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Which kinds of substances can liquid chromatography separate that gas chromatography cannot?

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

The primary limitation of gas chromatography (GC) is its reliance on the vaporization of samples, which means it is best suited for compounds that can be vaporized without decomposing. While many substances can be chemically derivatized to facilitate volatilization, this process is not always feasible for all compounds.1

In contrast, liquid chromatography (LC) eliminates the requirement for vaporization because it utilizes a liquid mobile phase. Consequently, LC can separate a much broader range of substances that are not amenable to GC, including:1

Inorganic ions1
Amino acids1
Drugs1
Sugars1
Oligonucleotides1
Proteins1

Because LC does not require the sample to be in the gas phase, it is the premier method for separating complex organic and biological substances. It is particularly vital in biotechnology for the purification of proteins and peptide hormones. While GC is highly effective for volatile compounds, LC provides the versatility necessary to analyze thermally unstable or non-volatile species that would otherwise decompose under the high temperatures required for gas-phase analysis.12