Title page for ETD etd-06062008-151912
|Type of Document
||Lancaster, Edwin Dean
||Investigation of the supercritical fluid extraction and detection of metals in contaminated soils
|Long, Gary L.
|Anderson, Mark R.
|Dietrich, Andrea M.
|Tissue, Brian M.
- soil analysis
- supercritical fluid extraction
- microwave induced plasma
- on-line determinations
|Date of Defense
In this work the Supercritical Fluid Extraction (SFE) and detection of sorbed metals
in contaminated soils is explored. Iron containing samples were spiked onto sea sand and
extracted with Supercritical Fluid CO2. On-line detection was accomplished by
decompressing the SF-CO2 and analyte into a microwave induced plasma, whereby the
resulting Iron atomic emission signal was quantified. This dissertation reports the first
successful coupling of SFE and Microwave Induced Plasma - Atomic Emission Detection
(MIP-AED) for the on-line analysis of sorbed metal contaminants. The on-line analysis was
accomplished with a novel SFE-MIP interface design.
Experiments involving the on-line extraction and detection of ferrocene spiked sea
sand were very promising, in that unity of extraction and detection was achieved with this
nonpolar compound. Percent recovery was greatly reduced when the on-line extraction of
Iron III Trifluoroacetylacetonate (FeTFA) was attempted. Off-line extraction studies were
performed to establish the optimum conditions necessary to effect the SFE of the following
Iron III complexes: Iron III Acetylacetonate (FeAcac) and Iron III
Trifluoroacetylacetonate. The greatest recovery (55.85 0/0) was achieved with Supercritical
Fluid-C02 under the following conditions: 60°C, 150 atm, 20 minute static extraction
followed by 20 minute dynamic extraction. The extraction vessel contained 0.250 mg iron
complex, 20 μL HPLC grade methanol, and 20 μL deionized water. Trapping of the analyte
was achieved by decompressing the SF-C02 and analyte in 10 mL of HPLC grade methanol
held at O°C.
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