USP L33 column: SEC silica for dextrans (4-500 kDa)
Size-exclusion packing on spherical, pH-stabilized silica able to separate dextrans of about 4,000-500,000 Da.
Mode: size-exclusion Typical pH range: about 2.5-7.5 (silica-based SEC)
Typical uses
- Molecular weight distribution of dextrans and iron-dextran type products
- Polysaccharide and some protein size separations
Common sizes (length x internal diameter, particle size)
- 300 x 7.8 mm, 5-8 um
- 300 x 7.5 mm, 10-13 um
Example columns sold as USP L33
From the makers' own USP code lists and product pages, checked October 2026. Examples only, not an endorsement. Columns with the same code can still differ in selectivity; if the monograph names a column in its notes, start with that one.
| Maker | Product family | Particle | pH range |
|---|---|---|---|
| Waters | ACQUITY UPLC Protein BEH SEC 125A | BEH hybrid 1.7 um (SEC) | not stated in source |
| Resonac (Shodex) | PROTEIN KW-800 series | silica-based SEC packing | not stated in source |
| Shimadzu | Shim-pack Bio Diol series | diol-bonded silica (SEC) | not stated in source |
| Welch Materials | Xtimate SEC-300 (also SEC-120/500/700/1000) | silica-based SEC packing | not stated in source |
4 makers listed, so a tender written by USP code stays open to competition.
Tender wording (brand-neutral)
HPLC column with USP L33 packing (SEC silica for dextrans (4-500 kDa)), 300 x 7.8 mm, 5-8 um (length x internal diameter, particle size); stainless-steel or equivalent hardware with standard fittings; recommended pH and temperature range to be stated by the bidder; each column supplied with its certificate of analysis and test chromatogram, batch/lot number and serial number; shelf life not less than 2 years from delivery; any make meeting the USP L33 designation and the stated dimensions is acceptable.
Size:
Changing length or particle size
You can keep the USP L33 packing and use a different length, particle size or diameter within the harmonized USP 621 limits. Check your columns with the calculator.
Related column types
L25 Polymethacrylate SEC, water-soluble polymers (MW ~100-5000) | L39 Hydrophilic polyhydroxymethacrylate gel (SEC) | L59 Protein SEC on coated silica/hybrid (5-7000 kDa)
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