Improvement of an Automated Sample Injection System for Pillar Array Columns to Increase Analytical Reproducibility

Area of Science:

• Analytical Chemistry
• Chromatography

Background:

• Previous automatic sample injection systems for pillar array columns used autosamplers, leading to sample dilution and poor analytical reproducibility.
• The relative standard deviation (RSD) for coumarin dyes exceeded 17% in the prior system.

Purpose of the Study:

• To develop an improved sample injection system for pillar array columns that enhances analytical reproducibility.
• To overcome the limitations of sample dilution associated with autosamplers in quantitative analysis.

Main Methods:

• Replaced the autosampler with a syringe pump for sample injection.
• Filled the capillary column with sample at a constant rate to prevent dilution.

Main Results:

• The improved system using a syringe pump eliminated sample dilution.
• Achieved a significant reduction in RSD for coumarin dyes from over 17% to 1.2-1.8%.
• Demonstrated excellent analytical reproducibility for five types of amino acids, with RSDs within 3.0%.

Conclusions:

• The syringe pump-based sample injection method provides superior analytical reproducibility for pillar array columns.
• This method is suitable for simple, quantitative biological sample analyses using pillar array columns.