Factors that affect molecular weight distribution of Suwannee river fulvic acid as determined by electrospray ionization/mass spectrometry

Rostad, Colleen E.; Leenheer, Jerry A.

doi:10.1016/j.aca.2004.06.065

Cited by 80 publications

(85 citation statements)

References 16 publications

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“…This result is in good agreement with other literature data (Lingbo et al, 2005;Pfeifer et al, 2001;Rostad and Leenheer, 2004). Similarly to our results, Persson et al (2000) and Pfeifer et al (2001) observed at least one order of magnitude higher total ion current in the negative mode when analysing aquatic humic substances by ESI-MS.…”

Section: Maldi-tof-mssupporting

confidence: 93%

“…Some molecules could be multiply charged, which would distort the molecular weight distribution (Rostad and Leenheer, 2004).…”

Section: Esi-q-msmentioning

confidence: 99%

“…Parameters found to considerably affect molecular mass determinations by ESI-MS of humic substances include solution concentration, pH, ionic strength, and complexity (Brown and Rice, 2000;Persson et al, 2000;Piccolo and Spiteller, 2003;Rostad and Leenheer, 2004). Likewise, m/z ion distribution range and intensity may vary greatly as a function of spray solvent composition, positive versus negative ion detection mode, and cone voltage (Brown and Rice, 2000;Nebbioso et al, 2010;Persson et al, 2000;Rostad and Leenheer, 2004;These and Reemtsma, 2003).…”

Section: Introductionmentioning

confidence: 99%

“…Likewise, m/z ion distribution range and intensity may vary greatly as a function of spray solvent composition, positive versus negative ion detection mode, and cone voltage (Brown and Rice, 2000;Nebbioso et al, 2010;Persson et al, 2000;Rostad and Leenheer, 2004;These and Reemtsma, 2003).…”

Section: Introductionmentioning

confidence: 99%

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Mass spectrometric techniques for characterisation of platinum–humic substance complexes in soil and street dust samples

Lyubomirova

Djingova

2013

Chemical Speciation & Bioavailability

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Increased platinum concentrations have been detected in environmental samples since the introduction of catalytic converters in Europe. It was previously believed that PGE are relatively inert and that the soluble fraction of automobile catalyst emitted PGE is only a few percent. However, new studies suggested that metallic Pt is oxidised in the soil and that the majority of the Pt species could be humic substance complexes.The aim of the present paper is the characterisation of platinum-humic acid complexes in spiked soil and street dust samples. A number of different soft ionisation mass spectrometric techniques, such as ESI-Q-MS, ESI-ION TRAP-MS and MALDI-TOF-MS have been tested. The ESI mass spectra of the soil humic acids were characterised by high complexity and irreproducibility.MALDI-TOF-MS was used for humic acid complexes characterisation in positive and negative modes. Positive ionisation was less effective and produced more simple and less informative spectra than negative ionisation. Two different MALDI matrices (CHCA, DHBA) were tested for use with humic substances. DHBA yielded better results, exhibiting superior ionisation efficiency, low spectral background and the matrix peaks were almost completely suppressed causing no interferences with identified analyte peaks. The application of MALDI-TOF-MS shows its suitability for humic substance characterisation. The comparison of the MALDI-spectra of humic acids, extracted from spiked and native soil proved that Pt undergoes transformation in the environment to humic acid complexes.

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Section: Maldi-tof-mssupporting

confidence: 93%

“…Some molecules could be multiply charged, which would distort the molecular weight distribution (Rostad and Leenheer, 2004).…”

Section: Esi-q-msmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Mass spectrometric techniques for characterisation of platinum–humic substance complexes in soil and street dust samples

Lyubomirova

Djingova

2013

Chemical Speciation & Bioavailability

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“…Previous studies have determined that water/methanol mixtures yield higher quality mass spectra (Kujawinski et al, 2002b;Rostad and Leenheer, 2004), therefore, the C 18 -extracts of aerosol WSOC were diluted by 25% with LC-MS grade water. In order to increase the ionization efficiency, a small amount of ammonium hydroxide (<0.1% total volume) was added immediately prior to ESI, raising the pH of the sample to approximately 8.…”

Section: Methodsmentioning

confidence: 99%

Technical Note: Molecular characterization of aerosol-derived water soluble organic carbon using ultrahigh resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry

et al. 2008

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Abstract. Despite the acknowledged relevance of aerosolderived water-soluble organic carbon (WSOC) to climate and biogeochemical cycling, characterization of aerosol WSOC has been limited. Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) was utilized in this study to provide detailed molecular level characterization of the high molecular weight (HMW; m/z>223) component of aerosol-derived WSOC collected from rural sites in Virginia and New York, USA. More than 3000 peaks were detected by ESI FT-ICR MS within a m/z range of 223-600 for each sample. Approximately 86% (Virginia) and 78% (New York) of these peaks were assigned molecular formulas using only carbon (C), hydrogen (H), oxygen (O), nitrogen (N), and sulfur (S) as elemental constituents. H/C and O/C molar ratios were plotted on van Krevelen diagrams and indicated a strong contribution of lignin-like and lipid-like compounds to the aerosol-derived WSOC samples. Approximately 1-4% of the peaks in the aerosol-derived WSOC mass spectra were classified as black carbon (BC) on the basis of double bond equivalents calculated from the assigned molecular formulas. In addition, several high-magnitude peaks in the mass spectra of samples from both sites corresponded to molecular formulas proposed in previous secondary organic aerosol (SOA) laboratory investigations indicating that SOAs are important constituents of the WSOC. Overall, ESI FT-ICR MS provides a level of resolution adequate for detailed compositional and source information of the HMW constituents of aerosolderived WSOC.

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Characterization of humic‐like substances in Arctic aerosols

et al. 2014

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Humic-like substances (HULIS) are a complex group of relatively high molecular weight organic compounds which contribute considerably to the mass of organic carbon (OC) and influence the light-absorbing properties of aerosols. In this work, HULIS were investigated for the first time in the high-Arctic atmosphere, focusing on the chemical characterization and mass contribution of HULIS to the total suspended particle (TSP) mass using weekly aerosol samples collected at Station Nord, northeast Greenland every fourth week during 2010. Average HULIS-C concentration was 11 ng C m À3 during the darker months (November-April) and 4 ng C m À3during the other months (May-October) with an annual mass concentration of 0.02 ± 0.01 μg m À3. HULIS-C contributed to 3-16% of water-soluble organic carbon (WSOC), whereas HULIS accounted for 0.7-4.1% of TSP mass, with TSP typically below 1.0 μg m À3. Concentrations of OC, WSOC, HULIS, selected HULIS functional groups (carboxylic acids, aromatic carboxylic acids, and organosulfates) and levoglucosan overlapped with the typical Arctic haze pattern with elevated concentrations during winter to early spring. The aromatic carboxylic acid portion accounted for a larger share of total carboxylic acid of HULIS during the darker months (7%) compared to the brighter months (3%). The more abundant aromatic carboxylic acid functional groups and the moderate correlation between HULIS and levoglucosan concentrations during the darker months both indicate that biomass burning aerosols and thereby emissions of aromatic compounds could contribute to HULIS in the Arctic, especially during late winter. During the brighter months, relatively higher average molecular weight of HULIS was observed.

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Factors that affect molecular weight distribution of Suwannee river fulvic acid as determined by electrospray ionization/mass spectrometry

Cited by 80 publications

References 16 publications

Mass spectrometric techniques for characterisation of platinum–humic substance complexes in soil and street dust samples

Mass spectrometric techniques for characterisation of platinum–humic substance complexes in soil and street dust samples

Technical Note: Molecular characterization of aerosol-derived water soluble organic carbon using ultrahigh resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry

Characterization of humic‐like substances in Arctic aerosols

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