for stainless steel tubing. PEEK tubing is biocompatible and chemically inert to most commonly used solvents. PEEK tubing is flexible and has a smooth internal surface. PEEK is a high-performance engineered polymer with mechanical- and chemical-resistance properties that absorb high temperatures, making it highly resistant to thermal degradation. PEEK tubing has one of the highest strength-to-weight ratios of any thermoplastic and the strength required to withstand continuous use at HPLC pressure.
PEEK Tubing can withstand typical HPLC pressures, up to about 10,000 PSI, and has a broad pH range of 0-14. PEEK tubing has a very smooth internal surface, which causes less turbulence than the similarly sized metal tubing. Of all our polymer tubing materials, PEEK is the least permeable to gas.
How Do You Cut PEEK Tubing?
One of the main advantages of PEEK Tubing is it can easily be cut in the laboratory. Using a PEEK tubing cutter provides the most accurate cut, which enables leak-free HPLC connections. It will provide a clean, burr-free, 90-degree cut for your 1/16” or 1/8” OD tubing. These tubing cutters have guide holes for the tubing to go through, which ensures precise cutting. When purchasing a 5’ length of PEEK tubing, it is important to know that, when they ship from the factory, they are rough cut. A trim cut should be made before use; we recommend the IDEX PEEK tubing cutter.
When Should I NOT Use PEEK Tubing?
The following solvents are usually not recommended for use with PEEK tubing: nitric acid; sulfuric acid; halogenated acids, such as hydrofluoric acid and hydrobromic acid (hydrochloric acid is approved for use in most applications); and pure halogenated gases. Additionally, due to a swelling effect, be cautious in using the following solvents with PEEK tubing: methylene chloride, THF, and DMSO in any concentration and acetonitrile in higher concentrations.