Dead volume-free flow splitting in capillary electrophoresis

Area of Science:

• Analytical Chemistry
• Separation Science

Background:

• Dual detection concepts (DDCs) in capillary electrophoresis (CE) often require nondestructive detectors.
• Linear detector arrangements are not feasible when both detectors are destructive, limiting CE DDC development.

Purpose of the Study:

• To develop and validate a novel concept for splitting the CE stream to enable parallel positioning of two destructive detectors.
• To characterize the suitability of commercially available T- and Y-shaped flow splitters (FSs) for CE DDCs.

Main Methods:

• Utilized T- and Y-shaped flow splitters (FSs) to divide the CE effluent.
• Employed a UV detector (UV) and a Charged Aerosol Detector (CAD) for characterization.
• Employed a model system with an acetonitrile-based background electrolyte and two model analytes: (ferrocenylmethyl)trimethylammonium iodide and caffeine.

Main Results:

• Flow splitters achieved an approximate 50% split ratio for both T- and Y-shaped configurations.
• No significant peak broadening was observed when using FSs, as evaluated by CE-CAD.
• Limits of Detection (LODs) remained unchanged before and after the FSs.
• The FS approach demonstrated flexibility, allowing the use of capillaries with varying inner diameters (25-75 µm).

Conclusions:

• Commercially available flow splitters are suitable for enabling dual destructive detection in CE.
• The developed FS concept overcomes previous limitations, expanding possibilities for advanced CE detection strategies.
• This approach offers a flexible and effective solution for parallel destructive detection in CE applications.