CE vs LC vs GC — SCI.MICROSEP

Short view

CE is compelling when electrophoretic mobility, low sample consumption, electrical control, or charged-species selectivity is central. LC offers a broad range of stationary-phase/mobile-phase retention mechanisms for liquid-compatible samples. GC is exceptionally mature for compounds that can enter the gas phase and tolerate the inlet and column temperatures.

These are platform-level distinctions, not a method-selection algorithm. Detector choice, sample preparation, matrix, and the required evidence can overturn an apparently obvious choice.

Comparison

First-orientation comparison; application-specific method selection still requires experimental and validation evidence.
Dimension	CE	LC / HPLC	GC
Dominant basis	Differences in electrophoretic mobility; observed motion may also include electroosmotic flow	Differential retention between a liquid mobile phase and a stationary phase	Volatility and differential stationary-phase interaction under controlled temperature
Typical sample state	Small liquid sample in compatible electrolyte conditions	Liquid or soluble sample compatible with mobile phase	Volatile sample or analyte made GC-compatible
Common strength	Low consumption and high efficiency for suitable charged species	Broad chemistry and mature column, mode, and detector ecosystem	High-efficiency analysis and strong GC–MS evidence for suitable volatile compounds
Frequent constraint	Optical path, adsorption, conductivity, migration reproducibility	Solvent, pressure, matrix effects, equilibration	Volatility, thermal stability, inlet discrimination
Consumption versus detectability	Very little sample may be injected, but short optical paths can limit concentration sensitivity	Injection and flow scale vary widely; matrix and detector response may set the practical limit	Preconcentration can improve detectability, while inlet transfer and discrimination can lose analyte
Miniaturization	Electrical control scales well; high voltage, injection, surfaces, and detection remain	Pressure, pumps, columns, solvents, extra-column volume, and interfaces remain	Temperature, carrier gas, introduction, and calibration remain

Terminology note: MEKC and CEC are frequently grouped with CE in laboratory conversation because they use related capillary instruments. Strictly, their chromatographic retention mechanisms place them among neighboring capillary electromigration techniques rather than CE itself. HPLC and UHPLC describe LC implementations; they are not additional retention mechanisms.

Choose CE when…

differences in electrophoretic mobility answer the selectivity problem;
the available sample amount is severely limited;
electrical control and chip integration are valuable;
the detector and background electrolyte meet the evidence requirement.

Choose LC when…

a stationary-phase/mobile-phase system offers the needed selectivity;
the analytes are nonvolatile or thermally unsuitable for GC;
the workflow benefits from mature LC–MS or optical detection;
column chemistry, pressure, solvent, and matrix constraints are manageable.

Choose GC when…

the compounds are volatile or can be made GC-compatible;
headspace, thermal desorption, or another gas-phase introduction is informative;
temperature programming and an open-tubular or packed column fit the mixture;
GC–MS or a selective GC detector provides the required evidence.

Common misunderstandings

A faster method is not automatically more informative.
Low sample consumption is not the same as a low concentration detection limit.
A lower instrumental detection limit may not overcome sampling or matrix uncertainty.
Retention or migration time alone is rarely conclusive identity.
“Portable” describes a system claim, not a single miniaturized component.
Solvent use, waste, power, and consumables require a complete workflow comparison.

Authoritative terminology

AI-assisted technical revision; human scientific review is required before production publication.