Ionic Coated CE Capillaries
 
 
 
 NaAMPS Coated Capillaries (Negatively Charged pH Independent)
In collaboration with Chemical Solutions in the USA, Electro-Kinetic Technologies have introduced a unique anionic capillary coating based on a stable polymer incorporating sulphonic acid functional groups (abbreviated as NaAMPS) and a corresponding positive charged capillary which is particulary suited to the separation of basic proteins. The NaAMPS for is available in a range of capillaries with different, but pH independent EOF rates. Zero flow capillaries are also available.

NaAMPS capillaries are manufactured under the strictest GMP/GLP conditions in order to ensure reliability and excellent batch to batch reproducability. In contrast to most other coating materials, NaAMPS coated capillaries are extremely stable and have a considerably long lifetime.

This polymeric coating with surface sulphonic acid groups (NaAMPS coating) has, unlike bare silica, a clearly defined pKa value. The surface is therefore fully ionised over a wide pH range. The leads to a reasonably constant EOF over the same pH range.

The figure on the right shows the comparative EOF rates on bare silica and an EKT capillary with NaAMPS coating.

Effect of pH on EOF for Bare Silica Compared to NaAMPS Coated Silica

When developing methods for bare silica CE by varying the buffer pH, it can become confusing as changes in pH alter both the analtye electrophoretic mobility and the EOF.

The use of NaAMPS coated capillaries allows the user to easily assess the effect the change of pH has on the selectivity for their samples without the inconvenience of EOF changes.

NaAMPS capillaries are available from EKT with 3 different surface charge densities which enable the user to choose which degree of electro-osmotic flow is required.

NaAMPS Capillary Types

High Flow - Where a high electro-osmotic flow is required over a large pH range.
Medium Flow - Medium density surface charge, produces a moderate electro-osmotic flow
Low Flow - Generates a low EOF and is particularly useful for isoelectric focussing avoiding the need for complex and costly additives.

Advantages of NaAMPS

Decreased Sample - Wall Interactions
pH Independent Electro-Osmotic Flow
Adjustable Electro-Osmotic Flow
Reproducable Manufacturing Process
Good Stability and Lifetime

Acidic Compounds on Bare Silica

Analytes

1. Methyl Phenol (marker),
2. 2-naphthalenesulphonic Acid,
3. Benzenesulphonic Acid

At pH 8.7 the EOF carries the analytes towards the detector despite their own motion in the opposing direction. At pH 4.0 the EOF is no longer strong enough and the acidic sample now migrate in the opposite direction.

Acidic Compounds on NaAMPS Coated Silica

The use of NaAMPS coated capillaries shows that the separation is very stable to changes in pH which ensures greater method ruggedness.

The use of NaAMPS coated capillaries has the following implications for CE and MECC method development

Improves separation efficiency for biomolecules
improves use pH to adjust selectivity without affecting EOF
ideal for chiral separations
operate MECC over a wide pH range







Ordering Information
The open format capillaries are supplied precut to the required size with the UV window correctly positioned to fit the specific instrument manufacturer’s cartridge system. The capillary ends are expertly cut to ensure precise sampling.

Open Format Please specify both effective length and total length when ordering

Description

Cat. No.

Price (£)

  

0-35cm Coated Capillary (Low Flow) 75µm

EKE1125

0-35cm Coated Capillary (Low Flow) 75µm (Pack of 3)

EKE1125-3

35-65cm Coated Capillary (Low Flow) 75µm

EKE1150

35-65cm Coated Capillary (Low Flow) 7m (Pack of 3)

EKE1150-3

70-100cm Coated Capillary (Low Flow) 75µm

EKE1175

70-100cm Coated Capillary (Low Flow) 7m (Pack of 3)

EKE1175-3

0-35cm Coated Capillary (Low Flow) 50µm

EKF1125

0-35cm Coated Capillary (Low Flow) 50µm (Pack of 3)

EKF1125-3

35-65cm Coated Capillary (Low Flow) 50µm

EKF1150

35-65cm Coated Capillary (Low Flow) 5m (Pack of 3)

EKF1150-3

70-100cm Coated Capillary (Low Flow) 50µm

EKF1175

70-100cm Coated Capillary (Low Flow) 5m (Pack of 3)

EKF1175-3


Low Flow NaAMPS Coated Capillaries – Cartridge Refit Service
Beckman format Total length is nominal length plus 7cm after detection window

Description

Cat. No.

Price (£)

  

Beckman 20cm Coated Capillary (Low Flow) 75µm

EKE1225

Beckman – 20cm Coated Capillary (Low Flow) 7m (Pack of 3)

EKE1225-3

Beckman – 50cm Coated Capillary (Low Flow) 7m

EKE1250

Beckman 50cm Coated Capillary (Low Flow) 75µm (Pack of 3)

EKE1250-3

Beckman 70cm Coated Capillary (Low Flow) 75µm

EKE1275

Beckman 70cm Coated Capillary (Low Flow) 75µm (Pack of 3)

EKE1275-3

Beckman 25cm Coated Capillary (Low Flow) 50µm

EKF1225

Beckman – 25cm Coated Capillary (Low Flow) 5m (Pack of 3)

EKF1225-3

Beckman – 50cm Coated Capillary (Low Flow) 5m

EKF1250

Beckman 50cm Coated Capillary (Low Flow) 50µm (Pack of 3)

EKF1250-3

Beckman 70cm Coated Capillary (Low Flow) 50µm

EKF1275

Beckman 70cm Coated Capillary (Low Flow) 50µm (Pack of 3)

EKF1275-3


HP Format capillary fitted to Hewlett-Packard Cartridge

Description

Cat. No.

Price (£)

  

HP – 25cm Coated Capillary (Low Flow) 7m

EKE1325

HP – 25cm Coated Capillary (Low Flow) 7m (Pack of 3)

EKE1325-3

HP 50cm Coated Capillary (Low Flow) 75µm

EKE1350

HP 50cm Coated Capillary (Low Flow) 75µm (Pack of 3)

EKE1350-3

HP – 75cm Coated Capillary (Low Flow) 7m

EKE1375

HP 75cm Coated Capillary (Low Flow) 75µm (Pack of 3)

EKE1375-3

HP – 25cm Coated Capillary (Low Flow) 5m

EKF1325

HP – 25cm Coated Capillary (Low Flow) 5m (Pack of 3)

EKF1325-3

HP 50cm Coated Capillary (Low Flow) 50µm

EKF1350

HP 50cm Coated Capillary (Low Flow) 50µm (Pack of 3)

EKF1350-3

HP – 25cm Coated Capillary (Low Flow) 5m

EKF1375

HP 25cm Coated Capillary (Low Flow) 50µm (Pack of 3)

EKF1375-3


TSP Format Capillary Fitted to TSP Cartridge

Description

Cat. No.

Price (£)

  

TSP 25cm Coated Capillary (Low Flow) 75µm

EKE1425

TSP – 25cm Coated Capillary (Low Flow) 7m (Pack of 3)

EKE1425-3

TSP – 50cm Coated Capillary (Low Flow) 7m

EKE1450

TSP 50cm Coated Capillary (Low Flow) 75µm (Pack of 3)

EKE1450-3

TSP 75cm Coated Capillary (Low Flow) 75µm

EKE1475

TSP 75cm Coated Capillary (Low Flow) 75µm (Pack of 3)

EKE1475-3

TSP 25cm Coated Capillary (Low Flow) 50µm

EKF1425

TSP – 25cm Coated Capillary (Low Flow) 5m (Pack of 3)

EKF1425-3

TSP – 50cm Coated Capillary (Low Flow) 5m

EKF1450

TSP 50cm Coated Capillary (Low Flow) 50µm (Pack of 3)

EKF1450-3

TSP 75cm Coated Capillary (Low Flow) 50µm

EKF1475

TSP 75cm Coated Capillary (Low Flow) 50µm (Pack of 3)

EKF1475-3


High Flow NaAMPS Coated Capillaries
The open format capillaries are supplied precut to the required size with the UV window correctly positioned to fit the specific instrument manufacture’s cartridge system. The capillary ends are expertly cut to ensure precise sampling.
High Flow NaAMPS Open Format Please specify both effective length and total length when ordering

Description

Cat. No.

Price (£)

  

0-35cm Coated Capillary (High Flow) 7m

EKI1125

0-35cm Coated Capillary (High Flow) 75µm (Pack of 3)

EKI1125-3

35-65cm Coated Capillary (High Flow) 7m

EKI1150

35-65cm Coated Capillary (High Flow) 7m (Pack of 3)

EKI1150-3

70-100cm Coated Capillary (High Flow) 7m

EKI1175

70-100cm Coated Capillary (High Flow) 7m (Pack of 3)

EKI1175-3

0-35cm Coated Capillary (High Flow) 5m

EKJ1125

0-35cm Coated Capillary (High Flow) 50µm (Pack of 3)

EKJ1125-3

35-65cm Coated Capillary (High Flow) 5m

EKJ1150

35-65cm Coated Capillary (High Flow) 5m (Pack of 3)

EKJ1150-3

70-100cm Coated Capillary (High Flow) 5m

EKJ1175

70-100cm Coated Capillary (High Flow) 5m (Pack of 3)

EKJ1175-3


High Flow NaAMPS Coated Capillaries – Cartridge Refit Service
Beckman format Total length is nominal length plus 7cm after detection window

Description

Cat. No.

Price (£)

  

Beckman–20cm Coated Capillary(High Flow) 75µm

EKI1225

Beckma20cm Coated Capillary(High Flow) 7m (Pack of 3)

EKI1225-3

Beckma50cm Coated Capillary(High Flow) 7m

EKI1250

Beckman–50cm Coated Capillary(High Flow) 75µm (Pack of 3)

EKI1250-3

Beckman–70cm Coated Capillary (High Flow) 7m

EKI1275

Beckma70cm Coated Capillary (High Flow) 75µm (Pack of 3)

EKI1275-3

Beckman–25cm Coated Capillary (High Flow) 5m

EKJ1225

Beckman–25cm Coated Capillary (High Flow) 5m (Pack of 3)

EKJ1225-3

Beckma50cm Coated Capillary (High Flow) 50µm

EKJ1250