Cleaving Fused Silica Capillary Tubing

Synthetic fused silica capillary tubing continues to be a vital material in the separation sciences. In this application note, we discuss common tools and suggested methods used for routine cleaving of capillary tubing.

BY JOE MACOMBER, MOLEX Scientists around the world employ fused silica capillary tubing daily in a range of analytical applications, with the most common being GC, CE, Capillary LC, and MS.

It is common for end users to cleave the capillary to its operational length, or cleave it periodically during use. Cutting capillary tubing can be accomplished by a number of methods (1). The most common method, referred to as a standard cleave, can be accomplished with different cleaving tools, including diamond tip pencils, sapphire pens, and ceramic wafers. An elaborate device using a rotating diamond blade has limited use.

A ceramic wafer, often referred to as a “cleaving stone” is the most efficient, cost effective tool. Using a Molex - Polymicro Technologies™ cleaving stone, this simple cleaving method yields a high quality end face finish and works well for many applications.