An in-house made autosampler for capillary electrophoresis

Area of Science:

• Analytical Chemistry
• Instrumentation

Background:

• Capillary electrophoresis (CE) instruments are increasingly customized for affordability and versatility.
• Traditional manual injection methods in CE are prone to errors, necessitating automation for reproducible quantitative analysis.
• Existing automation efforts improve precision but often still require manual sample handling.

Purpose of the Study:

• To design, optimize, and test a compact, in-house built autosampler for capillary electrophoresis (CE).
• To achieve fully automated sample analysis sequences, minimizing user intervention.
• To leverage Open-Source Hardware (OSH) for a customizable and adaptable CE system.

Main Methods:

• Developed a compact autosampler (26 x 9 x 9 cm) using Open-Source Hardware (OSH) principles.
• Integrated hydrodynamic pressure injection from six vials and automatic capillary rinsing.
• Coupled the autosampler to a custom-built CE instrument with a contactless conductivity detector (C4D).

Main Results:

• Achieved a precision better than 2.4% for peak areas in inorganic cation measurements.
• Demonstrated automated analysis of mineral water samples with accuracy comparable to published methods.
• The in-house OSH autosampler performed on par with commercial CE systems.

Conclusions:

• Automated analysis sequences can be successfully run using an in-house-built CE autosampler.
• The OSH approach facilitates system upgrades, feature integration, and adaptability to new requirements.
• This research provides a cost-effective and flexible solution for automated CE analysis.