High-pressure solvent extraction

HPSE liquid chromatography High-pressure solvent extraction ICR emission spectrometry Ion-cyclotron resonance... 

David and Seilier [1] compared the efficiencies of various extraction techniques including supercritical fluid [2], high pressure solvent and Soxhlet extraction for the removal of organophosphorus hydraulic fluids from soil. High pressure solvent extraction was at temperatures up to 200°C and pressures up to 170 bar was the favoured technique. Extraction efficiencies were similar in all three methods, but the favoured method was more rapid and cheaper to operate. 

Supercritical fluid extraction can be performed effectively with very simple systems. Figure 5 displays the basic components of an effective analytical SFE device. There are relatively few commercial suppliers of dedicated supercritical fluid extraction instrumentation. Table 7 shows the companies that promote SFE instrumentation as of the writing of this chapter. Some of the more traditional instrument manufacturers such as Hewlett-Packard (7680T SFE), Dionex (SFE 723), and Supelco (SFE-400) have discontinued their SFE lines. Dionex has invested quite heavily into high-temperature/high-pressure solvent extraction devices, and this will be described in the next section. For most purposes, inexpensive and efficient extraction units can be assembled using the basic components shown in Figure 5. 

Yes, there have been comparative studies in which the percent recovery has been measured using not only SFE but also ASE and comparing these results to percent recoveries from the more conventional Soxhlet extraction (S-LSE). Generally, these studies are done on certified reference samples or on grossly contaminated samples. We will discuss two studies from the recent analytical chemistry literature. The first study compared the efficiencies of SFE, high-pressure solvent extraction (HPSE), to S-LSE for removal of nonpesticidal organophosphates from soil (46). HPSE is very similar to accelerated solvent extraction however, we will reserve the acronym ASE for use with the commercial instrument developed by Dionex Corporation. HPSE as developed by these authors used parts available in their laboratory.. The authors compared S-LSE with SFE and HPSE for extraction of tricresyl phosphate (TCP) and triphenyl phosphate (TPP) from soil. Molecular structures for these two substances are as follows ... 

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