PEEK tubing is a polymer tubing solution that has gained widespread use in demanding scientific and industrial applications, particularly in high-performance liquid chromatography (HPLC). PEEK, short for polyether ether ketone, is known for its outstanding chemical resistance, mechanical strength, and ability to withstand high temperatures without losing its structural integrity. These properties make it an ideal choice for HPLC systems, where precision, durability, and chemical compatibility are essential to ensuring accurate and reliable results.
In HPLC applications, tubing plays a critical role in carrying solvents, samples, and mobile phases through the chromatography system under high pressure. One of the key reasons PEEK tubing is favoured for this application is its remarkable resistance to a wide range of chemicals, including acids, bases, and organic solvents. Unlike traditional metal tubing, which can be susceptible to corrosion when exposed to aggressive chemicals, PEEK tubing remains inert and unreactive, ensuring that there is no contamination or interaction between the tubing material and the substances flowing through it. This is particularly important in analytical chemistry, where even minor contamination can compromise the accuracy of results.
Additionally, PEEK tubing provides significant mechanical strength, allowing it to handle the high pressures typical of HPLC systems, which often exceed 5000 psi. While other plastics might deform, crack, or fail under such intense conditions, PEEK’s robustness ensures that the tubing maintains its shape and performance over time. This makes it highly reliable for long-term use in HPLC instruments, where consistent performance is critical for reproducibility. Metals such as stainless steel are also used in high-pressure applications, but PEEK has an advantage in being lighter, non-metallic, and resistant to a wider variety of chemicals, making it a more versatile choice in many HPLC systems, especially in bioanalysis and pharmaceutical testing.
One specific example of PEEK tubing’s superiority in HPLC can be seen in its use for mobile phase transfer lines in bioanalytical labs. Here, the solvents used are often aggressive mixtures that can degrade standard polymer tubing and potentially leach contaminants into the mobile phase. PEEK’s exceptional resistance to these aggressive solvents ensures that the integrity of the mobile phase is maintained, leading to more accurate and repeatable results. Furthermore, because PEEK tubing is non-metallic, it avoids potential issues with metal ion contamination, which can be especially problematic in highly sensitive analyses such as those used in drug development and environmental testing.
PEEK tubing is also easy to cut and handle, allowing technicians to make precise adjustments to fit their system's requirements. Its flexibility, combined with its strength, allows it to be routed through complex instrument configurations without kinking or cracking, which can be an issue with stiffer materials like stainless steel. This flexibility is particularly beneficial in custom or intricate HPLC setups, where space constraints and equipment design necessitate creative tubing layouts.
Beyond its mechanical properties, PEEK tubing also has excellent temperature stability, which is important in HPLC applications that involve temperature-controlled processes. PEEK maintains its strength and dimensional stability at temperatures up to 250°C, far surpassing many other plastics. This makes it an ideal choice for use in systems that involve elevated temperatures, where materials like nylon or polyethylene would likely soften, warp, or fail.
PEEK tubing’s unique combination of chemical resistance, mechanical strength, high pressure tolerance, and temperature stability makes it the material of choice for HPLC applications. Its ability to withstand harsh solvents and high pressures, along with its ease of handling and versatility, allows it to outperform many alternative materials, including metals and other polymers, in the precise and demanding world of analytical chemistry. Whether used in pharmaceutical research, environmental testing, or bioanalysis, PEEK tubing ensures accurate, reliable, and repeatable results, making it an indispensable component in modern HPLC systems.