Oxidation of phenolic acid surrogates and target analytes during acid extraction of natural water samples for analysis by GC/MS using EPA method 625

Chen, Paul H.; VanAusdale, William A.; Roberts, Dwight F.

doi:10.1021/es00015a025

Cited by 14 publications

(6 citation statements)

References 9 publications

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“…Chen et al (1991) explained a similar observation in terms of the formation of oxidation products that were either insoluble in acidic media, or undetectable by the method used for analysis (GC/MS).…”

Section: Discussionmentioning

confidence: 71%

“…No change in phenol concentration was observed for samples at pH > 6 over a period of days. Chen et al (1991) investigated low phenol recoveries by EPA Method 625 in water samples containing manganese, and found phenol was oxidized to p-benzoquinone in acidified water samples containing manganese oxides. No detailed systematic study of conditions under which phenol oxidation by manganese oxides occurs has been conducted.…”

Section: Introductionmentioning

confidence: 99%

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Oxidation of Phenol in Acidic Aqueous Suspensions of Manganese Oxides

Ukrainczyk

1992

Clays and clay miner.

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Abstract--Phenol (benzenol) oxidation by three synthetic manganese oxides (buserite, manganite, and feitknechtite) has been studied in aerated, aqueous, acidified suspensions. The rate of reaction was pH dependent. Oxidation was greatly enhanced below pH 4, when diphenoquinone and p-benzoquinone were identified as the first products. Initial reaction rate was correlated with standard reduction potential (E ~ of the oxides following the order: feitknechtite > manganite > buserite. A more gradual process of phenol oxidation after the initial reaction was influenced by electrochemical properties of the solution. High soluble manganese activity and increase in pH adversely affected reaction rates. Thus, the reactivity of the oxides was related to their stability and possibly the ability to readsorb Mn(II), following the order: buserite > manganite > feitknechtite. The results indicate that thermodynamic and electrochemical data for oxides and phenols are useful in predicting under which conditions phenols can be oxidized by a given system.

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Section: Discussionmentioning

confidence: 71%

Section: Introductionmentioning

confidence: 99%

Oxidation of Phenol in Acidic Aqueous Suspensions of Manganese Oxides

Ukrainczyk

1992

Clays and clay miner.

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“…The oxidation and coupling of phenols catalyzed by manganese oxides may also play an important role in the analysis of water samples for phenolic pollutants. For example, extraction of natural water samples containing manganese by U.S. Environmental Protection Agency (EPA) Method 625 has been shown to give very low recoveries of phenols due to oxidation of phenols by manganese oxide [4].…”

Section: Discussionmentioning

confidence: 99%

Oxidation and dechlorination of chlorophenols in dilute aqueous suspensions of manganese oxides: Reaction products

Ukrainczyk

McBride

1993

Enviro Toxic and Chemistry

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Some monomeric and dimeric oxidation products of para‐ and/or ortho‐chlorinated phenols in dilute (1 mmol/L phenol), acidified, aqueous suspensions of manganese oxide (Na‐buserite) were identified by MS, Fourier‐transform IR spectroscopy and UV/visible spectroscopy. The para‐chlorinated phenols (4‐chlorophenol, 2,4‐dichlorophenol, 2,4,6‐trichlorophenol, 4‐chloro‐2‐methylphenol) gave corresponding p‐benzoquinones (benzoquinone, 2‐chlorobenzoquinone, 2,6‐dichlorobenzoquinone, 2‐methylbenzoquinone) as the detectable water‐soluble oxidation products. Dimeric products were present in the extracts obtained by washing the oxide with methylene chloride. Michael addition of phenolate to quinone seems to be the predominant mode of coupling. Chlorinated phenols without chlorine in the para‐position (2‐chlorophenol, 2,6‐dichlorophenol) were more difficult to oxidize and afforded diphenoquinones as the only detectable water‐soluble products. For all studied phenols, with the exception of 2,4,6‐trichlorophenol, the amount of water‐soluble products accounts only for a small fraction of oxidized phenol. The quinone and diphenoquinone products readily couple with phenols into humuslike materials.

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“…Oxidation of a related chemical, 2,4,6-tribromophenol, in water samples containing manganese oxide has been shown to give small amounts of a similar product, 2,6-dibromohydroquinone [12]. The third peak corresponds to a compound with an isotopic pattern ( Fig.…”

Section: Oxidation Productsmentioning

confidence: 98%

The Oxidative Dechlorination Reaction of 2,4,6-Trichlorophenol in Dilute Aqueous Suspensions of Manganese Oxides

Ukrainczyk¹,

McBride²

1993

Environ Toxicol Chem

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Oxidation of 2,4,6-trichloropheno1 (TCP) by layered manganese oxides (Na and Co-buserite) in dilute acidified aqueous suspension gives 2,6-dichloro-p-benzoquinone as a major product. This compound is likely to further polymerize and become incorporated into humuslike materials. The oxidation rate was higher at lower pH and higher on Na-buserite compared to Co-buserite. TCP reacted at a faster rate than unsubstituted phenol at pH 3 and 5.5, which is explained by (a) the lower half-wave potential of TCP compared to phenol; (b) a stronger bond dipole associated with the electronegative halogen, favoring an addition step in nucleophilic substitution; and (c) easier depronation of TCP at the manganese oxide-water interface due to its lower pK,. IR spectroscopy shows that TCP adsorbs in deprotonated form on the surface of manganese oxide, and it cannot be washed from the surface by water. Nucleophilic attack by addition-elimination is suggested as a mechanism of TCP dechlorination and oxidation.

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Oxidation of phenolic acid surrogates and target analytes during acid extraction of natural water samples for analysis by GC/MS using EPA method 625

Cited by 14 publications

References 9 publications

Oxidation of Phenol in Acidic Aqueous Suspensions of Manganese Oxides

Oxidation of Phenol in Acidic Aqueous Suspensions of Manganese Oxides

Oxidation and dechlorination of chlorophenols in dilute aqueous suspensions of manganese oxides: Reaction products

The Oxidative Dechlorination Reaction of 2,4,6-Trichlorophenol in Dilute Aqueous Suspensions of Manganese Oxides

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