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On the greenness of separation modes containing compressed fluids
Troy T Handlovic1, M Farooq Wahab1, Bailey C Glass1
1Department of Chemistry and Biochemistry, The University of Texas at Arlington, USA.
Analytica Chimica Acta
|November 3, 2024
Summary
Greenness evaluations of liquid chromatography (LC) methods, including supercritical fluid chromatography (SFC) and enhanced fluidity liquid chromatography (EFLC), must consider instrument cycle time. A modified Analytical Method Greenness Score (AMGS) reveals that SFC and EFLC are not always the greenest options for environmental analysis.
Area of Science:
- Analytical Chemistry
- Environmental Science
- Green Chemistry
Background:
- Liquid chromatography (LC) traditionally uses toxic organic solvents, posing environmental, health, and safety concerns.
- Supercritical fluid chromatography (SFC) and enhanced fluidity liquid chromatography (EFLC) are promoted as greener alternatives to traditional reversed-phase (RPLC) and normal-phase (NPLC) methods.
- Quantitative greenness evaluations are crucial to validate the environmental benefits of different chromatographic techniques.
Purpose of the Study:
- To quantitatively assess the
- To critically evaluate the greenness of various LC modes, including SFC and EFLC, by incorporating instrument cycle time into the assessment.
- To provide analytical chemists with a tool for selecting the most environmentally friendly separation methods.
Main Methods:
- Modification of the Analytical Method Greenness Score (AMGS) to include instrument cycle time.
- Application of the first-order optimality condition (AMGS gradient = 0) to determine optimal greenness.
- Comparative analysis of different LC modes using the modified AMGS metric.
Main Results:
- Supercritical fluid chromatography (SFC) and enhanced fluidity liquid chromatography (EFLC) are not consistently the greenest chromatographic options.
- Instrument cycle time significantly impacts the overall greenness score, altering perceptions of flow rate efficiency.
- The separation of tobacco alkaloid enantiomers demonstrated the utility of the modified metric across various retention phenomena.
Conclusions:
- The modified AMGS metric provides a practical tool for analytical chemists to assess the environmental impact of their separation methods.
- This methodology helps identify the greenest separation conditions for routine chemical analysis by considering instrument cycle time.
- Informed decisions regarding chromatographic method selection can be made to minimize environmental burden.
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