A Simple Chromatography Column We have developed a cheap and efficient system which replaces completely the traditional stopcock column in our laboratory. The column (see figure) ends in a cone a t an angle of about 30'; to this a 2-cm capillary tuhe is fused (diam. 8 mm ext. 2 mm int.). We enlarge a piece of 5-cm Teflon tubing (diam. 1.8 mm ext. 1-1.2 mm)' at one end with a hot conical pinzin order to form a small ridge, drop it into the column, so that its untreated end passes through the capillary tube and draw it down a hit until the ridged end sits tight in the glass tuhe. The effluent is regulated by means of a hose clip. This simple device has many advantages. Precision: The dead volume at the orifice is minimum as in expensive precision bore columns. Tightness: No loss of liquid is observed (in contrast to frequent misadventures with stopcocks) provided that the ridge on the Teflon tuhing is undamaged. Effluent control: The flow is easv to adiust down to even verv slow rates, which are never reproducible wit
