Capital HPLC

EKT Prepared Bare Silica Capillaries

EKT Prepared Bare Silica Capillaries

Bare Silica Capillaries EKT uncoated CE capillaries are made from
high quality drawn fused silica with a high degree of UV transparency. All EKT capillaries
have an outer diameter of 375μm and are available with internal diameters of 50μm and
75μm.

For convenience of handling and easy installation, the majority of CE instruments use
a cartridge which houses the coiled capillary. In most cases there are a number of standard
lengths for each instrument type. These standard lengths are given by the way in which
the capillary is coiled, i.e., each length increment should be a multiple of the coil
circumference. Capillary lengths are typically 25-75cm. Longer length capillaries, i.e.,
100cm or more are sometimes used for special applications such as the interfacing
of commercial CE instruments with a mass spectrometer.

The injection end of the capillary should be cleanly cut to give a flat surface. Poorly cut
capillaries can lead to loose polyimide coating and a cracked or shattered fused silica edge
which will lead to tailing peaks, sample carryover and a reduction in peak area precision.
It is therefore of considerable benefit for the CE user to obtain expertly prepared
capillaries. Electrokinetic Technologies prepared capillaries are cut to a high degree
of precision with the UV detection window accurately prepared and positioned. A small
length of the polyimide coating is also removed from the injection end in order to
improve sample introduction precision.Electrokinetic Technologies can also supply
prepared capillaries in non standard lengths. For customers who wish to supply their own
capillaries, we offer a precision preparation service (please contact our sales office for details).

Prepared Bare Silica Capillaries - Open Form

Capillary Replacement

After the polyimide coating is removed to form the detection window, the exposed fused silica
becomes extremely fragile and should be subjected to minimal handling. Many users
will have experienced the frustration of breaking the capillary whilst fitting it into the
cartridge unit. In order to overcome this problem, Electrokinetic Technologies can
supply prepared capillaries already fitted in the cartridge and correctly aligned with the
detection aperture. The exact alignment of the capillary detection window with the cartridge
detection aperture is essential in order to ensure maximum UV sensitivity.
Electro-Kinetic Technologies offer a capillary replacement service for all popular cartridge
formats such as Hewlett-Packard, Beckman, and TSP. For other instrument formats please
contact our sales office..

 Prepared Bare Silica Capillaries - Fitted to Beckman Cartridge

Cat.No.

Description

Price/item

Packof3

EKA1225

Beckman-25cmFusedSilicaCapillary(bare) 75µm

   

EKA1250

Beckman-50cmFusedSilicaCapillary(bare) 75µm

   

EKA1275

Beckman-75cmFusedSilicaCapillary(bare) 75µm

   

EKB1225

Beckman-25cmFusedSilicaCapillary(bare) 50µm

   

EKB1250


E
KB1275

Beckman-50cmFusedSilicaCapillary(bare) 50µm

Beckman-75cmFusedSilicaCapillary(bare) 50µm

   

 

PreparedBareSilicaCapillaries-FittedtoHPCartridge

Cat.No.

Description

Price/item

Packof3

EKA1325

HP-25cmFusedSilicaCapillary(bare)75µm

   

EKA1350

HP-50cmFusedSilicaCapillary(bare)75µm

   

EKA1375

HP-75cmFusedSilicaCapillary(bare)75µm

   

EKB1325

HP-25cmFusedSilicaCapillary(bare)50µm

   

EKB1350

EKB1375

HP-50cmFusedSilicaCapillary(bare)50µm

HP-75cmFusedSilicaCapillary(bare)50µm

   

Prepared Bare Silica Capillaries - Fitted to TSP Cartridge

  

Cat.No.

Description

Price/item

Packof3

EKA1425

TSP-25cmFusedSilicaCapillary(bare)75µm

   

EKA1450

TSP-50cmFusedSilicaCapillary(bare)75µm

   

EKA1475

TSP-75cmFusedSilicaCapillary(bare)75µm

   

EKB1425

TSP-25cmFusedSilicaCapillary(bare)50µm

   

EKB1450

EKB1475

TSP-50cmFusedSilicaCapillary(bare)50µm

TSP-75cmFusedSilicaCapillary(bare)50µm

   

  

 

 

IonMigration

Inavacuum,anioninanelectricfieldwillcontinuetoaccelerateuntilitleavesthefield.However,ina

fluidmediumitwillexperienceanopposingviscousresistanceincreasingwithincreasingvelocity.

       
         Symbols:

         E=Field,

            η =fluidviscosity
         a=effectiveradius
         u=velocity

         q=chargeonion


Theacceleratingforce(F) isgivenby,F = q E

          Theviscousresistance(f) isf= -6πηa u

Aconstantvelocityisobtainedwhenf=-Fwhich,combiningtheaboveexpressionleadstothefollowing,


u=(q/6
πηa ) Eoru = µepE

Theabovebrackedquantityisreferredtoastheelectrophoreticmobility(µep)oftheion.Themigration

speed(u)dependsonthecharge(q)andtheeffectiveradius(a)..


 

 

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