Extraction methods solid-phase

Prepai ative isolation of nonvolatile and semivolatile organic compounds fractions (hydrophobic weak acids, hydrophobic weak bases, hydrophobic neutrals, humic and fulvic acids) from natural and drinking waters in optimal conditions was systematically investigated by solid-phase extraction method with porous polymer sorbents followed by isolation from general concentrate of antropogenic and/or toxic semivolatile compounds produced in chlorination and ozonation processes. 

Extraction of lyophilized protein powder by w/o-ME solution (solid-phase extraction method, SPE). 

Hennion M., 1999. Solid-phase extraction Method development, sorbents, and coupling with liquid chromatography. J Chromatogr A 856 3. 

The biological applications of NMR include the study of the structure of macromolecules such as proteins and nucleic acids and the study of membranes, and enzymic reactions. Newer methods and instruments have overcome, to a large extent, the technical difficulties encountered with aqueous samples and the analysis of body fluids is possible, permitting the determination of both the content and concentration of many metabolites in urine and plasma. NMR is not a very sensitive technique and it is often necessary to concentrate the sample either by freeze drying and dissolving in a smaller volume cm- by solid phase extraction methods. 

Z. Kuklenyik, X. Ye, J.A. Reich, L.L. Needham and A.M. Calafat, Automated online and off-line solid-phase extraction methods for measuring isoflavones and lignans in urine. J. Chromatogr. Sci. 42 (2004) 495-500. 

Chen XH, Franke JP, Ensing K, Wijsbeek J, De Zeeuw RA. 1993. Pitfalls and solutions in the development of a fully automated solid-phase extraction method for drug screening purposes in plasma and whole blood. J Anal Toxicol 17 (7) 421-426. 

When colours are added to a food system, their characterisation is often more difficult due to interferences from other materials in the food or difficulty with their extraction from the food. This is particularly the case for high-protein foods, which bind colours very tightly and can make their quantitative analysis very difficult. However, analysis for azo-dyes in soft drinks is generally straightforward using modern methods. There is less interference than in other food systems and as the colours are already in solution, and not bound to other materials, this makes the analysis easier. In some cases, the colours can be analysed without prior concentration and in others they have to be concentrated by solid-phase extraction methods, for example, Ci8 cartridges followed by elution with a small volume of methanolic ammonia. 

Table 9 Limits of quantification for PFAs based on ion-pairing and solid-phase extraction methods ...

Shiva Kesava Raju, Ch. Subramanian, M.S. Sequential separation of lanthanides, thorium and uranium using novel solid phase extraction method from high acidic nuclear wastes, J. Hazard. Mater. 145 (2007) 315-322. 

M.-C. Hennion, Solid-phase extraction method development, sorbents and coupling with liquid chromatography , J. Chromatogr. 856 3-54 (1999). 

H. Svennberg and P.-O. Lagerstrom, Evaluation of an on-line solid-phase extraction method for determination of almokalant, an antiarrhythmic drug, by liquid chromatography , J. Chromatogr. B 689 371 -377 (1997). 

Latif, E., A.K. Aslihan, and S. Mustafa. 2008. Solid phase extraction method for the determination of iron, lead and chromium by atomic absorption spectrometry using Amberite. J. Hazard. Mater. 153 454-461. 

Nichkova, M. and M.R Marco. 2005. Development and evaluation of C18 and immunosorbent solid-phase extraction methods prior to immunochemical analysis of chlorophenols in human urine. Anal. Chim. Acta 533 67-82. 

Alonso, M.C. and D. Barcelo. 2002. Stability study and determination of benzene- and naphthalenesul-fonates following an on-line solid-phase extraction method using the new programmable field extraction system. Analyst 127 472-279. 

Wolfe, K.A., Breadmore, M.C., Ferrance, J.P., Power, M.E., Conroy, J.F., Norris, P.M., Landers, J.P., Toward a microchip-based solid-phase extraction method for isolation of nucleic acids. Electrophoresis 2001, 23, 727-733. 

Traditionally thin-layer chromatography and column chromatography methods for tocol separation and quantification have been employed (Abidi, 2000) however, most analysts now prefer solid-phase extraction methods (as described in the previous section) for fractionation of a... 

Fediizzi, B., Versini, G., Lavagnini, I., Nicolini, G., and Magno, F. (2007). Gas chromatography-mass spectrometry determination of 3-mercaptohexan-l-ol and 3-mercaptohexyl acetate in wine A comparison of headspace solid phase microextraction and solid phase extraction methods. Anal. Chim. Acta, 596, 291-297. 

An HPLC-DAD method was developed for the separation and the determination of flavonoid and phenolic antioxidants in commercial and freshly prepared cranberry juice.Two sample preparation procedures were used with and without hydrolysis of the glycoside forms of flavonoids carried out by the addition of HCl in the step prior to solid-phase extraction (SPE). The flavonoid and phenolic compounds were then fractionated into neutral and acidic groups via a solid-phase extraction method (Sep-Pak Cig), followed by a RP HPLC separation with gradient elution with water-methanol-acetic acid and a detection at 280 and 360 nm. A comparison of the chromatograms obtained for extracts prepared with and without hydrolysis showed that flavonoids and phenolic acids exist predominantly in combined forms such as glycosides and esters. In a freshly squeezed cranberry juice, for instance, 400 mg of total flavonoids and phenolics per liter of sample was found, 56% of which were flavonoids. Quercetin was the main flavonoid in the hydrolyzed products, where it accounted for about 75% of the total flavonoids, while it was absent in the unhydrolyzed products. 

Try to keep samples from each cell line/tissue together. Results should be less variable if samples for each cell line/tissue are processed through the solid-phase extraction method simultaneously, usually 2 cell lines, 12 samples at one time, depending on the capacity of the extraction apparatus. 

To further validate the assay for use with environmental samples, water samples spiked with molinate were extracted and analyzed by ELISA and GC. Recovery comparisons were made between ELISA and GC for both liquid-liquid and solid phase extraction methods. Recoveries were greater than 90 for levels as low as lppb for all analysis and extraction method comparisons (23.). This study also described the utility and compatibility between solid phase extraction and ELISA for measuring low concentrations of molinate. As much as 10 acetonitrile/propylene glycol (1 1) or 5 methanol had no effect on the molinate assay. Details of this study were reported by Li et al. (38). 

Busto, O., Guasch, J. and Borrull, F. (1995) Improvement of a solid-phase extraction method for determining biogenic amines in wines,/. Chromatogr. A, 718, 309-317. 

Ferreira, V., Sharman, M., Cacho, J.F. and Dennis, J. (1996) New and efficient microextraction/solid-phase extraction method for the gas chromatographic analysis of wine volatiles,/. Chromatogr. A, 731, 247-259. 

Lindstrom, A., Albertsson, A.C. and Hakkarainen, M. (2004) Development of a solid-phase extraction method for simultaneous extraction of adipic acid, succinic acid and... 

The use of the Solid Phase Extraction Method has been concentrated mainly in the study of aldehydes and ketones of bitumens. Benzaldehydes, naphtaldehydes, fenilacetaldehydes, acetophenones, acetonaphtones, indanones, tetralones and aliphatic ketones were isolated from the Irati oil shale by using this method (24, 26). 

TD Parker, DT Rossi, DS Wright. Design and evaluation of an automated solid-phase extraction method-development system for use with biological fluids. Anal Chem 68 2437-2441, 1996. 

YF Cheng, UD Neue, LJ Bean. Straightforward solid-phase extraction method for the determination of verapamil and its metabolite in plasma in a 96-well extraction plate. J Chromatogr 828 273—278, 1998. 

DT Rossi. Automating solid-phase extraction method-development for biological fluids trends and applications in bioanalysis, LC-GC 17 S4—S8, 1999. 

---