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 […]
The capillaries should be stored at room temperature (approximately 22C) in a dry place. It does not depend on the ID of the capillary. Many customers actually tape them to the wall near their CE instrument. Capillaries for CE Ordering Information
These capillaries columns are pH independent. What that means is the flow does not change significantly with different pH levels. The optimal pH will be the pH at which your analytes separate best. Click here to view Zero and Controlled flow capillaries for CE
No, these capillaries have a special covalently bonded coating on the inside capillary wall (linear polyacrylamide) that may be damaged using a laser. The outer polyimide coating should be removed only by a specific protocol. This procedure uses fuming sulfuric acid to chemically remove the outer polyimide coating. Capillaries for CE Ordering Information
Can I use the MicroSolv Window Maker or similar units on the Zero or Controlled Flow CE Capillaries?
It is not normally recommended that one use high heat to remove the polyimide coating on the capillary. This could create a “void” in the wall coating and produce erroneous results. It is best to use chemicals to remove the polyimide in this case. Be sure to follow good laboratory practices when using hazardous chemicals. […]
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 […]
The bonded or coated capillaries are only available in 1M lengths. The reason is that it is very difficult to push the bonded reagent through a 50um or 75um tube and get proper coating. Ordering Information for Controlled Flow and Zero EOF Capillaries
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 […]
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 […]
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 […]
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 […]
Is the conditioning of the Controlled and Zero CE capillaries the same as with a bare fused silica capillary?
No. Inside the front cover of the column case is a special set of conditioning steps that must be taken. It is important that these conditions be followed. You can also see these conditions on our website by clicking on this link: Controlled Flow capillary Conditioning Steps. Click here to view Zero and Controlled flow capillaries […]
The terms High, Medium and Low are based on a relative flow when compared to Bare Fused Silica Capillaries. The Controlled Flow capillary always is slower than bare silica but the High Rate is the highest of the Controlled Flow capillaries. A set of conditions on a bare silica column that provides a migration time […]
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 […]
These capillaries are available in both 50m and 75m ID width. The length of the capillary is 1 meter. Click here to view Zero and Controlled flow capillaries for CE
Will my analyte absorb to the polymer used in the Controlled or Zero Flow coated capillaries for CE?
The Controlled and Zero EOF Capillaries usually produces a very low sample to polymer interaction (wall) and absorption. Your analytes could be different however as it will depend on the hydrophobicity of your analyte. The more hydrophobic and neutral, the more chance it will be adsorbed. If it is charged it is not likely to stick. […]