Semi-automatic Transfer of Volatile Liquids to Paper Chromatograms

THE recent publication of a device for applying liquids to paper chromatograms 1 prompts this report of a simple arrangement for the reproducible transfer of small volumes which is in routine use in this laboratory for the application of steroid standards to paper chromatograms. It consists of a lambda pipette clamped in the vertical position with the pipette tip firmly against the surface of the chromatography paper which is supported on a perforated metal disk. A stream of compressed air for drying passes through holes in the metal disk against the lower surface of the paper (Fig. 1). In practice the pipette is filled with solvent and positioned while keeping a finger over the upper orifice to prevent leakage. Gradual transfer of solvent to paper begins when the finger is released. A Medtec Spotting Device was employed, but a simpler device for support of the paper and delivery of a gas stream would serve the purpose.