The challenge for the future was defined by the Brundtland Commission (1987) and by the Rio Declaration (1992), in which the fundamental principles for achieving a sustainable development were provided. Sustainable chemistry can be defined as the contribution of chemistry to the implementation of the Rio Declaration. This thesis shows how Pressurized Fluid Extraction (PFE) can be utilized in chemical analysis, and how this correlates to Green Chemistry.The reliability and efficiency of the PFE technique was investigated for a variety of analytes and matrices. Applications discussed include: the extraction of the antioxidant Irganox 1076 from linear low density polyethylene, mobile forms of phosphorus in lake sediment, chlorinated paraffins from source-separated household waste, general analytical method for pesticide residues in rape seed, total lipid content in cod muscle, and squalene in olive biomass. Improved or comparable extraction yields were achieved with reduced time and solvent consumption. The decrease in use of organic solvents was 50-90%, resulting in minimal volatile organic compounds emissions and less health-work problem. Due to higher extraction temperatures and more efficient extractions, the selection of solvent is not as important as at lower temperatures, which makes it possible to choose less costly, more environmentally and health beneficial solvents. In general, extraction times are reduced to minutes compared to several hours. As a result of the very short extraction times, the amount of co-extracted material is relatively low, resulting in fewer clean-up step and much shorter analysis time. Selective extractions could be obtained by varying the solvent or solvent mixture and/or using adsorbents.In this thesis, the PFE technique was compared to the twelve principles of Green Chemistry, and it was shown that it follows several of the principles, thus giving a major contribution to sustainable chemistry.
Contents
1 INTRODUCTION
2 THE EXTRACTION PROCESS
2.1 EXTRACTION STRATEGY
2.2 EXTRACTION BY HIGH DIFFUSION FLUIDS
2.3 TECHNIQUES USING HIGH DIFFUSION FLUIDS
2.3.1 Supercritical fluid extraction
2.3.2 Microwave assisted extraction
2.3.3 Pressurized fluid extraction
2.3.4 Subcritical water extraction
3 PRESSURIZED FLUID EXTRACTION IN CHEMICAL ANALYSIS
3.1 PFE THEORY
3.2 PFE INSTRUMENTATION
3.3 POSSIBILITIES AND LIMITATIONS OF PFE
3.3.1 The solvent effect – the main advantage
3.3.2 The hotter the better?
3.3.3 Speed in PFE
3.3.4 Particle size matters
3.3.5 Pressure has little effect
3.3.6 Selective extractions – by adsorbents or solvent choice
3.3.7 Recovery and precisio
4 CONCLUSIONS
4.1 DOES THE PFE TECHNIQUE OBEY THE TWELVE PRINCIPLES OF GREEN CHEMISTRY?
5 DISCUSSION AND FUTURE ASPECTS
6 ACKNOWLEDGEMENTS
7 SUMMARY IN SWEDISH
7.1 BAKGRUND
7.2 DENNA AVHANDLING
7.3 SAMMANFATTNING
8 REFERENCES
Author: Waldebäck, Monica
Source: Uppsala University Library
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