Phenolics test

As shown in Table IV, all phenols tested were confirmed to accelerate the conversion of phenyl benzyl ether. In this thermolysis, benzyl phenyl ether was decomposed to toluene and phenol (ca. 60%) and also isomerized to benzyl phenol (ca. 40%). 

Tests for carboxylic acids were made by paper chromatography using 95% ethanol (100 ml.) and concentrated ammonium hydroxide (1 ml.) as solvent and aqueous bromothymol blue as indicator (1). Tests for pyridines were made on their hydrochlorides using butanol-.acetic acid water (4 1 5) as solvent and ammoniacal iron chloride or cysteine-sulfuric acid as indicators. Phenol tests were made using the same solvent and ammoniacal silver nitrate as indicator. Preliminary separations by gas chromatography were attempted using a 15-foot silicone gum column and a hydrogen flame attachment. 

Two nonprescription pain relievers are available as substitutes for aspirin Ibuprofen and Naproxen. Would each of these drugs give a positive phenol test Explain your answer. What functional group is common to each of these drugs ... 

Chemical Reactions. Perform the same phenolics test with twigs of both jnvenile and adult growth forms of the same species. Use whatever species are available in your area aspen, cottonwood, red oak, willow, basswood, ash, or others. Compare the color reaction in jnvenile shoots with those in shoots of the adnlt growth form. 

The phenolic compounds, 2-chlorophenol (2-CP) and pentachlorophenol (PCP) were taken from a phenol test kit (4--4570, Supelco, Inc., Bellefonte, PA). HRP... 

Chlorinated phenolic compounds in air-dried sediments collected downstream of chlorine-bleaching mills were treated with acetic anhydride in the presence of triethylamine. The acetylated derivatives were removed from the matrix by supercritical fluid extraction (SEE) using carbon dioxide. The best overall recovery for the phenolics was obtained at 110°C and 37 MPa pressure. Two SEE steps had to be carried out on the same sample for quantitative recovery of the phenolics in weathered sediments. The SEE unit was coupled downstream with a GC for end analysis . Off-line SEE followed by capillary GC was applied in the determination of phenol in polymeric matrices . The sonication method recommended by EPA for extraction of pollutants from soil is inferior to both MAP and SEE techniques in the case of phenol, o-cresol, m-cresol and p-cresol spiked on soil containing various proportions of activated charcoal. MAP afforded the highest recoveries (>80%), except for o-cresol in a soil containing more than 5% of activated carbon. The SEE method was inefficient for the four phenols tested however, in situ derivatization of the analytes significantly improved the performance . 

Phenols in trace concentrations were derivatized by coupling with a 4-sulfobenzene-diazonium salt at pH 10.5. The azo dyes were combined with tetradecyldimethylbenzy-lammonium ions at pH 5.0 and, after SPE on a PTFE membrane filter, the end analysis was carried out by RP-HPLC with UVD at 352 nm. LOD was between 40 ppt (phenol) and 2 ppb (2,5-xylenol) for eight phenols tested. The method was used for determination of phenols in river water ... 

Phthalates can be identified by adding the acidified test solutions to resorcinol or phenol, followed by heating in an oil bath at the boil for a few minutes. After cooling and diluting, 1 N sodium hydroxide solution is added and stirred. If phthalates are present, the resorcinol test shows a pronounced green fluorescence. In the phenol test, a red colouration caused by phenolphthalein is produced. Both sebacates and ricineolates also give a faint positive fluorescence in the resorcinol test, but do not produce colour in the phenol test. 

A new type of situation arose with the use of carbon for potable water supplies. It was soon recognized that decolorizing properties as measured by the M-RE would be needlessly costly because they have no direct value for removing tastes and odors from water supplies. A search for a test that would reveal the power of a carbon for removing taste and odor resulted in the phenol test. This made it practicable to produce carbons that not only were more effective for control of taste and odor but also could be manufactured at a much lower cost. All of this contributed much to great subsequent expansion in the use of carbon for potable water supplies. 

The phenol test also gives a good index of the relative odor-removal power of carbons, but the test is less convenient to conduct. 

The /-RE should be included because it gives a different response from the M-RE on several batches. However, there is no need to include the phenol test because this almost duplicates the figures furnished by the /-RE. As the Ponceau test shows departures from... 

Most other inhibitors, as long as they contain the basic 2,6-di-fer -butylphenol structure, can be included in this correlation. The circles plotted in Figure 6 represent data for most of the phenols tested besides BHT and 2-ter -butyl-4-methylphenol. The lower line appears to be a reasonable correlation for both the monofunctional phenols as well as commercial stabilizers when the actual molarity of the phenolic groups is plotted. The full utilization of all of the phenolic groups on the polyfunctional inhibitors is somewhat surprising, but is consistent with other aspects of this investigation as described later. 

The aniioxidative potency of a compound is related to its structure, in particular to electron delocalization of the aromatic nucleus and is also influenced by the number of hydroxyl groups (/3). In this way, the higher antioxidative activity of rosmarinic acid with respect to that of the other phenolics tested could be related with the presence of two catechol groups on its molecule. However, since the ICj value for rosmarinic acid is less than half of that for caffeic acid (Table II), other mechanisms for superoxide anion deactivation may be involved. 

Phenol test 9. KHSO -H2SO -phenol test (Defacqz reaction) a little of the solid (or... 

The impact of different surfactants (SDS, DOSS, CTAB and hexadimethrine bromide, bile salts °), nonionic and mixed micelles, and additives (neutral and anionic CDs," " tetraalkylammonium salts, organic solvents in EKC separations has been demonstrated with phenol test mixtures. In addition, phenols have been chosen to introduce the applicability of more exotic EKC secondary phases such as SDS modified by bovine serum albumin, water-soluble calixarene, " starburstdendrimers, " " cationic replaceable polymeric phases, ionenes, amphiphilic block copolymers,polyelectrolye complexes,and liposome-coated capillaries. The separation of phenols of environmental interest as well as the sources and transformations of chlorophenols in the natural environment have been revised. Examples of the investigation of phenols by EKC methodologies in aquatic systems, soil," " and gas phase are compiled in Table 31.3. Figure 31.3 illustrates the electromigration separation of phenols by both CZE and EKC modes. 

Emergency examinations, (i) In addition to the surveillance required by (i)(1)(i), if an empioyee is exposed to benzene in an emergency situation, the employer shall have the employee provide a urine sample at the end of the employee s shift and have a urinary phenol test performed on the sample within 72 hours. The urine specific gravity shall be corrected to 1.024. 

WEL 8-hour TWA Ippm. This excellent solvent is seldom used today because of its toxic effects. It may be inhaled or absorbed via the skin and is readily absorbed by fatty tissues. A large proportion of benzene which enters the body is stored in the bone marrow which may be damaged, causing anaemia or more rarely leukaemia. Benzene is altei chemically in the body and then excreted in the mine. For exposures about the WEL, blood benzene is a useful measmement. For lower exposures, breath benzene is suitable. Urinary excretion as a phenol test is no longer recommended. 

Along these lines, We have explored the possibility that red wine and red wine phenolics (e.g., anthocyanin fraction) promoted the formation of NO from nitrite in a pH-dependent and concentration-dependent way. This has been substantiated in vivo in healthy volunteers by measuring NO in the air expelled from the stomach, following consumption of wine and nitrate, as measured by chemiluminescence (Gago et al, 2007). Structure-activity studies revealed that the formation of NO from nitrite directly correlates with the reduction potential of the several phenols tested, including dimers B2, B5, B8, catechin, epicatechin, and quercetin, among others (results not published). EPR studies showed that, mechanistically, the reaction involves the one-electron reduction of nitrite to NO by the polyphenols and the concomitant formation of phenol-derived phenoxyl radicals (Gago et al, 2007) (Fig. 11.1). 

Gibbs, H. D. "Phenol Tests I A Classification of the Tests and a Review of the Literature." Chemical Reviews, 3 1926,291-319. 

Fig. 16. Proof of peak homogeneity with the help of an orthogonal" column. Pyridine/benzylamine/phenol test on three phase types in acidic methanol phosphate buffer. For comments, see text.

This study was undertaken to test the ability of our previous molecular connectivity models to accurately predict the soil sorption coefficients, bioconcentration factors, and acute toxicities in fish of polycyclic aromatic hydrocarbons (PAHs), alkylbenzenes, alkenylbenzenes, chlorobenzenes, polychlorinated biphenyls, chlorinated alkanes and alkenes, heterocyclic arid substituted PAHs, and halogenated phenols. Tests performed on large groups of such compounds clearly demonstrate that these simple nonempirical models accurately predict the soil sorption coefficients, bioconcentration factors, and acute toxicities in fish of the above compounds. Moreover, they outperform traditional empirical models based on 1-octanol/ water partition coefficients or water solubilities in accuracy, speed, and range of applicability. These results show that the molecular connectivity models are a very accurate predictive tool for the soil sorption coefficients, bioconcentration factors, and acute toxicities in fish of a wide range of organic chemicals and that it can be confidently used to rank potentially hazardous chemicals and thus to create a priority testing list. ... 

The Ferric Chloride Phenol Test. —Many phenols give typical blue, green, purple, or red colors when a drop of ferric chloride is added to a dilute aqueous solution of the unknown. A number of phenols which do not give this test readily are found to respond when tested in alcoholic solution. Among the carboxy derivatives of phenol, those having the carboxyl group ortho to the phenolic hydroxyl, as in salicylic acid, respond with a typical deep purple color, but many compounds with the carboxyl group in the meta or para position fail to respond to the test. 

Prepare the phenol test dilutions from a standardised stock 5 per cent solution in distilled water of pure phenol (crystallising-point not less than 40-5°). Prepare the disinfectant test dilutions (usually in a series differing by 10 per cent or thereabouts) from an initial 1 or 2 per cent master dilution in distilled water. In making the master dilution always measure the disinfectant by pipette into the required volume of water and then mix thoroughly any other procedure might affect the quality of the emulsion formed and hence its disinfecting power. 

A summary of the strong acid/phenolic tests for carbohydrates is given in Table 3.2. 

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