Split-flow injector for capillary zone electrophoresis

Area of Science:

• Analytical Chemistry
• Separation Science

Background:

• Split-flow injectors are crucial for sample introduction in capillary electrophoresis (CE).
• Common issues include sample zone broadening and interruption of applied voltage during injection.
• Existing designs often require complex manipulation or compromise separation efficiency.

Purpose of the Study:

• To describe a simple, robust split-flow injector design for capillary electrophoresis.
• To address common problems associated with conventional split-flow injection systems.
• To enhance electrokinetic injection performance by minimizing sample zone broadening.

Main Methods:

• Construction of a split-flow injector comprising a low-pressure pump, injection valve, and delivery tube.
• Integration of the separating capillary inlet within the delivery tube.
• Experimental investigation of parameters like capillary inlet position and background solution flow-rate.

Main Results:

• The described injector allows sample injection without moving the capillary inlet or interrupting voltage.
• Minimized delivery tube length and internal diameter reduce additional sample zone broadening.
• Experimental studies confirmed the influence of parameter positioning and flow-rate on performance.

Conclusions:

• The developed split-flow injector offers a simplified and effective solution for electrokinetic injection in CE.
• This design overcomes limitations of traditional injectors, leading to improved separation efficiency.
• The system's simplicity and effectiveness make it suitable for routine analytical applications.