Phenols liquid chromatography

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. 

N. Masque, R. M. Marce and R Bonnll, Comparison of different sorbents for on-line solid-phase exti action of pesticides and phenolic compounds from natural water followed by liquid chromatography , J. Chromatogr. 793 257-263 (1998). 

More recently, the reaction advancement of resole syntheses (pH = 8 and 60°C) was monitored using high-performance liquid chromatography (HPLC), 13C NMR, and chemical assays.55,56 The disappearance of phenol and the appearances of various hydroxymethyl-substituted phenolic monomers and dimers have been measured. By assessing the residual monomer as a function of reaction time, this work also demonstrated the unusually high reactivity of 2,6-dihydroxymethyl-phenol. The rate constants for phenolic monomers toward formaldehyde substitution have been measured (Table 7.6). 

Micellar gradient elution liquid chromatography with electrochemical detection with sodium dodecyl sulfate has been used to separate phenols [186]. 

CALDWELL c R (2001) Oxygen radical absorbance capacity of the phenolic compounds in plant extracts fractionated by high-performance liquid chromatography, ,4Biochem, 293, 232-8. 

Paganga, G. et al.. The polyphenolic content of fruit and vegetables and their antioxidant activities what does a serving constitute Free Radical Res., 30, 153, 1999. Maatta, K.R. et al.. High-performance liquid chromatography (HPLC) analysis of phenolic compounds in berries with diode array and electrospray ionization mass spectrometric (MS) detection Rihes species, J. Agric. Food Chem., 51, 6736, 2003. 

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. 

Kohler M, NV Heeb (2003) Determination of nitrated phenolic compounds in rain by liquid chromatography/ atmospheric pressure chemical ionization mass spectrometry. Anal Chem 75 3115-3121. 

Inoue, K., Murayama, S., Seshimo, F., Takeba, K., Yoshimura, Y., and Nakazawa, H. (2005). Identification of phenolic compound in manuka honey as specific superoxide anion radical scavenger using electron spin resonance (ESR) and liquid chromatography with coulometric array detection. /. Sci. Food Agric. 85, 872-878. 

Jorg, E. and Sontag, G. (1993). Multichannel coulometric detection coupled with liquid chromatography for determination of phenolic esters in honey. /. Chromatogr. A 635, 137-142. 

Long, H., Zhu, Y. X., and Kissinger, P. T. (2003). Liquid chromatography with multi-channel electrochemical detection for the determination of natural phenolic compounds. Chin. J. Anal. Chem. 31, 631-634. 

This technique is based on the same separation mechanisms as found in liquid chromatography (LC). In LC, the solubility and the functional group interaction of sample, sorbent, and solvent are optimized to effect separation. In SPE, these interactions are optimized to effect retention or elution. Polar stationary phases, such as silica gel, Florisil and alumina, retain compounds with polar functional group (e.g., phenols, humic acids, and amines). A nonpolar organic solvent (e.g. hexane, dichloromethane) is used to remove nonpolar inferences where the target analyte is a polar compound. Conversely, the same nonpolar solvent may be used to elute a nonpolar analyte, leaving polar inferences adsorbed on the column. 

Figure 4.29 An example of the use of ternary solvents to control mobile phase strength and selectivity in reversed-phase liquid chromatography. A, methanol-water (50 50) B, tetrahydrofuran-water (32 68) C, methanol-tetrahydrofuran-water (35 10 55). Peak identification 1 - benzyl alcohol 2 phenol 3 3-phenylpropanol 4 2,4-dimethylphenol 5 benzene and 6 -diethylphthalate. (Reproduced with permission from ref. 522. Copyright Elsevier Scientific Publishing Co.)...

Kafil, J. B. and Last, T. A., Liquid chromatography with voltammetric detection for quantitation of phenolic acids,. Chromatogr., 348, 397, 1985. 

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. 

SEC in combination with multidimensional liquid chromatography (LC-LC) may be used to carry out polymer/additive analysis. In this approach, the sample is dissolved before injection into the SEC system for prefractionation of the polymer fractions. High-MW components are separated from the additives. The additive fraction is collected, concentrated by evaporation, and injected to a multidimensional RPLC system consisting of two columns of different selectivity. The first column is used for sample prefractionation and cleanup, after which the additive fraction is transferred to the analytical column for the final separation. The total method (SEC, LC-LC) has been used for the analysis of the main phenolic compounds in complex pyrolysis oils with minimal sample preparation [974]. The identification is reliable because three analytical steps (SEC, RPLC and RPLC) with different selectivities are employed. The complexity of pyrolysis oils makes their analysis a demanding task, and careful sample preparation is typically required. 

Y.Y. Soong and P.J. Barlow, Isolation and structure elucidation of phenolic compounds from longan (Dimocarpus longan Lour.) seed by high performance liquid chromatography electrospray ionization mass spectrometry, J. Chromatogr. A, 1085, 270 277 (2005). 

HPLC) for phenolic acids analysis. When procedure (ii) was applied, the ion-exchange resin was separated from the methanol phase and eluted with three 40 ml aliquots of 80% methanol. The resin bead eluates were evaporated to dryness and subjected to spectrophotometry (Shimadzu UV 160 spectrophotometer) for total phenolics and high-performance liquid chromatography (HPLC) for phenolic acids analysis. 

Over the past two decades, capillary electrophoresis (CE) and related techniques have rapidly developed for the separation of a wide range of analytes, ranging from large protein molecules to small inorganic ions. Gas chromatography has been considered as a powerful tool due to its sensitivity and selectivity, especially when coupled with mass spectrometry. Nevertheless, liquid chromatography is the most used method to separate and analyze phenolic compounds in plant and tissue samples. 

Liquid chromatography, coupled to the different ionization sources, is generally the technique most used to characterize the phenolic profile in fruit and vegetable products. With regard to the source ionization, it seems that ESI is used more frequently than other sources, such as APCI or APPI. Another important aspect of this technique is the ionization of phenolic compounds. Negative ionization seems to be more suitable... 

Aaby K, Hvattum E and Skrede G. 2004. Analysis of flavonoids and other phenolic compounds using high-performance liquid chromatography with coulometric array detection relationship to antioxidant... 

Betes-Saura C, Andres-Lacueva C and Lamuela-Raventos RM. 1996. Phenolics in white free-run juice and wines from Penedes by high-performance liquid chromatography changes during vinification. J Agric Food Chem 44(10) 3040-3046. 

Chen H, Zuo Y and Deng Y. 2001. Separation and determination of flavonoids and other phenolic compounds in cranberry juice by high-performance liquid chromatography. J Chromatogr A 913( 1—2) 387—395. 

Im HW, Suh BS, Lee SU, Kozukue N, Ohnisi-Kameyama M, Levin CE and Friedman M. 2008. Analysis of phenolic compounds by high-performance liquid chromatography and liquid chromatography/mass spectrometry in potato plant flowers, leaves, stems, and tubers and in home-processed potatoes. J Agric Food Chem 56(9) 3341-3349. 

Revilla E and Ryan JM. 2000. Analysis of several phenolic compounds with potential antioxidant properties in grape extracts and wines by high-performance liquid chromatography—photodiode array detection without sample preparation. J Chromatogr 881(1-2) 461 169. 

Reversed phase liquid chromatography-mass spectrometry was applied to extracts of Jamaica Bay (New York) water to determine 1-300 xg/l amounts of nonyl phenol ethoxylates and their metabolites [213]. 

L6pez-Roldan P., de Alda M.J.L., and Barcelo D., 2004. Simultaneous determination of selected endocrine disrupters (pesticides, phenols and phthalates) in water by in-field solid-phase extraction (SPE) using the prototype PROFEXS followed by online SPE (PROSPEKT) and analysis by liquid chromatography-atomspheric pressure chemical ionization-mass spectrometry. Anal Bioanal Chem 378 599. 

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