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OMI® Purifier Tube

OMI-2 Purifier Tube


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General description

OMI® purifier tubes simultaneously remove oxygen, water vapor, CO, CO2, most sulfur compounds, most halogen compounds, alcohols, phenols to less than 10ppb. They also purify helium, hydrogen, nitrogen, argon and methane. Color change indicates purifier exhaustion. Glass body does not diffuse air or off-gas. Furthermore, they are ideal for Hall, ECD and GC/MS detection systems.
The OMI is a polishing purifier that removes many contaminants that other upstream purifiers miss. It will simultaneously and irreversibly remove moisture, oxygen, carbon monoxide, carbon dioxide, most sulfur compounds, most halogen compounds, alcohols, and phenols to less than 10 ppb. It is recommended that an OMI be installed in carrier gas streams just upstream of every GC. It consists of two components:
  • A re-useable tube holder that is installed into the gas delivery system. The use of polycarbonate provides see-through capability along with safety.
  • A purifier tube containing an indicating resin (changes color from black to brown when exposed to as little as 1 ppm of moisture or oxygen). The use of glass provides see-through capability and prevents diffusion of room contaminants into the gas stream.

Spent purifier tubes are easily replaced. Simply unscrew the end assembly from the tube holder and replace it with a new purifier tube. The design prevents room air from entering the new tube during installation (protective foil covers on each end are only pierced as the end assembly is screwed back onto the tube holder to complete installation).

Note: This item requires a re-useable tube holder (purchased separately).


First time users must order both a purifier tube and a reuseable holder (P/N 23921).

Legal Information

OMI is a registered trademark of Sigma-Aldrich Co. LLC



Signal Word


Hazard Statements

Hazard Classifications

Eye Dam. 1 - Skin Corr. 1B - Water-react 1

Supplementary Hazards

Storage Class Code

4.3 - Hazardous materials, which set free flammable gases upon contact with water



Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Certificate of Analysis

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Certificate of Origin

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