Extraction technique identification

This procedure was compared with sequential extractive techniques employing alkaline hydrolysis of dried plant tissue followed by extraction of the acidified mixture with ethyl acetate. Fractions were individually evaluated for phytotoxic properties. Selected fractions from those showing a positive response were analyzed by gas-liquid chromatography. Structural identification and characterization of the individual components in these selected fractions were accomplished by gas chromatography-mass spectrometry. 

Dye identification is of great interest in textile studies. The classical procedure requires a hydrolysis step and other extraction techniques, followed by identification of the individual compounds present after separation by a chromatographic technique, e.g. high-performance liquid chromatography [Novotna et al. 1999, Szostek et al. 2003]. However, ToF-SIMS can be an alternative method, avoiding the phase of extraction which is always a time consuming and delicate step because of the possible destruction of the molecular structure of the sample [Ferreira et al. 2002]. The development of ToF-SIMS for dye detection has been reported in different studies. 

Tan [71] devised a rapid simple sample preparation technique for analysing polyaromatic hydrocarbons in sediments. Polyaromatic hydrocarbons are removed from the sediment by ultrasonic extraction and isolated by solvent partition and silica gel column chromatography. The sulphur removal step is combined into the ultrasonic extraction procedure. Identification of polyaromatic hydrocarbon is carried by gas chromatography alone and in conjunction with mass spectrometry. Quantitative determination is achieved by addition of known amounts of standard compounds using flame ionization and multiple ion detectors. 

Astatine, 6 207-223, 31 43-88 as astatate ion, 6 219-220 as astatide ion, properties of, 6 217-218 biochemical compounds of, 6 222 biochemical fate, 31 78 biological behavior, 6 222 31 77-78 biomedical applications, 31 79-83 therapeutic studies, 31 80-81 chemical properties of, 6 216 diatomic, 31 50 distallation, 31 47-48 elementary, 6 218-219 embryotoxicity, 31 78 extraction techniques, 31 47 identification, 31 49 in intermediate oxidation state, 6 219 iodide, 6 218-219 isotopes, 31 43-49 decay, 31 44 half-lives, 31 44 decay and half-lives of, 6 210 experimental methods for, 6 213-216 production and measurement of, 6 209-216... 

Solvent extraction of the sample is also frequently used in the analysis of particulate matter. Through the appropriate choice of solvents, the organics can be separated into acid, base, and neutral fractions, polar and nonpolar fractions, and so on. This grouping of compounds according to their chemical properties using extraction techniques simplifies the subsequent analysis. Each fraction can then be analyzed by GC-MS, with the GC retention time and the mass spectrum used for identification and measurement. 

Therefore, a mild and quick extraction technique is necessary to exclude the preparation of artifacts. The carotenoid stereoisomers can be quantitatively analysed, employing MSPD extraction, from plant material, as well as from serum samples, using on-line SPE without any isomerisation or oxidation of the carotenoids. The extraction step is coupled to the separation and identification steps. Here, LC-NMR hyphenation, employing C30 stationary phases, is suitable for unambiguous distinction between all of these stereoisomers. 

Terrestrial materials (river sediments, lake sediments, and urban particulate matter) appear to have between 50% and 70% exchangeable Pb and Zn while marine sediments contain very little exchangeable metal but appreciably more reducible and much more residual Pb and Zn (Kersten and Forstner, 1995). This may not be too surprising as exchangeable metals are released once freshwater mixes with salt water and redistribution in the marine environment results in some precipitated phases (carbonates, Fe/Mn oxyhydroxides) and the relative increase in the lithogenic fraction. In future, the solid-phase identification techniques should be used to classify the sediments that are to be subjected to selective extraction techniques for the purpose of understanding the heavy metal phase associations. 

In this review we have summarized the results obtained by different chromatographic techniques and a variety of sample preparation methods for the analysis of antioxidants in polymers and in solutions. Efficient techniques including liquid and gas chromatography, mass spectrometry, traditional low pressure extraction techniques and newer high pressure techniques have been developed. These have made possible the accurate quantification and identification of antioxidants. The newer techniques offer versatile tools for further developments in this area of polymer analysis. 

In diagnostic clinical medicine, DNA identification has been applied to investigations of patient tissue specimens obtained during biopsies or autopsies. Because of imaginative adaptations of DNA extraction techniques, the DNA contained in slides and preserved tissue specimens can now be investigated for evidence of infectious or genetic diseases. For example, in situ DNA hybridization is an ultrasensitive technique in which specific DNA probes are applied directly to tissue embedded in paraffin. (Paraffin-embedded tissue specimens are used in microscopic studies. Such slides can be stored... 

Identification of Volatile Compounds in Shiitake Mushrooms Using Modern Extraction Techniques... 

N. Trautmann, N. Kaffrell, H. W. Beuch, H. Folger, G. Herrmann, D. Hubscher and H. Ahrens, Identification of Short-lived Isotopes of Zirconium, Niobium, Molybdenum, and Technetium in Fission by Rapid Solvent Extraction Techniques, RadiocUm. Acta 18 (1972) 86. 

Because SFE can provide much higher selectivity than conventional extraction methods, usually the SFE processes produce far less impurities coextracted with the active compounds. Pure active compounds can be easily isolated from the SFE produced herbal extracts using HPLC for medicinal studies. This green extraction technique provides an efficient way of obtaining active compounds from herbs with minimum waste production and appears attractive for manufacturing high quality herbal products and for isolation and identification of active natural products from herbs and plants in general. 

The search of adequate extraction techniques allowing the identification and quantification of wine volatile compounds has attracted the attention of many scientists. This has resulted in the availability of a wide range of analytical tools for the extraction of these compounds from wine. These methodologies are mainly based on the solubility of the compounds in organic solvents (liquid-liquid extraction LLE, simultaneous distillation liquid extraction SDE), on their volatility (static and dynamic headspace techniques), or based on their sorptive/adsorptive capacity on polymeric phases (solid phase extraction SPE, solid phase microextraction SPME, stir bar sorptive extraction SBSE). In addition, volatile compounds can be extracted by methods based on combinations of some of these properties (headspace solid phase microextraction HS-SPME, solid phase dynamic extraction SPDE). 

The concentrations of individual PAH in water systems range from less than 1 ppt (pg per g) in pure ground water supplies to greater than 1 ppm (pg per g) in heavily contaminated sewage. Therefore, some preconcentration and extraction techniques are required to raise the concentrations to levels at which identification and quantitative analysis are possible. Because PAHs may only represent as little as 0.01% of the total organic fraction present in the water sample, the analytical scheme must be devised so that the PAHs can be analyzed without the interference from the other pollutants. Since the concentrations are so low, serious errors may occur from losses or contamination during sampling or the analytical... 

Hummel, Susanne. Ancient DNA Typing Methods, Strategies, and Applications. New York Springer, 2003. A manual for the analysis of ancient and degraded DNA. Includes information on extraction, techniques, and applications, including identification of objects, kinship, and population genetics. 

Several reviews covering different aspects of bile acid analysis have appeared in recent years (1-15). These articles cover a wide range of techniques with particular emphasis on thin-layer and gas chromatography. In this chapter we will try to present established methods for bile acid analysis as they can be combined to form a complete analytical procedure, including extraction, purification, identification, and quantitation. It has not been possible to include all methods and the various modifications of standard procedures that have been published. References to most of these can be found in the reviews (1-15). Early development in the field is described in Sobotka s books on bile acids and steroids (16, 17). Whenever equally efficient or similar methods exist we have generally preferred to describe those of which we have personal experience. Many of the techniques used for bile acids are similar to those used in steroid analysis and advance in this area is highly relevant for workers in the bile acid field. 

Entry Matrix Oleuropein derivative Quantity range (g/Kg matrix) Extraction technique Separation technique Identification technique... 

The methods of separation and identification of multicomponent polymers are far different from the methods described previously for the statistical type of polymer. First, only the blends are separable by extraction techniques. The remainder are bound together by either chemical bonds or interpenetration. The interpenetrating polymer networks and the conterminously grafted polymers are insoluble in all simple solvents and do not flow on heating. The graft and block copolymers, on the other hand, do dissolve and flow on heating above T/and/or Tg. 

The extraction techniques employed will include solvent dissolution and extraction, centrifugation, polymer precipitation, filtration and ashing. Details will be given of the identification of these fractions using IR spectroscopy, pyrolysis/GC, HPLC, mass spectrometry and NMR spectroscopy, often after further separation using either specific solvents or TLC [21]. All IR spectra are recorded over the region 4000-667 cm (2.5-15.0 xm). 

Acidify the aqueous phase D, remaining after the removal of alcohols (see above) with concentrated hydrochloric acid and extract the liberated thioacid with diethyl ether. Liquid - liquid extraction for 4 hours produces more material, but shaking with 50 cm of diethyl ether for about 1 min normally gives enough extract for identification. Because of partial decomposition of the thioacid during the foregoing saponification, sulphides are produced and the above acidification and extraction should be carried out in a fiime cupboard. The ether extract can be evaporated to dryness on a water bath md examined by infrared or nuclear magnetic resonance spectroscopy or by both techniques, but, because of partial decomposition a better way of identification at least for the thioacid, is as follows ... 

The continuous advances in instrumental techniques for organic compound analysis enable us to be rigorous in the analysis of carotenoid pigments. The following sections describe the main stages in the procedures of extraction, isolation, identification, and quantification of carotenoid pigments in foods of plant and animal origin. 

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