Determination of phenol

Xylene is the most important aromatic solvent used in the paint, varnish and adhesives industries, and is also a starting material in the production of plastics. It enters the human organism by the same routes as benzene and toluene, and the clinical picture is similar to that for toluene. 

The following limit values apply to xylene (all isomers)  

Injection volume and syringe temperature Injector temperature Temperature program 

Phenol is the main metabolite of benzene. It occurs mainly in foamed organic products, plastics, adhesives, tar and tarred roofing felt. Phenol is also a physiological metabolic product of intestinal bacteria. Entry into the human organism is analogous to that of benzene. The clinical picture corresponds to that of the BTX aromatics. 

CH 1 PKNO 8 14 ZEIT 1.902 5.545 PLAECHE 3293 8395 HOEHE 1266 1671 MK IDN0 C0NC R 1 NAME PHENOL 

Discussion. A number of phenols can be substituted rapidly and quantitatively with bromine produced from bromate and bromide23 in acid solution (Section 10.131). The determination involves treating phenol (Note 1) with an 

Procedure. Prepare an approx. 0.02M standard solution of potassium bromate by weighing accurately about 1.65 g of the analytical grade reagent, dissolving it in water and making it up to 500 mL in a graduated flask (Note 2). 

Calculate the amount of excess bromate from the amount of thiosulphate needed for the back-titration of the free iodine, and hence the quantity of bromate which reacted with the phenol. 

(1) Other phenols which undergo this type of reaction include 4-chlorophenol, m-cresol (3-methylphenol) and 2-naphthol. 

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HPLC DETERMINATION OF PHENOLS WITH PHOTOMETRIC AND AMPEROMETRIC DETECTORS... 

For selective estimation of phenols pollution of environment such chromatographic methods as gas chromatography with flame-ionization detector (ISO method 8165) and high performance liquid chromatography with UV-detector (EPA method 625) is recommended. For determination of phenol, cresols, chlorophenols in environmental samples application of HPLC with amperometric detector is perspective. Phenols and chlorophenols can be easy oxidized and determined with high sensitivity on carbon-glass electrode. 

The comparison of analytical characteristics HPLC methods of determination of phenols with application amperometric and photometric detectors was caiiy out in this work. Experiment was executed with use liquid chromatograph Zvet-Yauza and 100 mm-3mm 150mm-3mm column with Silasorb C18 (5 10 p.m). With amperometric detector phenols were detected in oxidizing regime on glass-cai bon electrodes. With photometric detector phenols were detected at 254 nm. 

ANALYTICAL APPLICATION OF SILICAS WITH COVALENT AND ION-EXCHANGE BONDING OF IMMOBILIZED ORGANIC COMPOUNDS FOR SELECTIVE PRE-CONCENTRATION AND DETERMINATION OF PHENOLIC POLLUTANTS... 

E. Pocurull, R. M. Marce and E. Bonttll, Determination of phenolic compounds in natural waters by liquid cliromatography with ulrtaviolet and elecrtochemical detection after on-line trace enrichment , / Chromatogr. 738 1-9(1996). 

E. R. Brouwer and U. A. Th Brinkman, Determination of phenolic compounds in surface water using on-line liquid chr omatographic precolumn-based column-switching tecniques , J. Chromatogr. 678 223-231 (1994). 

The usual method for the determination of phenols is based on the solubility of these compounds in solutions of caustic alkali. Such absorption methods are not strictly accurate, since a small portion of constituents other than phenols are dissolved by the alkali. So long, however, as the conditions are kept constant, useful comparative results are obtained. The process is best carried out as follows —... 

Schryver has recommended the use of sodamide for the determination of phenols the hydrogen of the phenolic hydroxyl replaces the sodium with the formation of an equivalent quantity of ammonia,... 

Hong, V. and Wrolstad, R.E., Use of HPLC separation/photodiode array detection for characterization of anthocyanins, J. Agric. Food Chem., 38, 708, 1990. Osmianski, J. and Lee, C.Y., Isolation and HPLC determination of phenolic compounds in red grapes. Am. J. Enol. Vitic., 41, 204, 1990. 

Hvattum, E., Determination of phenolic compounds in rose hip (Rosa canina) using liquid chromatography coupled to electrospray ionisation tandem mass spectrometry and diode-array detection, Rapid Commun. Mass Spectrom., 16, 655, 2002. 

Alvarez-Suarez, J. M., TuUpani, S., Romandini, S., Vidal, A., and Battino, M. (2009). Methodological aspects about determination of phenolic compounds and in vitro evaluation of antioxidant capacity in the honey A review. Curr. Ami. Client. 5, 293-302. 

Andrade, P., Ferreres, F., Gil, M. I., and Tomas-Barberfe, F. A. (1997). Determination of phenolic compounds in honeys with different floral origin by capillary zone electrophoresis. Food Chem. 60, 79-84. 

Jorg, E. and Sontag, G. (1992). Determination of phenolic acids in honey by HPLC using coulometric dual electrode detection. Dtsch. Lebensm. Rundsh. 88,179-183. 

Sontag, G., Friedrich, O., Kainz, G., and Jorg, E. (1989). Determination of phenolic compounds by HPLC with electrochemical detection. Proc. EUR 5th Food Chem. Conference, Agric. Food Chem. Consum. 2, 703-707. 

Analysts in industry prefer in many cases to maintain consistent methods for their analyses. Recommended ASTM analytical procedures are quite well developed in the rubber and polymer industry. As an example, we mention the standard test method for determination of phenolic antioxidants and erucamide slip additives in LDPE using liquid chromatography [76]. However, the current industry standard test methods (ASTM, AOAC, IUPAC, etc.) use a large number of solvents in vast... 

ASTM D 1996-97, Standard Test Method for Determination of Phenolic Antioxidants and Erucamide Slip Additives in Low Density Polyethylene Using Liquid Chromatography (LC), Annual Book of ASTM Standards, ASTM, West Conshohocken, PA (1997), Vol. 08.01. 

SPE-NACE-UV has been employed for the determination of phenols (in environmental samples as byproducts in the production of plastics and dyes and in... 

Crompton [21] has reviewed the use of electrochemical methods in the determination of phenolic and amine antioxidants, organic peroxides, organotin heat stabilisers, metallic stearates and some inorganic anions (such as bromide, iodide and thiocyanate) in the 1950s/1960s (Table 8.75). The electrochemical detector is generally operated in tandem with a universal, nonselective detector, so that a more general sample analysis can be obtained than is possible with the electrochemical detector alone. 

Hi) The determination of phenols as contaminants in a sample of river water. 

A wide variety of methodologies have been employed for the analysis of antioxidants in polymers and some standard methods are available. For high-density polyethylene ASTM method D5524 (ASTM International) — Determination of phenolic antioxidants in high-density polyethylene, describes a method whereby the sample is ground to a small particle size and then extracted by refluxing with cyclohexane. The cyclohexane extract is then examined by reverse-phase HPLC with UV detection. 

Experiment II. Determination of phenolic acids byHPLC analysis... 

Experiment III. Determination of phenolic acids by HPLC analysis Material required, Procedure, Statistical analysis and Precaution are the same as described in Section 3.3. 

Vanrensen, I. and Veit, M. (1995). Simultaneous determination of phenolics and alkaloids using ion-exchange chromatography for sample preparation. Phytochemical Analysis 6 121-124. 

Harnly JM, Bhagwat S and Lin LZ. 2007. Profiling methods for the determination of phenolic compounds in foods and dietary supplements. Anal Bioanal Chem 389(1 ) 47—61. 

Li P, Wang XQ, Wang HZ and Wu YN. 1993. High performance liquid chromatographic determination of phenolic acids in fruits and vegetables. Biomed Environ Sci 6(4) 389-398. 

Michalkiewicz A, Biesaga M and Pyrzynska K. 2008. Solid-phase extraction procedure for determination of phenolic acids and some flavonols in honey. J Chromatogr A 1187( 1-2) 18-24. 

Stratil P, Klejdus B and Kuban V. 2007. Determination of phenolic compounds and their antioxidant activity in fruits and cereals. Talanta 71 (4) 1741—1751. 

Chun JC, Han KW, Jang BC, Shin HS (1988) Determination of phenolic compounds responsible for allelopathy in upland weeds. Korean J Weed Sci 8 258-264 Chung IM, Miller DA (1995) Effect of alfalfa plant and soil extracts on germination and growth of alfalfa. Agron J 87 762-767... 

Suppliers of visible spectrophotometers are reviewed in Table 1.1. Spectroscopic methods are applicable to the determination of phenols, chlorophenols, amines, mixtures of organics, boron, halogens, total nitrogen and total phosphorus in soils, cationic surfactants, carbohydrates, total nitrogen, phosphorus and sulphur in non-saline sediments, boron, total organic carbon, total sulphur and arsenic in saline sediments, cationic surfactants, adenosine triphosphate and total organic carbon in sludges. 

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