Extraction technique for determination

JF Gregory, R Engelhardt, SD Bhandari, DB Sartain, SK Gustafson. Adequacy of extraction techniques for determination of folate in foods and other biological materials. J Food Comp Anal 3 134— 144, 1990. 

Reardcm, M., and W. A. MacCrehan. "Developing a Quantitative Extraction Technique for Determining the Organic Additives in Smokeless Handgun Powder." Jcmmal cf Forensic Sciences 46 (2001), 802-807. 

Lee, S.N., Kim, N.S., and Lee, D.S. 2003. Comparative study of extraction techniques for determination of garlic flavor components by gas chromatography-mass specirometry. Anal Bioanal Chem 577(4) 749 756. 

Another difference between determinative and confirmatory method trial procedures is the way in which sample extracts are prepared for analysis. Most current methods submitted for review use the same sample extraction technique for both the determinative and confirmatory procedures. In those cases where the same extraction technique is used, the sponsor may provide the prepared extract to the FDA laboratory for analysis. Any problems with the extraction procedure will have been corrected during the determinative method trial. 

Table 3.5 Scientific publications on extraction techniques for the qualitative and quantitative determination of additives and additive classes of Appendix II...

Soini, H.A., Bruce, K.E., Wiesler, D., David, F., Sandra, P. and Novotny, M.V. (2005) Stir bar sorptive extraction a new quantitative and comprehensive sampling technique for determination of chemical signal profiles from biological media J. Chem. Ecol., 31, 377-392. 

Martens D, Gfrerer M, Wenzl T, Zhang A, Gawlik BM, Schramm K-W, Lankmayr E, Kettrup A. Comparison of different extraction techniques for the determination of polychlorinated organic compounds in sediment. Anal. Bioanal. Chem. 2002 372 562-568. 

Miege C, Dugay J, Hennion MC. Optimization, validation and comparison of various extraction techniques for the trace determination of polycyclic aromatic hydrocarbons in sewage sludges by liquid chromatography coupled to diode-array and fluorescence detection. J. Chromatogr. A 2003 995 87-97. 

Hcxanc can be determined in biological fluids and tissues and breath using a variety of analytical methods. Representative methods are summarized in Table 6-1. Most methods utilize gas chromatographic (GC) techniques for determination of -hexane. The three methods used for preparation of biological fluids and tissues for analysis are solvent extraction, direct aqueous injection, and headspace extraction. Breath samples are usually collected on adsorbent traps or in sampling bags or canisters prior to analysis by GC. 

Bierl [28] has described a procedure based on the micro-steam distillation and extraction technique for recovery and determination of low and medium-boiling chlorinated organic compounds. Recoveries of around 90%... 

A bibliographic search has shown that the majority of the HPLC techniques for determining OPPs and OCPs have been applied to the determination of residues in surface, ground- and drinking water. Table 5 lists pesticides determined, extraction and cleanup methods used, HPLC conditions, contaminated matrix and analyte detection limits taken from the literature for water, animal tissues, milk, fruit and vegetables, and cereals. The majority of the studies were done on spiked samples, and in the best of cases there were few real samples analyzed. 

Thermal desorption mass spectrometry is a rapid technique for determining oil in soils and sediments [ 33 ]. This method exhibited lower analytical variance compared to Soxhlet extraction, i.e., followed by conventional analysis. The analysis time for wet soil samples was about 20 minutes. 

Since the mixing-cell experiments were conducted with fresh or slightly weathered granite surfaces, techniques for determining sorption by carbonates and organic compounds were omitted. Using extraction techniques to determine radionuclide sorbed by... 

Pic6, Y., M. Fernandez, M.J. Ruiz, et al. 2007. Current trends in solid-phase-based extraction techniques for the determination of pesticides in food and environment. J. Biochem. Biophys. Methods 70 117-131. 

To 100 ml of sample 10 ml of 1M ammonium tartrate is added and the pH of the solution is adjusted to 6.0 0.5 by adding dilute ammonium hydroxide or tartaric acid solution as necessary. Transfer the solution to a 150 ml separatory funnel and add 10 ml of extractant solution. Shake for one minute then allow to stand for three to five minutes. Withdraw the organic layer and store in stoppered tubes prior to analysis. The APHA [8] use a similar extraction technique for the determination of beryllium and aluminium in water employing a nitrous oxide flame in the subsequent atomic absorption analysis, and using MIBK as a solvent. 

Brooks et al. [36] pioneered solvent extraction for seawater with an APDC—MIBK extraction technique for the determination of six elements in seawater by flame AAS. However, the metal complexes extracted into... 

Zinc is used in ointments and eye-lotions and is a constituent of different forms of insulin. In the former type of applications zinc oxide, zinc stearate and zinc undecanoate may be encountered in a variety of creams, ointments and pastes. Moody and Taylor [104] dissolved the residue from such samples after ether extraction (lg in 5 ml ether) in concentrated hydrochloric acid. After dilution, the determination can be completed at 213.9 nm in the air/acetylene flame where interferences are not normally encountered. Various analytical techniques for determining zinc in insulin injections have been critically compared [105] atomic absorption was preferred as being accurate, fast and precise. Spielhotz and Toralballa [106] reported a method capable of determining low levels of zinc in insulin. The sample (5 mg) was suspended in water (10 ml), 1 drop of 6M hydrochloric acid was added to effect dissolution. After making up to 50 ml the determination was completed using an air/acetylene flame. Alternatively protamine insulin solution (1 ml) may be diluted to 50 ml after the addition of 1 drop of acid. 

Walther J. V. and Orville P. M. (1983) The extraction-quench technique for determination of the thermodynamic properties of solute complexes. Application to quartz solubility in fluid mixtures. Am. Mineral. 68, 731-741. 

H. Agemian, A. S. Y. Chau, Evaluation of extraction techniques for the determination of metals in aquatic sediments. Analyst, 101 (1976), 761-767. 

Most polymer characterization is accomplished with H and NMR although N, F, Si, and NMR are also routinely used. H NMR is most commonly used because it is present in most chemical structures, has 100% natural abundance and a high gyromagnetic ratio, making it the most sensitive of all the NMR observable nuclei to detect. Moreover, because of its fast relaxation and the ability to extract information from spin-spin coupling constants, H NMR is one of the most useful techniques for determining chemical structure. However, because of its small chemical shift range (only 10 ppm) and the complexity of each proton resonance, severe peak overlap occurs for H atoms situated in similar chemical environments. 

The phosphomolybdenum blue has been applied in automatic determination of Si in natural waters [82], industrial solutions [83], as well as in the flow injection technique for determination of silicon in sea water [84], soil extracts [67,85], and glass [86]. 

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