Humic substances were analysed by atmospheric pressure chemical ionisation (APCI) and electrospray ionisation (ESI) mass spectrometry in positive and negative modes. Using APCI the average m/z range of humic substances was reduced 5-fold compared to ESI. High-resolution time-of-flight mass spectrometry revealed the formation of multiply charged molecules in the ESI mode. Moreover, it was possible to obtain daughter ion mass spectra of humic substances by nanospray tandem mass spectrometry. The size-exclusion chromatography elution profile of humic substances was highly influenced by the pH of the analyte solution. By contrast, the pH had no significant influence on the observed mass spectra of humic substances.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/s0021-9673(01)00805-6 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Molecular Mechanisms of Humic Acid in Inhibiting Silica Scaling during Membrane Distillation.
Environ Sci Technol
January 2025
Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, P. R. China.
Membrane distillation (MD) efficiently desalinizes and treats high-salinity water as well as addresses the challenges in handling concentrated brines and wastewater. However, silica scaling impeded the effectiveness of MD for treating hypersaline water and wastewater. Herein, the effects of humic acid (HA) on silica scaling behavior during MD are systematically investigated.
View Article and Find Full Text PDFUnraveling the mechanisms underlying AOM-induced deterioration of the settling performance of algal floc.
Water Res
January 2025
School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China; Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China. Electronic address:
The influence of algal organic matter (AOM) on the settling performance of algal flocs remains poorly understood. To address this, we employed fractionation techniques based on molecular weight to isolate different AOM fractions and analyzed their effects on floc structure and settling performance. This involved comparing the concentrations, compositions, potentials, and functional groups of organic matter before and after coagulation-sedimentation.
View Article and Find Full Text PDFMunicipal anaerobic filter effluent treatment using advanced oxidation processes for potential use in unrestricted crop production.
J Environ Sci Health A Tox Hazard Subst Environ Eng
January 2025
Crop Science Discipline, University of KwaZulu-Natal, Pietermaritzburg, South Africa.
To meet wastewater treatment quality standards for reuse, integrating advanced oxidation processes (AOPs) with Decentralized Wastewater Treatment Systems (DEWATS) is promising. This study aimed to optimize AOPs (ozonolysis, UV photolysis, TiO photocatalysis) for polishing anaerobic filter (AF) effluent from DEWATS, as an alternative to constructed wetlands. Metrics included pathogen reduction efficiency, post-disinfection regrowth, and effects on physical parameters (pH, EC, turbidity), organic matter (soluble COD, BOD, DOC, humic), and nutrient concentration (ammonium, nitrates, ortho-P).
View Article and Find Full Text PDFHumic acid from vermicompost effectively regulates the redox status and mitigates the progression of experimental periodontitis.
Naunyn Schmiedebergs Arch Pharmacol
January 2025
Postgraduate Program in Health Sciences (PPGCS), Federal University of the Jequitinhonha and Mucuri Valleys (UFVJM), Diamantina, Brazil.
The progression of periodontal disease (PD) involves the action of oxidative stress mediators. Antioxidant agents may potentially attenuate the development of this condition. Thus, we aimed to evaluate the effects of different doses of humic acid (HA), extracted from biomass vermicomposting, on redox status and parameters related to PD progression in rats.
View Article and Find Full Text PDFAnalyze the impact of lignin depolymerization process and its products on humic substance formation.
Int J Biol Macromol
January 2025
College of Life Science, Northeast Agricultural University, 600 Changjiang Road, Harbin 150030, PR China. Electronic address:
This study aimed to identify types of lignin depolymerization products (LDP) and their role in humic substances (HS) formation, and little research has revealed which LDP could participate into HS formation during composting. Therefore, rice straw (RS), peanut straw (PS) and pine needles (PN) were selected for their different lignin structures to qualitatively and quantitative analyze LDP firstly. Qualitative results indicated that RS, PS and PN mainly produced LDP with G-type, common group and dimer structure.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!