Laboratory Tubing

In addition to it's use as a part of a peristaltic pump flexible tubing is often used for a variety of purposes in a laboratory. In chromatography, it used to get the eluent from the pump to the column, from the column to the detector, and finally from the detector to the fraction collector.

A variety of different inexpensive plastic tubing materials are available for laboratory use. The different materials have different physical properties and different chemical compatibilities.

Vinyl tubing is the least expensive and most commonly used tubing. It is soft, flexible and transparent. It is fine for use with most aqueous solutions, including dilute acids and bases. Vinyl tubing should not be used with organic solvents; the plasticizers dissolved in the vinyl will tend to migrate into the solvent and the tubing will become brittle with time.

Silicone tubing is the softest and most flexible tubing. It is translucent white; you can see light through the tubing and easily locate a meniscus, but not see shapes through the tubing. Unlike vinyl tubing, there is no plasticizer dissolved in the tubing material; the tubing is pure polymerized silicones with nothing to leach out. This makes silicone tubing suitable for use with most solvents, especially when used at room temperature and with short (< 24 hr) contact periods.

Polyethylene tubing is a "semi-rigid" tubing material. It can handle significantly high pressures than either the vinyl or silicone tubing. While it is still a translucent material, it is significantly more opaque than silicone and it can be difficult to determine the position of either a meniscus or an air bubble. Polyethylene tubing is ideal for plumbing a low-pressure chromatography system. The increased rigidity of the polyethylene tubing when compared to vinyl tubing can make the layout appear neater and more organized.

FEP (Fluorinated Ethylene-Propylene) tubing is also "semi-rigid". It can handle pressure similar to those that polyethylene tubing can handle. It is resistant to any chromatographic solvent and is especially useful when using organic solvents.