A versatile injection system for flow-injection analysis.

Area of Science:

• Analytical Chemistry
• Instrumentation Science

Background:

• Flow-injection analysis (FIA) commonly uses volume-based injection systems, typically loop valves, where sample volume is fixed by valve geometry.
• Designing injection systems with a time-dependent volume factor is less common, potentially limiting flexibility and precision.

Purpose of the Study:

• To introduce and evaluate an original analyser injection system capable of both volume-based and time-based sample injection.
• To compare the performance characteristics, specifically linearity and precision, of the new system using both injection techniques.

Main Methods:

• Development of a novel injection system adaptable to both loop (volume-based) and clock (time-based) injection techniques.
• System evaluation through rigorous testing of linearity and precision for both injection methods.

Main Results:

• The volume-based injection technique demonstrated excellent linearity (r = 0.999 to 1.000) with average precision (CV = 1.04% to 1.51%).
• The time-based injection technique exhibited superior performance with perfect linearity (r = 1.000) and enhanced precision (CV = 0.73% to 1.30%).

Conclusions:

• The developed injection system effectively accommodates both volume-based and time-based injection methods.
• The time-based injection technique is recommended due to its superior precision and overall practicability for flow-injection analysis.