Adaptation of a Photometer for the Direct Recording of Column Chromatograms

Abstract

THE direct recording of chromatograms presents several advantages: it saves time and labour and eliminates all errors inherent in a fraction collector. To actuate the recorder, a suitable method of detecting the eluting bands must be used. Out of several possibilities, absorption of light, especially ultraviolet light, seems the most generally useful, since many laboratories are equipped with a photometer. Although such devices are already mentioned in the literature^1,2, a detailed description seems to be lacking. The only drawback of such a method lies in the rather short expectancy of life of the hydrogen lamp used as source of ultra-violet light. This limits the application of the direct photometric recording method to chromatography of short duration (a few hours). Only the most difficult separations need, however, days or weeks, and most column elution methods can be speeded up by adequate pressure without excessive diminution in efficiency. Such a photometric direct recording device for column chromatograms was set up in our laboratory and Fig. 1 shows a typical result of a chromatography terminated in less than 2 hr., which would have taken much longer using the earlier methods (fraction collector—measuring each fraction—plotting the result and calculating).