Supercritical fluid extraction spectrometry

In order to reduce or eliminate off-line sample preparation, multidimensional chromatographic techniques have been employed in these difficult analyses. LC-GC has been employed in numerous applications that involve the analysis of poisonous compounds or metabolites from biological matrices such as fats and tissues, while GC-GC has been employed for complex samples, such as arson propellants and for samples in which special selectivity, such as chiral recognition, is required. Other techniques include on-line sample preparation methods, such as supercritical fluid extraction (SFE)-GC and LC-GC-GC. In many of these applications, the chromatographic method is coupled to mass spectrometry or another spectrometiic detector for final confirmation of the analyte identity, as required by many courts of law. 

FIG. 17 Ion pair/supercritical fluid extraction (SFE) and derivatization gas chromatography-mass-spectrometry (GC-MS). 

Pressurized Fluid Extraction followed by Gas Chromatography/Mass Spectrometry (PFE-GC/MS) On-line Supercritical Fluid Extraction - Gas Chromatography/Mass Spectrometry (SFE-GC/MS)... 

Thermogravimetric methods such as pyrolysis gas chromatography-mass spectrometry have been used to characterize hydrocarbon sludges from polluted soils [10]. In combination with conventional extraction and supercritical fluid extraction followed by gas chromatography-mass spectrometry, over 100 constituents were identified in soil samples. Thermogravimetric analysis-mass spectrometric results distinguished between the release of a component by thermosorption and by pyrolysis. 

The method based on immunosorbents coupled on-line with liquid chromatography-atmospheric pressure chemical ionization mass spectrometry [109], discussed in section 9.4.2.1, has been applied to the determination of substituted urea type herbicides. Supercritical fluid extraction with methanol modified carbon dioxide has been applied to the determinants of sulfonyl urea herbicides in soil [261],... 

Supercritical fluid extraction followed by high-performance liquid chromatography-mass spectrometry has been used to determine Atrazine and its metabolites in soil [22],... 

GC = gas chromatography GPC = gel permeation chromatography ECD = electron capture detector MS = mass spectrometry MSD = mass selective detector SFE = supercritical fluid extraction TLC = thin layer chromatography... 

Spell JC, Srinivasan K, Stewart JT, Bartlett MG. 1998. Supercritical fluid extraction and negative ion electrospray liquid chromatography tandem mass spectrometry analysis of phenobarbital, butalbital, pentobarbatal and thiopentoal in human serum. Rapid Commun Mass Spectrom 12 890. 

CZE = capillary zone electrophoresis EC = electrochemical detector GC = gas chromatography HCD = Hall conductivity detector HPLC = high performance liquid chromatography IDMS = isotope dilution mass spectrometry MS = mass spectrometry RSD = relative standard deviation SEE = supercritical fluid extraction SPE = solid phase extraction UV = ultraviolet absorbance detection... 

Wong, D.C.L. van Compemolle, R. Nowlin, J.G. O Neal, D.L. Johnson, G.M. Use of supercritical fluid extraction and fast ion bombardment mass spectrometry to identify toxic chemicals from a refinery effluent adsorbed onto granular activated carbon. Chemosphere 1996, 32, 621. 

RJ Argauer, KY Eller, MA Ibrahim, RT Brown. Determining propoxur and other carbamates in meat using HPLC fluorescence and gas chromatography/ion mass spectrometry after supercritical fluid extraction. J Agric Food Chem 43 2774-2778, 1995. 

K. Hartonen and M.-L. Riekkola, Detection of /3-blockers in urine by solid-phase extraction-supercritical fluid extraction and gas chromatography-mass spectrometry , J. Chromatogr. 676 45-52 (1996). 

R. Fuoco, A. Ceccarini, M. Onor and S. Lottici, Supercritical fluid extraction combined online with cold-trap gas chromatography/mass spectrometry , Anal. Chim. Acta 346 81-86(1997). 

Ultrasonic extraction, methanol extraction [147] and supercritical fluid extraction have all been applied to the extraction of or the determination of volatile organic compounds [121,122] in soils. However, methods based on headspace analysis or on mass spectrometry are now the methods of choice. 

Supercritical Fluid Extraction (SCFE)—Direct Fluid Injection Mass Spectrometry (DFI-MS)... 

Field, J.A., D.J. Miller, T.M. Field, S.B. Hawthorne, and W. Giger. 1992. Quantitative determination of sulfonated aliphatic and aromatic surfactants in sewage sludge by ion-pair/supercritical fluid extraction and derivatization gas chromatography / mass spectrometry. Anal. Chem. 64, 3161-3167. 

Notes LOD, limit of detection MeOH, methanol EtOH, ethanol ACN, acetonitrile MTBE, methyl tert-butyl ether DCM, dichloromethane THF, tetrahy-drofuran KOH, potassium hydroxide SFE, supercritical fluid extraction MS, mass spectrometry HPLC, high-performance liquid chromatography DAD, diode array detector PDA, photodiode array detector FD, fluorescence detector ECD, electrochemical detector ESI, electrospray ionization APCI, atmosphere pressure chemical ionization TLC, thin layer chromatography FAB, fast atom bombardment NMR, nuclear magnetic resonance BHT, butylated hydroxytoluene SPE, solid phase extraction. 

Klejdus B, Lojkova L, Lapcik O, Koblovska J and Kuban V, Supercritical fluid extraction of isoflavones from biological samples with ultra-fast high-performance liquid chromatography/mass spectrometry. J Sep Sci 28 1334-1346 (2005). 

Figure 6.1 Bar-graph of MeHg in CRM 580. The results correspond to six replicate determinations as performed by different laboratories using various methods. MEANS indicates the mean of laboratory means with 95% confidence interval. Abbreviations-. CVAAS, cold vapour atomic absorption spectrometry CVAFS, cold vapour atomic fluorescence spectrometry ECD, electron capture detection GC, gas chromatography HPLC, high-performance liquid chromatography ICPMS, inductively coupled plasma mass spectrometry MIP, microwave induced plasma atomic emission spectrometry QFAAS, quartz furnace atomic absorption spectrometry SFE, supercritical fluid extraction.

Vela, N.P. and Caruso, J.A. (1996) Trace metal speciation via supercritical fluid extraction-liquid chromatography-inductively coupled plasma mass spectrometry. /. Anal. At. 

Shimmo, M., A. Piia, K. Hartonem, et al. 2004. Identification of organic compounds in atmospheric aerosol particles by on-line supercritical fluid extraction-liquid chromatography-gas chromatography-mass spectrometry./. Chromatogr. A 1022 151-159. 

Lee, H.B. and T.E. Peart. 2002. Determination of bisphenol A in sewage effluent and sludge by solid-phase and supercritical fluid extraction and gas chromatography/mass spectrometry. /. AOAC Int. 83 ... 

Alexandrou N, Miao Z, Colquhoun M, et al. 1992. Supercritical fluid extraction and cleanup with capillary GC-ion trap mass spectrometry for determination of polychlorinated dibenzo-p-dioxins and dibenzofurans in environemental samples. J Chromatogr Sci 30(9) 335-382. 

With the demonstration of supercritical fluid extraction, an obvious extension would be to extract or dissolve the compounds of interest into the supercritical fluid before analysis with SFC.(6) This would be analogous to the case in HPLC, where the mobile phase solvent is commonly used for dissolving the sample. The work described here will employ a system capable of extracting materials with a supercritical fluid and introducing a known volume of this extract onto the column for analysis via SFC. Detection of the separated materials will be by on-line UV spectroscopy and infrared spectrometry. The optimized SFE/SFC system has been used to study selected nonvolatile coal-derived products. The work reported here involved the aliphatic and aromatic hydrocarbon fractions from this residuum material. Residua at several times were taken from the reactor and examined which provided some insight into the effects of catalyst decay on the products produced in a pilot plant operation. 

ECD = electron capture detector FID = flame ionization detector GC = gas chromatography HRGC = high resolution gas chromatography LC-APCI-MS = liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry LSE = liquid-solid extraction MS = mass spectrometry PVC = polyvinyl chloride SFE = supercritical fluid extraction... 

Ramsey, E.D., Perkins, J.R., Games, D.E., and Startin, J.R. 1989. Analysis of drug residues in tissue by combined supercritical-fluid extraction-supercritical-fluid chromatography-mass spectrometry-mass spectrometry. Journal of Chromatography, 464 353-64. 

MacKay, G.A. Smith, R.M. Supercritical fluid extraction-supercritical fluid chromatography-mass spectrometry for the analysis of additives in polyurethanes. J. Chromatogr. Sci. 1994, 32, 455-460. 

Fuoco, R. Ceccarini, A. Onor, M. Lottici, S. Supercritical fluid extraction combined on-line with cold-trap gas chro-matography/mass spectrometry. Anal. Chim. Acta 1997, 346 (1), 81-86. 

R. Fuoco, P. R. Griffiths, Analysis of polychlorobyphenyls (PCBs) in contaminated soil samples by supercritical fluid extraction/supercritical fluid chromatography coupled with FT-IR spectrometry, Ann. Chim. (Rome), 82 (1992), p. 235. 

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