High-Performance Liquid Chromatography (HPLC) and Gas Chromatography (GC) are both separation techniques, but they differ in many ways. Here’s a comparison:
1. Mobile Phase
- HPLC: liquid solvent
- GC: inert gas (helium, nitrogen, hydrogen)
2. Sample Type
- HPLC: works with non-volatile, polar, or thermally unstable compounds
- GC: works with volatile, thermally stable compounds
3. Column
- HPLC: packed or capillary column with liquid stationary phase
- GC: capillary or packed column with gas-solid or gas-liquid stationary phase
4. Detection
- HPLC: UV, PDA, fluorescence, MS, refractive index
- GC: FID, TCD, ECD, MS
5. Temperature
- HPLC: room temperature or slightly heated
- GC: column must be heated to vaporize samples
6. Speed and Efficiency
- HPLC: high resolution, good for large molecules, slightly slower for small volatile compounds
- GC: very fast and efficient for small volatile molecules
7. Applications
- HPLC: pharmaceuticals, proteins, polymers, food, environmental analysis
- GC: organic solvents, hydrocarbons, gases, flavors, forensic analysis
In short:
- HPLC → liquid-based, works for non-volatile and polar compounds.
- GC → gas-based, works for volatile and thermally stable compounds.
- Choice depends on sample properties and analysis needs.