Extraction and isolation

After sulfuric acid work-up (accompanied by the formation of sodium sulfate), the resorcinol is extracted and isolated in a 94% yield based on y -benzenedisulfonic acid [98-48-6]. In addition to the technical complexity that goes along with the manipulation of soHds at high temperature, this process produces large amounts of salts (sulfite and sulfate salts) which economically as well as environmentally are not always desired. 

The isomeric, nonpungent 3//-azepines, isochalciporone (26) and dehydroisochalciporone (27), can also be isolated in small amounts, but appear to be artefacts produced during extraction and isolation of the very thermally labile chalciporone. 

To correlate embryonic arrests with the metabolic pathways, and especially to understand why cellular organelles first undergo chemical damages, biological investigations include evaluation of DNA, RNA, protein, glucose, lipid, and adenosine-5 -triphosphate (ATP) contents, whose fractions are extracted and isolated by modified Schneider methods. In particular,... 

Schoefs reports the particularities of extraction and isolation of pigments from different vegetables and fruits, giving practical advice on a case-by-case basis. 

SFC has played an important role in the extraction and isolation of fatty acids [355,356]. Underivatised fatty acids and methyl esters of fatty acids are surprisingly easy to elute using a bonded phase or a silica based packed column and pure C02, probably due to the long hydrocarbon tails on the molecules [357]. On the other hand, most aromatic and polysubstituted acids will not elute. Triglycerides with saturated fatty acids can be analysed faster with pSCF-ELSD than with GC-FID and do not require sample preparation [358]. Using... 

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. 

Fish. Solid biota samples, mainly fish, should be quickly killed by liquid N2 [28] or cervical dislocation [32] and kept at low temperatures (— 20°C). Some authors preferred desiccation of the sample at high temperature (70°C) [33,34] or lyophylisation [28]. The extraction and isolation steps would be combined when using lyophylisation and homogenisation, followed by a Soxhlet extraction, usually with MeOH, and a subsequent solid-phase extraction (SPE) clean-up, prior to the quantification. 

Tolls et al. [23,51] used MSPD with ion-pair liquid-liquid partitioning for the extraction and isolation of radiolabeled LAS from a freshwater... 

Compound extraction and isolation The raw propolis (155 g) was soaked in 90% aqueous ethanol (1 L) for 1 week and the extraction was repeated twice. 

Meadows, J.C. Tillitt, D.E. Schwartz, T.R. Schroeder, D.J. Echols, K.R. Gale, R.W. Powell, D.C. Bursian, S.J. 1996, Organochlorine contaminants in double-crested cormorants from Green Bay, Wisconsin 1. Large-scale extraction and isolation from eggs using semi-permeable membrane dialysis. Arch. Environ. Con. Tox. 31 218-224. 

Ether and ester yields were determined by VPC, acid yield was obtained following extraction and isolation. 

Rodrigues RAF, Foglio MA, Junior SB, Santos AS, Rehder VLG. (2006) Optimization of the extraction and isolation of the antimalarial drug artemisinin from Artemisia annua L. Quim Nova 29 368-372. 

Pistelli L, Bertoli A, Noccioli C, Mendez J, Musmanno RA, Maggio T, Coratza G. (2009) Antimicrobial activity of Inga fendleriana extracts and isolated flavonoids. Nat Prod Commun 4 1679-1683. 

Benomyl was extracted and isolated by the procedure of Austin and Briggs (7). After isolation and concentration, benomyl and its metabolites were determined colorimeCrically. 

T2. Titus, E. 0-, Isolation procedures—liquid extraction and isolation techniques. In Fundamentals of Drug Metabolism and Drug Disposition (B. N. LaDu, H. G. Mandel, and E. L. Way, eds.), pp. 419-436. Williams Wilkins, Baltimore, Maryland, 1971. 

Baxter, R.M. Bramham, J. Thomason, P.A. Downes, C.P. Carter, A.N. Characterisation of phosphatidylinositol 3-kinase in PC12 cell extracts and isolation of the enzyme from rat brain extracts. Biochem. Soc. Trans., 21, 359S (1993)... 

Collection, Extraction, and Isolation. Live specimens of S. divinorum were collected at Cerro Quemado (Sept. 3, 1979) and Cerro Rabon (March 7, 1980) in Oaxaca, Mexico. The plants were cultivated at the... 

The process of drug discovery from plants involves several steps, from plant collection and vouchering through the preparation of plant extracts to bioassay of the extracts and isolation and structure elucidation of bioactive constituents. An important aspect of this project was that it was conducted with the full informed consent not only of the government of Suriname but also of the Saramaka Maroon tribal people of our collection sites. The way this was done is important, as it sets a standard for future work of this type. 

Application of the MAS to drinking water should considerably broaden the scope of organic compounds detected and measured, relative to previously available analytical methods. This conclusion is especially true for the polar compounds of relatively low MW (<500) however, a few of these compounds are not recovered well by the MAS extraction and isolation techniques or are not gas chromatographable, even after derivatization. HPLC methods offer the most promise for separation and analysis of these compounds as well as those of high molecular weight. 

This is another alkaline-catalyzed transesterification technique. Similar to the sodium methoxide method (see Basic Protocol 2), only one step is required for the methylation reaction, followed by FAME extraction and isolation. As opposed to the sodium methoxide method, the investigator of the original publication for this method claimed that the tetramethylguanidine (TMG) works on both esterified and free fatty acids however, in the authors experience, and in published studies (see Background Information), TMG does not satisfactorily convert free fatty acids to corresponding methyl esters. 

Basic Protocol 1 Solvent Extraction and Isolation of Carotenoids F2.1.1... 

The extraction and isolation of three groups of carotenoids of different polarity are described in Basic Protocol 1. A method for prepurifying carotenoids using crystallization is described in Basic Protocol 2. Carotenoids may be purified further by chromatographic techniques (unit F2.3) and characterized (units F2.2 F2.4). Support Protocols 1 and 2 describe the preparation of the sample before extraction. This process consists mainly of removing water from the sample followed by sample grinding or homogenizing. 

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