On-line gas electron diffraction identification of gas chromatography effluents (GC-GED)

Experiments are described which document the utility of gas electron diffraction (GED) as a means of detecting analytes emerging from the column of a gas chromatograph (GC). In these experiments electron diffraction patterns from GC effluents are made visible on a phosphor screen, and the intensities of each GC peak are recorded on line by a 1024-channel linear photodiode array detector. The technique not only indicates the presence of elutants but also provides auxiliary information on their molecular structures under favorable conditions. Minimum sample sizes of about 1 μl per component are currently required for GC-GED, but indications are that further detector enhancements will allow the recording of electron intensities from smaller samples.