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A method for analyzing phenolic acids and polyphenols by means of resonant two-photon ionization (R2PI) mass spectrometry coupled with laser desorption and supersonic jet cooling is described. The R2PI spectra of gallic acid, 3-O-methylgallic acid, protocatechuic acid, syringic acid, vanillic acid, and trans-resveratrol are vibronically resolved and distinct to allow for unambiguous identification. For vanillic acid, its R2PI spectrum can be separated into contributions of two rotational isomers based on UV-UV and IR-UV double-resonance spectroscopy. Since R2PI spectra display sharp and well-resolved peaks, the laser wavelength can be tuned for selective ionization of targeted molecules. The mass spectrum recorded under jet-cooled conditions and at the resonant wavelength displays only the molecular ion peak with no fragmentation or background peaks. Picogram sensitivity and linear response over a nanogram range allows trace quantitative measurements of target molecules in complex matrixes. These techniques were applied to detect syringic acid in a model archaeological wine vessel.

The microwave spectral analysis of 4-pentyn-1-ol, HO[(C[H.sub.2]).sub.3]C=CH, and one deuterated species (DO(C[H.sub.2]).sub.3]C=CH) is presented. The results showed a total of 14 spectroscopically different all-staggered rotameric forms with small energy differences.

The analysis of chlorinated phenols (2-chlorophenol, 3-chlorophenol, 4-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, pentachlorophenol) in river water was accomplished using off-line solid-phase extraction (SPE) and capillary electrophoresis coupled with electrochemical detection. A key to the sensitive, reproducible, and stable detection of these pollutants was the use of a boron-doped diamond microelectrode in the amperometric detection mode. An off-line SPE procedure was utilized to extract and preconcentrate the pollutants prior to separation and detection, with ENVI-Chrom P, a highly cross-linked styrene-divinylbenzene copolymer, being employed as the sorbent. Pollutant recoveries in the 95-100% range with relative standard deviations of 1-4% were achieved. The diamond microelectrode provided a low and stable background current with low peak-to-peak noise. The oxidative detection of the pollutants was accomplished at +1.05 V vs [A.sub.g]/[A.sub.g]Cl without the need for electrode pretreatment. The method was evaluated in terms of the linear dynamic range, sensitivity, limit of quantitation, response precision, and response stability. A reproducible electrode response was observed during multiple injections of the chlorinated phenol solutions with a relative standard deviation of [less than or equal to] 5.4%. Good electrode response stability was observed over many days of continuous use with no significant electrode deactivation or fouling. The separation efficiencies for all six pollutants were greater than 170 000 plates/m. The minimum concentration detectable for all six ranged from 0.02 to 0.2 ppb (S/N [greater than or equal to] 3) using a 250:1 preconcentration factor.

A new organic-free mode of headspace liquid-phase microextraction termed headspace water-based liquid-phase microextraction has been developed. Five phenols were used as model compounds in the development and evaluation of the procedure. Parameters affecting the extraction efficiency were investigated. Under optimal extraction conditions, very high enrichment factors were achieved. Since only water (with sodium hydroxide to adjust the pH) and a conventional microsyringe were used, this new technique is affordable, efficient, and convenient for extraction of volatile and semivolatile ionizable compounds. In addition, in combination with capillary electrophoresis, the entire analytical process is totally organic solvent-free and is thus environmentally friendly.

A new dynamic liquid--liquid--liquid microextraction procedure, with the automated movement of acceptor phase (LLLME/AMAP) to facilitate mass transfer, was developed in this study. Four compounds, 3-nitrophenol, 4-nitrophenol, 3,4-dinitrophenol, and 2,4-dichlorophenol, were used as model compounds to be preconcentrated from water samples. The extraction involved filling a 2-cm length of hollow fiber with 4 [micro]L of acceptor solution using a conventional microsyringe, followed by impregnation of the pores of the fiber wall with 1-octanol. The fiber was then immersed in 4 mL of aqueous sample solution. The analytes in the sample solution were extracted into the organic solvent and then back-extracted into the acceptor solution. During extraction, the acceptor phase was repeatedly moved in and out of the hollow fiber channel and the syringe controlled by a syringe pump. Separation and quantitative analyses were then performed by using high-performance liquid chromatography. The results indicated that up to 400-fold enrichment of the analytes could be obtained under the optimized conditions. The enrichment factors were two times those of static liquid--liquid--liquid microextraction. Good repeatabilities (RSD values below 9.30%) were obtained. The calibration linear range was from 10 to 1000 ng/mL with the square of the correlation coefficient ([r.sup.2]) > 0.9916. Detection limits were in the range of 0.45-0.98 ng/mL. In addition, as compared with the previously reported dynamic three-phase microextraction in which there was no relative movement between the acceptor and the organic phase (which is not conducive to effective mass transfer), this new method shows much higher extraction efficiency. All these results suggest that this new dynamic LLLME/AMAP technique could be a better alternative to the previous LLLME for the extraction of analytes from aqueous samples.

Amperometric O2 and H2O2 sensors are used to kinetically examine catalase activity (conversion of H2O2 to (1/2)O2 and H2O) and peroxygenase activity (H2O(sub 2-) dependent oxygenation of substrates) of mushroom tyrosinase. It is found that the catalase activity of mushroom tyrosinase is three-order of magnitude greater than that of mollusk hemocyanin.

A theoretical analysis concerning the study of the influence of the substituent X on the acidity of a set of parasubstituted phenols X-C6H4OH is presented. Linear correlation analyses between calculated Gibbs free energy changes on dissociation of parasubstitued phenolsin the gas phase, the hydrogen atom charge of X-C6H4OH (q(sub H),and the electronegativity of the fragment X-C6H4(sub ChiXC6H4O) show that acidity is related to qH and ChiXC6H4O.

A strategy to achieve ortho substitution of phenols initiated by an ortho-palladation to create coumarins is examined. Numerous important naturally occurring coumarins are synthesized, including fraxinol methyl ether, ayapin, herniarin, xanthoxyletin and alloxanthoxyletin.

A continuous flow system is used to measure the ability of potassium persulfate to oxidize 4-chloro-3-methylphenol. Graphs show the conversion of 4-chloro-3-methylphenol in relation to temperature, and the rates of resulting corrosion and sulfate effluent production.

Two soil samples taken from Riley County, Kansas are contaminated with phenol, 2,4-dichlorophenol (DCP), 1-napthol, and o-cresol; and treated with a horseradish peroxidase (HRP) with H(sub 2)O(sub 2). Phenol sorption and desorption rates are measured and graphed and a discussion of the peroxidase immobilization of the contaminants follows the experimental section.

Research into the geometries and singlet-triplet splittings for the 10 geometrical isomers of didehydrophenol is presented. It is possible to accurately estimate the singlet-triplet splittings by correlation with proton hyperfine coupling constants in antecedent monoradicals.

Ozone gas is injected into an agitated vessel containing aqueous dichlorophenols. The study indicates that ozonation can effectively remove 2,4- and 2,6- dichlorophenols. Accompanying charts and graphs provide additional statistical data.

Analysis indicates that pervaporation-flow injection offers several advantages over equilibrium static techniques when determining Henry's law constant for phenols. Experimental procedures and results are discussed in detail.

Photocatalysis studies in the conversion of anisole to phenol were undertaken.

Indirect synthesis of keto endoperoxide from cyclohexa-1,2-diene involves a base treatment to generate dioxygen and phenol. Another effective methodology is by introducing three oxygen functionalities to 1,4-cyclohexadiene.

A molecularly imprinted polymer (MIP) able to bind 4-nitrophenol (4-NP) was prepared using noncovalent molecular imprinting methods and evaluated as a selective sorbent in molecularly imprinted solid-phase extraction (MISPE) on-line coupled to a reversed-phase HPLC. It has been shown that the conditions chosen for washing the MIP and for eluting the analyte in the MISPE process are extremely important for ensuring good selectivity and recovery. River water samples, spiked with the 11 Environmental Protection Agency phenolic compounds at microgram per liter levels, were preconcentrated on-line using this MIP, and 4-NP was selectively extracted. The humic acid interference was simultaneously reduced considerably. The MIP was also compared with a commercially available highly cross-linked polymer (LiChrolut EN) and the former yielded cleaner extracts.

University researchers investigated the sorption of ionizable organic solutes such as benzene, phenol and aniline on surfactant-modified zeolite.

Researchers measured the concentrations of polychlorinated dibenzofurans, dibenzo-p-dioxins, naphthalenes, polycyclic aromatic hydrocarbons and nonylphenol from a sediment core collected from the Tokyo Bay in Japan.

A study of the effects of oxidizing phenol in supercritical water with TiO2 as the catalyst.

An efficient oxygenation was achieved in aprotic solvents by doping them with small amounts (0.1% or less) of carboxylic acids and phenols. A kinetic analysis showed that the effect is due to the interaction of the protic additives with the first formed intermediate, the persulfoxide, in competition with cleavage to the components.

Research points out that the oxidative cyclization of phenolic omega-arylalkanoic carboxamides to spirolactams can be accomplished using iodobenzene diacetate via oxazoline intermediates. Results suggest that these transformations of the organic hypervalent iodine chemistry are useful in the syntheses of azaspirocyclic products.

A novel method for regioselective oxidation of phenols and anisoles to produce CF(sub)3-containing spiro 2-hydroxydienones using dioxiranes. Data indicate that the oxidation involves regioselective pi-bond epoxidation and epoxide rearrangement with hemiketal formation.

Research into the role of crystal phase in photocatalytic oxidation of phenol in water is presented. The Degussa P25 and silica-titania TiO2-based photocatalysts were investigated in detail.

Research has been conducted on the serotonin photolable o-nitrobenzyl derivatives. The synthesis of these derivatives has been carried out.

Research has been conducted on the lipopolysaccharides (LPS). The isolation of the LPS from Danish Helicobacter pylori strains by hot phenol-water extraction is described.

Density functional calculations of the reaction of the cyclic tetramer of bisphenol A polycarbonate with the molecules lithium phenoxide, phenol and sodium phenoxide are presented. The balance between changes in entropy and energy is considered.

The phenolic hydrogen atoms of o-methoxyphenols are shown to be abstracted readily by radicals.

Research is presented describing the use of static bomb combustion calorimetry to measure the standard molar enthalpies of formation for gas phase 2-, 3-, and 4-phenylpyridine, obtained from the standard molar enthalpies of combustion in oxygen at 298.15 K.

High-level ab initio calculations have been used to investigate the torsional potentials of methoxy and hydroxyl groups of omichron-hydroxyanisole. It was established that the intramolecular bond significantly stabilizes the energy minimum structure.

Laser flash photolysis has been used to assess absolute biomolecular rate constants for the quenching of the aromatic ketones 3'-methoxyacetophenone, benzophenone and 2-acetonaphthone by nine substituted phenols.

Researchers from the University of Toronto, Ontario, Canada investigated the production of trifluoracetic acid when the lampricide 3-trifluoromethyl-4-nitrophenol undergo photolytic degradation when added to the Great Lakes (Superior, Michigan, Huron and Ontario).

A density functional study at the BLYP/6-3G(d,p) level on phenol and its four derivatives creating hydrogen-bonded complexes with ammonia subunit is presented. All the phenol derivatives investigated in this research form quite strong hydrogen-bonded complexes with ammonia subunit.

It has been possible to analyze the reaction pathways and the energetics for the direct hydroxylation of methane and of benzene that arise on the surface of Fe-ZSM-5 zeolite. The 'two-step concerted mechanism' should be widely used in analyzing how hydrocarbon hydroxylations are catalyzed by transition-metal oxides.

Laster flash photolysis methods were used to study the photochemistry of a range of alkoxyacetophenone derivatives having remote phenolic groups.

The spectroscopic properties and structure of phenol blue, [N-(4-dimethylaminophenyl)-1,4-benzoquinoneimine, are assessed and theoretical calculations are performed on the indoaniline.

The S2 (1A1) state of phenol was studied using two-photon resonance-enhanced photoionization together with photoelectron spectroscopy.

Research is presented describing the characterization and generation of different methyl- and methoxy-substituted phenol radical cations using laser flash photolysis.

Research has been conducted on the O,N-chelated vanadium(IV) oxo bis(phenolate) complexes. The preparation of these complexes from [VOCl (sub)2 -(THF) (sub)2] and ortho-amino-functionalized phenols is described.

Research has been conducted on the phenol-based macrocyclic ligands. Results indicate that they have a salen-like metal-binding site.

Metallic palladium was observed to catalyze the deep oxidation of a broad range of functional organics by dioxygen at 80-90 degrees C in water and in the presence of carbon monoxide or dihydrogen. Several classes or organic compounds were studied: benzene, pheno and substituted phenols, nitro and halo organics, organophosphorus, and organosulfur compounds. For all cases, deep oxidation to CO, CO2 and water occurred in high yields, resulting in up to several hundred turnovers over a 24 hr period.

A cyclic voltammetry study was conducted to determine the oxidation peak potentials (Ep) of 31 phenolate, chlorophenolate and other para-substituted phenolate ions in aqueous solution at pH 12 as a function of scan rate. The dependence of one-electron reduction potentials of the phenoxyl radical/phenolate ion couples on pH was established after such potentials were evaluated from Ep and the rate constants for dimerization of the phenoxyl radicals. The pKa values of the phenols and the protonated phenoxyl radical cations were also investigated.

Research was conducted to determine a high-level expression in Escherichia coli of a fully active recombinant form of a catalase-peroxidase (KatG) from the cyanobacterium Synechocystic PCC 6803. Its identity with the wild-type protein was revealed by physical and kinetic characterization. The spectral characteristics of KatG compounds I and II and the rates of reaction of 11 aromatic donor molecules with Synechocystis KatG compound I, determined by sequential-mixing stopped-flow spectroscopy, are described.

N-(alpha-amino(hetero)arylmethyl)benzotriazoles derived from several kinds of (hetero)amino aldehydes were reacted with sodium phenolates to produce amino(hetero)arylmethylated phenols in high yields. This represents a convenient technique for the preparation of aminoalkylated phenols via aminoalkylbenzotriazoles. Compared to the previous techniques, this route employs readily available starting materials and offers high yields for various substituted phenols and (hetero)aromatic aldehydes.

Research was conducted to examine the jet-cooled 1:1 complex of phenol and ethanol using ab initio calculations at the Hartree-Fock 6-31G(d,p) level and various laser spectroscopic methods. It was shown that the electronic S1

Optically active 2-hydroxymandelic esters and acids were synthesized by direct hydroxyalkylation of phenols with very high yields and diastereoselectivities. The reaction occurs with complete ortho regioselectivity with mono attack on the phenol ring, and no diphenyl methane derivatives are produced. The hydrolysis and reduction of the products permit the isolation of enantiomerically pure 2-hydroxymandelic acids and 2-hydroxyphenyldiols, respectively.

The impact of numerous media on the capability of several categories of phenolic antioxidants were calculated using stopped flow methods in hexane, 1-propanol, tert-butyl alcohol and acetone. Reductions in the transfer from hexane to the hydrogen bond accepting solvents were credited to hydrogen bonding from the phenolic group. The catechol DTBC indicated a substantial decrease in activity in hydrogen bond accepting solvents. The antioxidant properties of alpha-tocopherol, 2,2,5,7,8-pentamethyl-6-hydroxychroman, catechol and 3,5-di-tert-butylcatechol were determined using the oxygen uptake method.

A study was conducted to analyze the effects of surface chemistry on the adsorption of water on activated carbons. The DMS Titrino 716 automatic titrator was utilized to carry out potentiometric titration measurements. The Nicolet Impact 410 spectrometer was then used to obtain infrared spectra. Experimental results indicated that washing with methanol modified the surface chemistry of carbons and promoted the creation of phenols and novel hydrolyzed esters.

A study was conducted to analyze the methoxymethylation of phenols, alcohols and avermectin aglycones. Methoxymethyl moiety-2-pyridylsulfide (MOM-ON) was utilized to carry out the analysis. The Zorbx SB phenyl column was utilized to perform high performance liquid chromatography. Experimental results indicated that effectiveness of MOM-ON as a methoxymethylating reagent of alcohols and phenols.

A series of phenolic compounds were examined with respect to their lipophilicity in the 1,2-dichloroethane (1,2-DCE)/water system. Cyclic voltammetry at the immiscible electrolyte solutions was then used to investigate the tranfer characteristics of the charged species. Their partition coefficient was deduced from their formal potential and the log P (sub DCE) values were measured by a two-phase pH metric-method for the neutral species.

The kinetics of hydrogen atom transfer from substituted phenols to primary alkyl radicals were studied. It was established that hydrogen atom shift from a phenolic antioxidant resulted in a hydroperoxide and an aryloxyl radical. It was observed that the rate constants for the hydrogen atom abstraction from 18 phenols were greater in phenols having electron-donating para substituents and lesser in phenols substituted with electron-withdrawing groups.