A Solvent Evaporator for Column Chromatography The evaporation of various organic eluents from column chromatography prior to further processing, such as spectrophotometric determination, may prove cumbersome and time consuming if a large number of samples is involved. A rapid, efficient, and inexpensive apparatus for solvent evaporation is easily constructed from readily available materials. One milliliter Biotips (Schwarz-Mann) are inserted through the openings in a 72-bole polyethylene test tube rack (Mallinckrodt). Slight enlargement of the holes in the base may be necessary. Very flexible plastic tubing such assupplied with intravenous equipment is inserted down inside the Biotips and cemented in place as shown in Figure 1. For clarity and simplicity, only two such nozzles are pictured in the figure. A manifold is constructed by drilling holes with a cork borer in the side of a 500-ml plastic wash bottle and cementing the other end of the tubing in the holes. A length of Tygon tubing is led from the wash bottle spout to a nitrogen tank with regulator and in-line filter (Aquasorb, Mallinckradt) as shown in Firmre 2. Ta
TO
Figure 1.
u
Manifold
u
Apparatus head. Side view
N2 Tank A n d Fllter
9 To H e a d
Figure 2.
Manifold
The column eluents may he collected in 10 X 75 mm or 13 X 100 mm test tubes, these being placed in an identical rack as used for the construction af the apparatus head. The height of the Biotips is adjusted to bring it within 1cm above the initial level of the solvent in the collecting tubes. The interlocking tabs and slots in the handle and base of the racks allow the apparatus head to be fitted snurlv .. . over the rack of tubes without theuse of clamos. Nitroeen " flow is remlated to prevent iplnshing of the solvenls, and a heated water hath m a y be used to hasrrn evdporatim. Ilp to :L tubes may he handed awnulrnneourl). The ~ f f i c i r n rof y the set-up is ~ u r hlhnt ether fractioni may be svapmafed in o 15'C water bath withour bwlingor humping. and 4 ml vulumesoin-heptaneat 40°C nrrevaporated with," hallan hour. ~
School of Medioine
~
~
-~~~~~~ ~
David P.Fisk
Kniversity of Southern California 1.0s Angeles, Californm 90033
Volume 50, Number 6, June 1973 / 401
