Comparison of Desorption Mass Spectrometry Techniques for the Characterization of Fulvic Acid

Brown, Teresa L.; Novotny, Frank J.; Rice, James A.

doi:10.1016/b978-1-85573-806-5.50011-3

Cited by 5 publications

(13 citation statements)

References 28 publications

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“…Different from the TOF-SIMS results of Figure 1, the reported positive-ion spectra of SRFA by LD FTMS were significantly broader than the negative-ion spectra and the maximum of the positive-ion spectra was found at higher masses than for negative ions [4]. In contrast to TOF-SIMS and LD FTMS, electrospray FT-ICR MS showed mass distributions of SRFA with maxima around m/z Ϸ 1600 for positive ions [8,9] and m/z Ϸ 730 for negative ions [9].…”

Section: Resultscontrasting

confidence: 88%

“…The TOF-SIMS spectra of SRFA observed in this study are similar to those previously obtained by LD FTMS [4,8] on samples that were also prepared by dissolving fulvic acids in deionised, distilled water but at much higher concentration (ca. 5 mg/mL).…”

Section: Resultssupporting

confidence: 85%

“…The post prominent GA species in the negative spectrum is (GA-H) -, followed by (GA · Na-2H) -. The dimers (GA) 2 are also quite prominent in the positive and negative spectra, and even the multimers (GA) 3 and (GA) 4 can be identified unambiguously.…”

Section: Resultsmentioning

confidence: 98%

“…With reference to their solubility in aqueous solutions they are classified into three fractions, (i) humin, insoluble at all pH-values, (ii) humic acid, soluble at pH > 1, and (iii) fulvic acid, soluble at any pH. In recent years considerable efforts have been made to characterise humic and fulvic acids by mass spectrometry (MS) such as laser-desorption Fouriertransform MS (LD FTMS) [1][2][3][4], fast atom bombardment MS (FAB-MS) [4], matrix-assisted laser desorption/ionisation (MALDI) time-of-flight (TOF) MS [5,6], time-of-flight secondary ion mass spectrometry (TOF-SIMS) [7], and highresolution Fourier-transform ion cyclotron resonance MS (FT-ICR MS), in combination with either laser desorption [8] or electrospray ionisation [8,9]. The results are quite controversial.…”

Section: Introductionmentioning

confidence: 99%

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Characterisation of Fulvic Acids and Glycyrrhizic Acid by Time-of-Flight Secondary Ion Mass Spectrometry

Szymczak¹,

Wolf²,

Wittmaack³

2001

Acta hydrochim. hydrobiol.

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Fulvic acids of different origin, spray deposited on polished silicon after dissolution in high‐purity water without any additives, were analysed by time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS) in combination with oblique 24...36 keV SF5+ ion bombardment. The observed, highly reproducible mass spectra cover more than five orders of magnitude in dynamic range, without background subtraction. Apart from lines due to atomic ions and low‐mass ion fragments, the mass spectra exhibit broad maxima between m/z 200...350, mainly due to a beat‐like superposition of lines at every single mass number, up to at least m/z 400. In the negative ion spectra the beats have a spacing of m/z 14, corresponding to a CH2‐unit. The high‐mass tails of the spectra extend well beyond m/z 5000, with similar slopes in the positive and the negative ion mass spectra. The negative spectra appear to be less affected by fragmentation products than the positive spectra. Fulvic acids (FAs) of different origin show distinctly different spectra, with mean masses ranging between m/z ≈ 450 and 580 (for a low‐mass cut‐off m/z 150). To further verify the ability of TOF‐SIMS to detect molecules and clusters with masses significantly above the maxima of the FA spectra, samples of glycyrrhizic acid (GA, as GA ammonium salt with molecular weight 840) were also analysed. Parent ions as well as multimers (GA)n were observed as positive and negative ions, up to n = 4 (m/z 3320). The results are compared with spectra recently obtained by other mass spectrometric techniques.

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Section: Resultscontrasting

confidence: 88%

Section: Resultssupporting

confidence: 85%

Section: Resultsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

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Characterisation of Fulvic Acids and Glycyrrhizic Acid by Time-of-Flight Secondary Ion Mass Spectrometry

Szymczak¹,

Wolf²,

Wittmaack³

2001

Acta hydrochim. hydrobiol.

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“…To date, little information on the m/z distribution for fingerprint identification is available. A comparison of desorption mass spectrometry techniques for the characterization of FA is given by Brown et al (1998). Fast atom bombardment (FAB) shows problems arising from the production of ions, whereas the laser desorption techniques (LD) appears more promising.…”

Section: Macromolecular Size and Weight Determinationmentioning

confidence: 99%

Structural characterization of aquatic humic substances ? The need for a multiple method approach

Abbt‐Braun

Lankes

Frimmel

2004

Aquatic Sciences - Research Across Boundaries

154

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An overview of different characterization methods and the possibilities for describing structural elements of humic substances from aqueous environments (HS, or refractory organic substances (ROS)) is given within this review. The application of different analytical methods for the qualitative and quantitative characterization of HS, including physical/chemical analysis (elemental analysis, acid/base titration), spectroscopic methods (UV/VIS, NMR, fluorescence, mass spectrometry), fractionation methods (gel chromatography, flow-fieldflow-fractionation), and degradation methods (oxidation, Aquatic Sciences pyrolysis, hydrolysis) are discussed. The paper focuses on the most commonly used chemical, spectroscopic and chromatographic methods used in the last few years. Aspects concerning information related to newer procedures are considered. Case studies representing results gained from reference samples isolated from brown water and wastewater effluents are given to cross-check results gained from several methods. The influence of different isolation procedures on the specific character of the fractions is also discussed.

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Emerging Concepts of the Compositions and Structures of Humic Substances

Hayes

1997

Humic Substances, Peats and Sludges

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Comparison of Desorption Mass Spectrometry Techniques for the Characterization of Fulvic Acid

Cited by 5 publications

References 28 publications

Characterisation of Fulvic Acids and Glycyrrhizic Acid by Time-of-Flight Secondary Ion Mass Spectrometry

Characterisation of Fulvic Acids and Glycyrrhizic Acid by Time-of-Flight Secondary Ion Mass Spectrometry

Structural characterization of aquatic humic substances ? The need for a multiple method approach

Emerging Concepts of the Compositions and Structures of Humic Substances

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