Improved extraction methods

Based on the heat-induced AR principle, DNA/RNA extraction from FFPE tissues can be successfully achieved by a simple heating protocol that allows satisfactory application of molecular analysis using FFPE tissue samples housed in pathology laboratories worldwide. By a combination of improved extraction methods with various innovative techniques of molecular biology, more reliable results of molecular profiling for archival tissue are anticipated. 

New improved extraction method for madder dyes. For these investigations, the following method of extraction is recommended ... 

When we strip a red dyeing by the improved extraction method with a mixture of 10% sulfuric acid and ethyl acetate (1 1) and.the upper layer has a yellow or orange-yellow shade and the lower layer is colorless, we can assume that this is a madder dyeing. 

Even with the new, improved extraction method, we often obtain this chromatographic picture in analyzing old madder dyeings, if... 

Rubia peregrina As the new, improved extraction method was used here, the pseudopurpurin spot is most prominent, and purpurin can also be clearly identified. Alizarin is only present in traces. The red spot may be rubiadin (III), until now not mentioned in the literature as a dye in Rubia peregrina. 

Figure 3. Comparison of the old and the new (improved) extraction methods for madder dyeings and madder pigments (see page 202) by TLC. 1, and 2, extractions of a sample of the artist s pigment Rose Madder Genuine 1, extraction by the new method 2, extraction by the old method 3, pseudopurpurin (lower spot) 4, purpurin 5, alizarin.

Walters, R.R., Buist, S.C. (1998). Improved enantioselective method for the determination of the enantiomers of reboxetine in plasma by solid-phase extraction, chiral derivitization, and column-switching high-performance liquid chromatography with fluorescence detection. J. Chromatogr. A 828, 167-176. 

On-going studies to improve analytical methods for hexachloroethane and related compounds include the EPA "Master Analytical Scheme" being developed for organic compounds in water (Michael et al. 1988) and the research in supercritical fluid extraction (Lopez-Avila et al. 1991 Wieboldt et al. 1988). Research continues on improving extraction, concentration, and elution techniques, and detection devices (Eichelberger et al. 

The overall method includes sample collection and storage, extraction, and analysis steps. Sampling strategy is an important step in the overall process. Care must be taken to assure that the samples collected are representative of the environmental medium and that they are collected without contamination. There is an extensive list of test methods for water analysis (Tables 8.2, 8.3, and 8.4), which includes numerous modifications of the original methods, but most involve alternative extraction methods developed to improve overall method performance for the analysis. Solvent extraction methods with hexane are also in use. 

In conclusion, HPLC is preferred over GC for analysis of 1,2-diphenylhydrazine. Sample preservation and extraction methods need improvement. 

The ban on the use of leaded gasoline in the 1970s produced one of the most successful episodes in the search for the control of air pollutants. As already noted, the concentration of lead in the air dropped dramatically and to very low levels within a matter of years after the ban was put into place. Currently, efforts to control lead emissions focus on improving the methods used to remove lead from air and water wastes of smelters, metal processing plants, and other such plants. The most common systems currently used are variations of traditional waste control techniques in which physical devices (such as baghouses) or chemical systems (such as precipitation reactions) are used to extract particles of lead from wastes. 

J. Wieling, P.M.J. Coenegracht, C.K. Mensink, J.H.G. Jonkman and D.A. Doombos, Selection of Robust Combinations of Extraction Liquid Composition and Internal Standard Monte Carlo Simulation of Improvement of Methods with Liquid-Liquid Extraction prior to HPLC, Journal of Chromatography, 594 (1992) 45-64. 

It is very common to combine methods in obtaining aroma isolates. The simultaneous distillation/extraction method previously described is an example. Another popular combination method initially involves the solvent extraction of volatiles from a food and then high-vacuum distillation of the solvent/aroma extract to provide a fat-free aroma isolate. This technique is broadly used today to provide high-quality aroma extracts for numerous purposes. The apparatus used in solvent removal has been improved upon to reduce analysis time and efficiency the modified method is termed solvent-assisted flavour extraction (SAFE) [16]. 

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