Are the Zero and Controlled Flow Capillaries compatible with organic solvents?

The sulfonic acid polymer and/or linear polyacrylamide polymer is covalently bonded to the capillary wall and therefore is fully compatible with organic solvents such as acetonitrile and DMF. Essentially, the product has the same compatibility conditions as type A and B silica-based HPLC bonded phases. For example, it is known that strongly acidic conditions may […]

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Do you sell CE capillaries with pre-made windows?

We do not sell CE capillaries with a pre-made window for a few reasons; most importantly, the window is fragile often causing damage during shipping. In order to ensure quality capillaries are delivered to our customers, it is best that the end-user makes the window themselves. Another reason we do not offer these capillaries with pre-made windows is […]

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How can I remove polyimide from your capillaries without using heat?

To remove polyimide coating from our Simplus™ brand or Zero™ or Controlled Flow™ capillaries for CE without using heat, it is best to use fuming sulfuric acid at 100°C. You may want to heat the acid on a hot plate in a small shallow plate, using a fume hood and all the safety equipment needed. Then dip the capillary into […]

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How do I remove a blockage in my CE capillary?

If you observe a sudden drop in current, the problem could be due to a particle causing a blockage in the capillary. If this occurs, try flushing the capillary with filtered, CE-grade DI water. To do this, simply inject the water into the capillary with a proper syringe. Inject in the reverse flow direction because particulates […]

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How do the CE capillaries provide different amounts of flow?

We coat the bare fused silica with a proprietary polymer that has a large amount of Sulfonic acid groups exposed to the lumen of the capillary. The different flow rates of the columns are due to differing amounts of polymer. The more the polymer the less of a flow. Click here to view Zero and […]

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How does the Controlled Flow CE Capillary work?

The Controlled Flow™ CE capillary is made from a standard bare fused silica CE capillary but has an inner coating which is covalently bonded with a neutral polymer that has a controlled amount of sulfonic acid groups bonded to it. These sulfonic acid groups are always 100% ionized regardless of the pH of the buffer so the flow is independent of the buffer. The EOF is […]

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What is a Zero EOF CE capillary mostly used for?

There are many uses for Zero EOF in HPCE. One use is to allow analytes to separate based on electrophoretic mobility only. The Zero EOF capillary is an excellent choice for this technique because, regardless of the pH you use to ionize your analytes, the flow will still be zero. Another use is cIEF. Click […]

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