How to choose an HPLC column

Updated 2026-11-11

Choosing a column is mostly a sequence of five decisions. Get the first two right and the rest is optimisation.

1. Pick the separation mode from your analyte

• Small, neutral to moderately polar molecules soluble in water/organic mixtures → reversed phase (C18, C8, phenyl, PFP). This covers most pharmaceutical, environmental and food methods.
• Very polar compounds that elute at the void on C18 (metabolites, amino acids, nucleosides) → HILIC, e.g. Waters ACQUITY UPLC BEH Amide Column, 2.1 x 100 mm, 1.7 µm (186004801) or Shodex HILICpak VG-50 4E HILIC Column, 4.6 x 250 mm, 5 µm (F7630100).
• Enantiomers → chiral columns such as Daicel CHIRALPAK AD-H Chiral HPLC Column, 4.6 x 250 mm, 5 µm (19325) or the solvent-robust immobilised Daicel CHIRALPAK IA Immobilized Chiral Column, 4.6 x 250 mm, 5 µm (80325).
• Polymers by molecular weight → SEC/GPC, e.g. Agilent PLgel MIXED-C GPC/SEC Column, 7.5 x 300 mm, 5 µm (PL1110-6500) or Shodex GPC KF-806M Mixed-Bed GPC Column, 8.0 x 300 mm, 10 µm (F6028090); proteins → aqueous SEC such as Agilent AdvanceBio SEC 300 Å Protein Column, 7.8 x 300 mm, 2.7 µm (PL1180-5301).
• Sugars and organic acids → ligand-exchange / ion-exclusion columns (see the comparison).

2. Choose the stationary phase

Start with a well-end-capped, high-purity C18 (USP L1). Move to a C8 (L7) for less retention, a phenyl or biphenyl (e.g. Restek Raptor Inert Biphenyl Column, 4.6 x 150 mm, 2.7 µm (9309A65-T)) or PFP for aromatic and positional-isomer selectivity, and a polar-embedded or aqueous-stable C18 for highly aqueous conditions. If your method must run at high pH, choose a hybrid or pH-robust particle such as Waters XBridge C18 HPLC Column, 4.6 x 150 mm, 5 µm, 130 Å (186003116) (pH 1–12 per source specification).

3. Choose dimensions

• 4.6 mm ID — standard HPLC at ~1 mL/min; most pharmacopoeial methods. 150 mm is the general default, 250 mm for difficult impurity separations.
• 3.0 mm ID — saves solvent, still works on standard systems.
• 2.1 mm ID — UHPLC and LC-MS (0.2–0.6 mL/min); requires a low-dispersion system.
• Shorter columns (50–100 mm) give faster runs; longer columns give more plates.

4. Choose particle size (and particle type)

• 5 µm — robust, low back-pressure, standard HPLC (≤400 bar).
• 3–3.5 µm — more efficiency at moderate pressure.
• Sub-2 µm fully porous (e.g. Waters ACQUITY UPLC BEH C18 Column, 2.1 x 100 mm, 1.7 µm (186002352)) — highest efficiency; needs UHPLC pressure capability.
• 2.6–2.7 µm core-shell (Phenomenex Kinetex C18 Core-Shell Column, 2.1 x 100 mm, 2.6 µm, 100 Å (00D-4462-AN), Agilent InfinityLab Poroshell 120 EC-C18 Column, 2.1 x 100 mm, 2.7 µm (695775-902)) — near-sub-2 µm efficiency at lower pressure; a popular way to speed up methods on 600 bar systems.

5. Check pore size, pH and temperature limits

Use 80–130 Å pores for small molecules and ≥300 Å for proteins. Stay inside the column's pH range — silica dissolves at high pH and bonded phases hydrolyse at very low pH — and observe the maximum temperature and pressure on the product page.

Protect the investment

A guard cartridge (guard columns; see how to choose a guard column), an inline filter (fittings & inline filters) and filtered samples (syringe filter selection) are the cheapest way to extend column life.

Matching an existing method

If a method names a specific column, order the same manufacturer part number — search it in the catalog. USP codes help find alternatives, but columns with the same L-code are not automatically interchangeable; see the C18 comparison table and the column cross-reference.