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Why must samples be vaporized for gas chromatography?

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What is chromatography? — chromatography Overview of the chemical technique of chromatography.

In gas chromatography, samples must be vaporized because the technique relies on a moving gas stream—typically an inert gas like helium or argon—to act as the mobile phase that carries the sample through the column.12

Because the separation process requires the sample to be transported through the system by this gaseous mobile phase, liquid samples must be converted into a vapor state before injection. This method is specifically designed for substances that can be vaporized without undergoing decomposition. For substances that do not easily vaporize, chemists may use chemical derivatization to enable successful volatilization and separation.134

This requirement distinguishes gas chromatography from liquid chromatography, where the use of a liquid mobile phase eliminates the need for vaporization, allowing for the analysis of a broader range of substances.4