A pyrolysis-derivatisation-gas chromatography technique for the structural elucidation of some synthetic polymers

Challinor, J.M.

doi:10.1016/0165-2370(89)80015-4

Cited by 284 publications

(118 citation statements)

References 13 publications

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“…In agreement with the mechanism proposed by Challinor [7][8][9] and de Leeuw and Bass [10], there are few reasons to assume that a reaction between the macromolecule and TMAH occurs at the pyrolysis temperature which would release the structural units upon pyrolysis. In fact, the reported findings are in general very different to the resultsobtained by direct methylation followed by Py [5].…”

Section: Results Ano Dlscussionsupporting

confidence: 61%

“…In all cases, the products obtained after pyrolysis in the presence of TMAH of the standards were the methyl esters of the original benzenecarboxylic acids. The absence of benzoic acid methyl ester and 1,3-benzofurandione in this case reinforces the high-temperature hydrolysis and alkylation mechanism postuJated by Challinor [1][2][3][4][5][6][7][8][9], and is in agreement with the idea stated by TABLE 3 Main thennal degradative products obtained after pyrolysis of standard compounds in the absencc and in the presenc:e of TMAH de Leeuw and Baas [10] of a T-AC rather than a methylation of the pyrolysis products. The mechanisms suggested for the pyrolytic behaviour of the benzenecarboxylic acids in the absence and in the presence of TMAH are indicated in Figs.…”

Section: Results Ano Dlscussionmentioning

confidence: 82%

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Pyrolysis derivatization of humic substances 1. Pyrolysis of fulvic acids in the presence of tetramethylammonium hydroxide

Martı́n

González-Vila

Rı́o

et al. 1994

Journal of Analytical and Applied Pyrolysis

126

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A BSTRACTPyrograms of Ihree fulvic acids (FAs) or ditferenl origins and Ihe corresponding pyrosrams obtaincd by reactive pyrolysis wilh Iclramclhylammonium hydroxide (TMAH) are compared. Thi! proc.cdure inlroduces bolh slriking qualilalive and quanlilalive changes in lhe pyrolylic pallems of Ihe FAs. which are discussed in lerms of Ihe usefulness of Ihis approach lo slructural sludies. Sorne non·pyrolysis compounds (probably relained in Ihe macromolecular fulvic malrix) seem lo be released when Ihe FAs are pyrolysed in lhe presrnce of TMAH. A se{ of benzenecarboxylic acid slandards was also pyrolysed bolh in lhe abscnce and in Ihe prcscncc: oC TMAH. The resulls oblained suggcsl a lhennally assisled chemolysis ralher Ihan i" s;/u melhylalioD of lhe pyrolysis produclS. Fulvic &cids; humic substances; pyrolysiS; tetramelhylammonium hydroxide. INTRODUCTlONHumic substances (HS) are widely distributed in almost all terrestrial and aquatic environments. Owing to their colloidal properties and high runctionality they play important roles in reactions and processes relaled lO the conservation and production of soil ecosystems. which have been recently reviewed [1,2].The complex. variable composition of lhe fulvic acids (FAs) (lhe alkali and acid-soluble collodial humic fraction) has been investigated by many different methods with divergent results. Overall the struclural ínformation gained by analytical pyrolysis (Py) of FA is unexpectedly much lower than that given by the other humic fractíoDS (humic acids and humíos). Thus, FA givcs low yields of Py compounds. with major components bcíng characteristic of $Oíl polysao:harides, and a small numbcr of aromatic compounds, whereas Py of humíc acids gives much richer pyrograms. This

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Section: Results Ano Dlscussionsupporting

confidence: 61%

Section: Results Ano Dlscussionmentioning

confidence: 82%

Pyrolysis derivatization of humic substances 1. Pyrolysis of fulvic acids in the presence of tetramethylammonium hydroxide

Martı́n

González-Vila

Rı́o

et al. 1994

Journal of Analytical and Applied Pyrolysis

126

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“…A new pyrolytic degradation method involving in situ methylation (TMAH/thermolysis) was carried out following the procedure described by Challinor (1989). Lyophilized dissolved organic samples, -200 ng, were placed in a quartz pyrolysis boat and covered with 4 ~1 of TMAH (tetramethyl ammonium hydroxide, 25% in water).…”

Section: Methodsmentioning

confidence: 99%

Natural photolysis by ultraviolet irradiance of recalcitrant dissolved organic matter to simple substrates for rapidbacterial metabolism

Wetzel

Hatcher

Bianchi

1995

Limnology & Oceanography

489

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Whole leachate and humic and fulvic acid fractions of dissolved organic matter (DOM) released from senescent littoral aquatic plants were exposed to varying spectra of ultraviolet radiation as well as natural UV of sunlight over different periods of time. Examination of the DOM by solid-state 13C nuclear magnetic resonance and pyrolytic gas chromatography-mass spectrometry before and after photolysis revealed only subtle changes to the bulk DOM. However, the DOM exposed to natural UV radiation showed immediate stimulation of and sustained bacterial growth. Chemical analyses by high performance liquid chromatography (HPLC) of the small organic fractions generated by photolysis of humic substances showed marked, pro-' gressively increasing release of numerous small fatty acids, particularly acetic, formic, citric, pyruvic, and levulinic, among others. Use of radiolabeled humic substances demonstrated that these small compounds photolyzed from the humic substances were readily metabolized by the bacteria.Dissolved organic matter (DOM) of the open ocean apparently originates largely from planktonic photosynthesis, and concentrations are usually quite low (0.5-2 mg C liter-l) (Wangersky 1984;Wetzel 1984;Meybeck 1993;Hedges et al. 1993). In inland waters, however, phenolic and other aromatic-based humic compounds, largely of terrestrial and higher aquatic plant origin, form a major component of dissolved organic acids of freshwaters and can constitute some 80% of the total DOM, 30-40% of which is composed of aromatic carbons (Malcolm 1990). Concentrations of 4-8 mg organic acids liter-l are common in surface waters and often exceed 25 mg liter-l in organic-rich waters, such as those of wetlands, floodplains of river ecosystems, and interstitial waters of hydrosoils (Wetzel 1984;Mann and Wetzel 1995).The higher concentrations of DOM in inland surface waters clearly result from high photosynthetic productivity within lake ecosystems, particularly associated with littoral and wetland regions, as well as large loadings of DOM from decomposition of plant materials within the drainage basin (Wetzel 1990(Wetzel , 1992. Similarly, the high photosynthesis and decomposition within the extensive Acknowledgments

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“…On the contrary, pyrolysis of such polyesters in the presence of an organic alkali, such as tetramethylammonium hydroxide (TMAH), resulted in simplified pyrograms which consisted of the sharp peaks of the constituents in polyesters. 5,6 We reported that this method enabled highly sensitive compositional analyses of fully aromatic copolyesters and end group determination of commercially available polycarbonates.7,8 Furthermore, the detailed mechanism of reactive pyrolysis of aromatic polyester in the presence of TMAH solution was also examined by Py-GC/MS using CD3OH as a solvent. 9 In the present work, reactive Py-GC in the presence of organic alkaline reagent was applied to the compositional analysis of cationic PAAm resins.…”

mentioning

confidence: 99%

Compositional Analysis of Cationic Polyacrylamide Resins by Reactive Pyrolysis-Gas Chromatography in the Presence of Organic Alkali

et al. 1996

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Reactive pyrolysis-gas chromatography (Py-GC) in the presence of tetramethylammonium hydroxide (TMAH) was successfully applied to the compositional analysis of cationic polyacrylamide (PAAm) resins, prepared from acrylamide (AAm) and dimethylaminoethylmethacrylate (DM). The reactive pyrolysis of cationic PAAm resulted only in hydrolysis of ester linkages in DM units and did not lead to subsequent methylation of hydrolyzates and cyclization. The intense peak of 2-(dimethylamino)ethanol formed from DM units through the reactive pyrolysis was used as the key peak for the determination of DM content. The content of DM units in the cationic PAAm samples was determined with a precision of about 4% of relative standard deviations.

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A pyrolysis-derivatisation-gas chromatography technique for the structural elucidation of some synthetic polymers

Cited by 284 publications

References 13 publications

Pyrolysis derivatization of humic substances 1. Pyrolysis of fulvic acids in the presence of tetramethylammonium hydroxide

Pyrolysis derivatization of humic substances 1. Pyrolysis of fulvic acids in the presence of tetramethylammonium hydroxide

Natural photolysis by ultraviolet irradiance of recalcitrant dissolved organic matter to simple substrates for rapidbacterial metabolism

Compositional Analysis of Cationic Polyacrylamide Resins by Reactive Pyrolysis-Gas Chromatography in the Presence of Organic Alkali

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