What Chromatograms Can Teach Us About Our Analytes

Gas chromatography (GC) is among the richest data-producing techniques in analytical chemistry. A chromatogram can provide a wealth of information about an individual analyte in a sample, about the sample itself, and about how well the instrument is performing. Traditional isothermal chromatograms provide useful information about the thermodynamics and kinetics of the analyte-stationary phase interactions and whether these are changing over time. They also provide measures of instrument performance through theoretical plate and tailing factor calculations. Many of these determinations are automatically performed by today's data systems, but they trace their origins to calculations and simplifications that were done in days when chromatograms were printed on rolls of paper and calculations were done with slide rules. We will see how our data systems both assist and hinder in obtaining maximum information from chromatograms.