What does a peak on a gas chromatogram represent?

In gas chromatography, a peak on a chromatogram represents a separated component of the analyte.1

Each peak provides both qualitative and quantitative information:

• Qualitative Analysis: The position of the peak, measured by its retention time—the interval between the injection of the sample and the detection of the component—is used to identify the substance by comparing it with known standards.1
• Quantitative Analysis: The size of the peak, typically measured by its area or height, is proportional to the amount or concentration of that specific component in the sample.21

While peak area is generally used for quantitative measurements, peak height is often utilized for narrow peaks where determining the area accurately is difficult. The overall chromatogram serves as a visual record of these separated components as they exit the column and are registered by the detector over time.21