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OMI® Tube Holder

for use with OMI-2 purifier tubes

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for use with OMI-2 purifier tubes

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OMI® Tube Holder for use with OMI-2 purifier tubes



OMI® Tube Holder

OMI® Tube Holder for use with OMI-4 purifier tubes



OMI® Tube Holder

General description

OMI® Tube Holder holds the OMI® purifier tube which simultaneously removes oxygen, water vapor, CO, CO2, most sulfur compounds, most halogen compounds, alcohols, phenols to less than 10ppb. It also purifies helium, hydrogen, nitrogen, argon and methane. Color change indicates purifier exhaustion. Glass body does not diffuse air or off-gas. Furthermore, it is ideal for Hall, ECD and GC/MS detection systems. OMI®-4 purifier protects multiple instruments (three times the capacity of OMI®-2 tubes).
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 purifier tube (purchased separately).

Other Notes

  • The OMI-2 tube holder is 10 in. (25.4 cm) long with a diameter of 1.5 in. (3.8 cm) and 1/8 in. fittings.
  • The OMI-4 tube holder is 16 in. (40.6 cm) long with a diameter of 1.5 in. (3.8 cm) and 1/8 in. fittings.

Legal Information

OMI is a registered trademark of Merck KGaA, Darmstadt, Germany

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Nitrosamines have been discovered as a serious contaminant group in active pharmaceutical ingredients (API) belonging to the sartan family. This article describes a GC-MS method for the determination of nitrosamines in Valsartan tablets according to US FDA guide lines that can be used for pharma QC.

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