A brief introduction to DiatoSorb-W



DiatoSorb-W is a diatomaceous earth material that Restek will sell in packed columns and as a coated packing material (% loading with a liquid phase of your choice), which will replace Chromosorb-W products/packings. For those of you who may not know, the “W” stands for “white”, and is simply the color of the untreated, uncoated material.

If your method references USP S1A, or Chromosorb-W/AW (acid-washed), you will request/receive DiatoSorb-W/AW unless the material is designated as DMDCS (or DMCS) treated/deactivated, in which case you will receive DiatoSorb-W/HP.

If your method references USP S1NS, or Chromosorb-W/NAW (non-acid washed), you will receive/request DiatoSorb-W/NAW.


In summary:



In need of Chromosorb-W/AW, request DiatoSorb-W/AW

In need of Chromosorb-W/AW-DMDCS, request DiatoSorb-W/HP



In need of Chromosorb-W/NAW, request DiatoSorb-W/NAW



W = white

AW = acid washed

NAW = non-acid washed

HP = high performance

DMDCS = dimethyldichlorosilane (this is a deactivation treatment reagent). It may also be referred to as DMCS (dimethylchlorosilane).


For packed columns containing Silcoport-W, the name will remain the same but the starting material will now be DiatoSorb-W instead of Chromosorb-W.  The proprietary deactivation used for past and present Silcoport-W packings will remain the same.  Silcoport-W carries the USP designation of S1A.

For packed columns containing Chromosorb-W/HP, you will request/receive DiatoSorb-W/HP.  Note, Chromosorb-W/HP is known as both USP S1A and USP S1AB.


To receive a quote for a packed column or packing, please complete this form and a customer service representative will respond within one business day (Monday-Friday).

If you have any technical questions, email technical service .


Please note: DiatoSorb-W diatomaceous earth materials are not to be confused with other packings, such as Chromosorb P* (Pink crushed firebrick) or Chromosorb porous polymers**.

*Chromosorb P, P/AW, P/NAW, P/AW-DMDCS

**Chromosorb 101, 102, 103, 105, 106, 107, 108


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