Combined supercritical fluid extraction/supercritical fluid chromatography/Fourier transform infrared spectrometry for the analysis of polar compounds deposited on polymeric matrices

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:7243219

Yang, J

The development of methods for the analysis of polar, nonvolatile compounds deposited on polymeric substrates is described. Problems encountered included the difficulty of detecting and identifying trace levels of deposited compounds, the large interference from other extractable materials in the matrix, and the need to overcome interaction between the analytes and the matrix. Supercritical fluid extraction (SFE), supercritical fluid chromatography (SFC) permit the automated extraction, separation and identification of the analytes. The properties of supercritical fluids (SFs) were evaluated by a study of various equations of state based on the Benedict-Webb-Rubin and Van der Waals equations. The results indicated that the original Lee-Kesler and the Patel-Teja-Valderrama equations provide the most reliable pressure-volume-temperature and phase behavior, respectively. Two techniques for measuring of the signal from a flame ionization detector and one based on SFC retention times were developed. Methods for the separation of polar, nonvolatile compounds by SFC based on the results of this study were developed. Pressures up to 500 atmospheres were required for the elution of some compounds. An automated SFE/SFC interface was constructed and techniques for the extraction of relatively insoluble materials from a variety of matrices were developed. When the analytes interacted very strongly with the matrix, it was necessary to use modified CO[sub 2] as the mobile phase to increase the solubility of the analytes and to treat the substrate with methanol to overcome the interaction between the analyte and the matrix. A direct-deposition SFC/FT-IR interface was constructed. Detection limits in the low nanogram range were found. A technique based on principal components analysis were applied for distinguishing between indigenous and non-indigenous materials in paper from their SFC/FT-IR spectra. Library searching techniques for SFC/FT-IR spectra were compared.

• Research Organization: Idaho Univ., Moscow, ID (United States)
• OSTI ID: 7243219
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102* -- Chemical & Spectral Procedures
400105 -- Separation Procedures
CHROMATOGRAPHY
EXTRACTION
FOURIER TRANSFORM SPECTROMETERS
INFRARED SPECTRA
MEASURING INSTRUMENTS
POLAR COMPOUNDS
POLYMERS
SEPARATION PROCESSES
SOLVENT EXTRACTION
SPECTRA
SPECTROMETERS
SUPERCRITICAL FLUID CHROMATOGRAPHY
SUPERCRITICAL GAS EXTRACTION