Comparison of extraction methods

Table 3.22 Comparison of extraction methods for polyamide samples...

Validation of extraction procedures is frequently lacking. A good assessment of quality assurance implies that the extraction recoveries are verified, e.g. by spiking of standard addition. A major drawback is that the spike is not always bound the same way as the compounds of interest. For the development of good extraction methods, materials with an incurred analyte (i.e. bound to the matrix in the same way as the unknown), which is preferably labelled (radioactive labelling would allow verification of the recovery), would be necessary. Such materials not being available, the extraction method used should be validated by other independent methods, e.g. by verification against known samples and by use of a recovery SPC chart. A mere comparison of extraction methods is no validation. 

A comparison of extraction methods for primary aromatic amines including 1,4-phenylenediamine, 2,4-diaminotoluene, benzidine, 4,4 -methylenebis (2-chloroanilme), 3,3 -dimethylbenzidine, and 3,3 -dichlorobenzidine from solid matrices was conducted. Supercritical fluid extraction (SEE) was evaluated and compared with the classical method, sonication extraction (Oost-dyk et al., 1993). 

Fawkes J, Albro PW, Walters DB, et al. 1982. Comparison of extraction methods for determination of polybrominated biphenyl residues in animal tissue. Anal Chem 54 1866-1871. 

Kim, B.-H., Lee, S.-J., Kim, H.-S., Chang, Y.-S., 2004a. Determination of polychlorinated dibenzo-p-dioxins and dibenzofurans and comparison of extraction methods for edible freshwater fish and frogs in South Korea by using a high-resolution GC/MS. Food Additives and Contaminants 21, 700-710. 

J. R. Dean, Comparison of extraction methods, in Extraction Methods for Environmental Analysis, Wiley, Chichester, West Sussex, England, 1998,... 

F. Yang, R. E. Sturgeon, S. McSheehy, Z. Mester, Comparison of extraction methods for quantitation of methionine and selenomethionine in yeast by species specific isotope dilution gas chromatography-mass spectrometry, J. Chromatogr. A, 1055 (2004), 177-184. 

Xu, Z. 2008. Comparison of extraction methods of quantifying vitamin E from animal tissues. Biores. Tech. 99 8705-8709. 

Moller, J., Stromberg, E., Karlsson, S. Comparison of extraction methods for sampling of low molecular compounds in polymers degraded during recycling. Eur Polym J 44, 1583-1593 (2008)... 

The use of SFE and MAE has been generalized to many essential oils and different samples. These techniques have improved recoveries in the determination of most organic additives, as well as permitted considerable reductions in solvent volume and extraction time. However, the comparison of extraction methods was usually reduced to relative recoveries of target analytes, ignoring important analytical parameters of the method. Selectivity is one of these, as the coextraction of other organics from the matrix usually requires a postextraction cleanup step before chromatographic analysis. There is still much effort to be carried out in this field in order to optimize the extraction of essential oils from different natural matrices. The selection of the best extraction method depends on the components to be extracted, and this is something to be carefully considered in each particular case. 

Several examples of laboratory-scale extractions follow. (1) SFE was used in a comparison of extraction methods for the determination of the apparent tannins in common beans. (2) Homogenates of shrimp meat were extracted with ethyl acetate followed by precolumn cleanup on a silica Sep-Pak cartridge to determine 4-hexylresorcinol, a processing aid. Two extraction procedures were compared to extract oil from olive foot cake with acidic hexane. An open-air method and exhaustive Soxhlet extraction with the latter removed about two times more oil. (3)... 

Comparison of Extraction Methods. Preliminary analytical results (12) indicated that our ambient-temperature tumbler sediment extraction was about as efficient for hydrocarbon recoveries as soxhlet extraction. To test the tumbler extraction performance more completely, we have compared it with an alkaline methanol reflux extraction (13) a 1 1 benzene methanol soxhlet extraction (10) and a 2 1 dichloromethane methanol (azeotrope 7.6 1) soxhlet extraction (15), using replicate analyses of the homogenized harbor sediment. 

Beard, A., Naikwadi, K., and Karasek, F. W., Comparison of extraction methods for polychlorinated dibenzo-p-dioxins and dibenzofurans in fly ash using gas chromatography-mass spectrometry,... 

Table 4. Comparison of extraction methods (Martin del Campo. 2011, Gshaedler. 2004).

The use of these alternative extraction techniques has been generahzed to many essential oils and different samples as previously mentioned. These techniques have improved recoveries in the determination of most organic additives, as well as permitted considerable reductions in solvent volume and extraction time. However, the comparison of extraction methods was usually reduced to relative... 

Peralbo-Molina, A., Priego-Capote, F., and de Castro, M.D.L. 2012. Comparison of extraction methods for exploitation of grape skin residues from ethanol distillation. Talanta, 707 292-298. 

Drawert, F., R. Tressl, G. Standt, H. Koppler, Gaschromatographischmassenspek-tometrische Differenzierung von Erbeerarten, Z. Naturforsch, 28C, p. 488, 1973. Torline, R, H.M. Ballschmieter, Volatile constituents from guava. I. A comparison of extraction methods, Lebensm. Wissen. u-Technol., 6(1), p. 32, 1973. 

Chukwumah, Y.C. et al.. Comparison of extraction methods for the quantification of selected phytochemicals in peanuts Arachis hypogaea), J. Agric. Food Chem., 55, 285, 2007. 

Table 2.5 Comparison of extraction methods for solid samples soil, sediment, fly ash, sludge and solid wastes (Oleszek-Kudlak ef al., 2007).

Larsson CM and Olsson T (1979) Firefly assay of adenine nucleotides from algae Comparison of extraction methods. Plant Cell Physiol. 20, 145-155. 

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