Fractionating Column, Vigreux

Quick Answer: A Vigreux fractionating column is a glass column whose wall is pressed inward at regular intervals to form rows of downward-pointing indentations. Placed between the boiling flask and the still head, it gives rising vapour and returning liquid many contact points without any packing.

Indentations Instead of Packing

The indentations, made by heating the tube and pushing the softened glass inward, project into the vapour path from all sides. Condensed liquid runs down from one indentation to the next and drips back, while vapour rising through the column passes over it and becomes richer in the lower-boiling component as it climbs. With no packing, little liquid is held up in the column, so less of a small sample is lost and the column rinses clean easily.

The trade-off is efficiency. A Vigreux column gives fewer theoretical plates than a well-packed column of the same length, so it suits mixtures whose boiling points are well apart, and small-scale work where hold-up matters more than the last degree of separation. In college organic chemistry it is the usual column in a laboratory distillation apparatus set up for fractional work.

The design is named after Henri Vigreux, the French scientific glassblower who introduced it in the early 1900s. The title does not give the length or the joint sizes.

Applications

• Fractional distillation of liquid mixtures with well-separated boiling points
• Small-scale distillations where column hold-up would waste product
• Student practicals comparing simple and fractional distillation
• Vacuum fractional distillation of small quantities

Care & Handling

• Clamp the column upright; a tilted Vigreux column lets liquid run down one side and bypass the vapour.
• Wrap the column in glass wool or foil when a draught or a cold room makes the vapour condense too early.
• Inspect the indentations for star cracks, which form where the glass was worked and can spread on heating.

Specifications

Why Choose LabEquip

Colleges running organic practicals and research labs purifying small quantities of solvent keep Vigreux columns as standard stock. LabEquip lists this column among its chemistry lab equipments, together with the rod and disk column as another packing-free design; request the length and joint size via the contact page.

Frequently Asked Questions

What is a Vigreux column used for?

For fractional distillation of liquid mixtures, especially at small scale or where the boiling points are well apart. It needs no packing and holds up little liquid.

How does a Vigreux column compare with a packed column?

It is easier to use and clean and wastes less sample, but a packed column of the same length separates close-boiling liquids more efficiently.

Who invented the Vigreux column?

It is named after Henri Vigreux, a French scientific glassblower who introduced the design in the early 1900s.

Can a Vigreux column be used under vacuum?

Yes, with round-bottomed flasks, greased and clipped joints and a vacuum receiver adapter. Its low hold-up makes it a common choice for vacuum fractional distillation of small amounts.

How fast should I distil through it?

Slowly enough that a ring of condensate climbs gradually up the column and the distillate arrives at a steady drip rate. A fast rate reduces the separation.

Why is my Vigreux column not separating the mixture?

Common causes are heating too fast, heat loss from an uninsulated column, or components whose boiling points are too close for this design. Slow the rate and insulate the column first.

Last Updated: September 2026