{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T15:02:19Z","timestamp":1790002939434,"version":"4.0.1"},"reference-count":66,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T00:00:00Z","timestamp":1789603200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100007847","name":"Natural Science Foundation of Jilin Province","doi-asserted-by":"publisher","award":["YDZJ202101ZYTS111"],"award-info":[{"award-number":["YDZJ202101ZYTS111"]}],"id":[{"id":"10.13039\/100007847","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Iron oxide-mediated abiotic humification is critical for long-term soil organic carbon (SOC) stabilization. Goethite (\u03b1-FeOOH), the most thermodynamically stable iron oxyhydroxide in terrestrial ecosystems, is proposed to catalyze coupled Maillard reaction and polyphenol oxidation via surface hydroxyl and Fe(III) active sites. Nevertheless, the divergent interfacial regulatory mechanisms of glycine (Gly, N source) and glucose (Glu, C source) concentration gradients in goethite-catalyzed polyphenol-Maillard systems remain poorly understood. Two independent 360-h gradient incubation experiments were performed using synthetic goethite as a catalyst and catechol as a model polyphenol precursor to probe their concentration-dependent effects on short-term interfacial transformation kinetics and humic-like product properties. Kinetics, product properties, and underlying pathways were characterized via Gaussian and first-order asymptotic modeling, humic-like acid (HLA)\/fulvic-like acid (FLA) fractionation, elemental analysis, Fourier-transform infrared (FTIR) spectroscopy, and partial least squares structural equation modeling (PLS-SEM). Results showed that 0.12 mol\/L was the optimal concentration for both precursors to accelerate intermediate transformation. Gly elevated the baseline aromaticity parameter y0 by 108.87% (vs. 20.38% for Glu), while Glu increased the asymptotic maximum dissolved organic carbon (DOC) by 322.66% (vs. 78.02% for Gly). Moderate Gly (0.03 mol\/L) yielded the highest CHLA. Excessive precursors reduced the CHLA\/CFLA ratio via interfacial competitive adsorption and site occupation. The two precursors exerted opposing effects on the hydroxyl stretching peak of humic products, but both induced goethite surface reconstruction and activated iron-bearing surface functional groups. PLS-SEM confirmed precursor concentration as the dominant driver of humification kinetics. This study clarifies the distinct roles of Gly in aromatic cyclization and Glu as an aliphatic C donor during short-term mineral\u2013organic interfacial processes, providing quantitative benchmarks for optimizing artificial humus production.<\/jats:p>","DOI":"10.3390\/molecules31183302","type":"journal-article","created":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T14:12:09Z","timestamp":1789999929000},"page":"3302","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Glycine and Glucose Exert Divergent Concentration-Dependent Interfacial Regulatory Effects on Goethite-Catalyzed Polyphenol\u2013Maillard Abiotic Humification"],"prefix":"10.3390","volume":"31","author":[{"ORCID":"https:\/\/orcid.org\/0009-0007-7270-9210","authenticated-orcid":false,"given":"Nan","family":"Wang","sequence":"first","affiliation":[{"name":"College of Agriculture, Jilin Agricultural Science and Technology College, Jilin 132101, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-0337-100X","authenticated-orcid":false,"given":"Zihan","family":"Zheng","sequence":"additional","affiliation":[{"name":"College of Agriculture, Jilin Agricultural Science and Technology College, Jilin 132101, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"visualization","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"}]},{"given":"Mingshuo","family":"Wang","sequence":"additional","affiliation":[{"name":"College of Agriculture, Jilin Agricultural Science and Technology College, Jilin 132101, China"},{"name":"College of Agriculture, Jilin Agricultural University, Changchun 130118, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"}]},{"given":"Jiawen","family":"Peng","sequence":"additional","affiliation":[{"name":"College of Agriculture, Jilin Agricultural Science and Technology College, Jilin 132101, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"}]},{"given":"Houfu","family":"Chen","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8200-1696","authenticated-orcid":false,"given":"Shuai","family":"Wang","sequence":"additional","affiliation":[{"name":"College of Agriculture, Jilin Agricultural Science and Technology College, Jilin 132101, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"},{"role":"funding-acquisition","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1038\/s41545-024-00344-3","article-title":"Artificially regulated humification in creating humic-like biostimulators","volume":"7","author":"Sun","year":"2024","journal-title":"npj Clean Water"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"175496","DOI":"10.1016\/j.cej.2026.175496","article-title":"Unraveling the mechanisms of abiotic humification mediated by manganese dioxide polymorphs: The dual roles of oxygen vacancies and surface Mn(III)","volume":"535","author":"Ling","year":"2026","journal-title":"Chem. Eng. J."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"312","DOI":"10.1038\/s41586-023-06325-9","article-title":"Long-term organic carbon preservation enhanced by iron and manganese","volume":"621","author":"Moore","year":"2023","journal-title":"Nature"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"6717","DOI":"10.1038\/s41467-025-62016-1","article-title":"Geopolymerization threatens the persistence of organic carbon associated with iron in anoxic environments","volume":"16","author":"Zhao","year":"2025","journal-title":"Nat. Commun."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"130521","DOI":"10.1016\/j.cej.2021.130521","article-title":"Enhanced abiotic integrated polyphenol-Maillard humification by Mg\/Fe layered double hydroxide (LDH): Role of Fe(III)-polyphenol complexation","volume":"425","author":"Zhang","year":"2021","journal-title":"Chem. Eng. J."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"7628","DOI":"10.1038\/ncomms8628","article-title":"Towards a mechanistic understanding of carbon stabilization in manganese oxides","volume":"6","author":"Johnson","year":"2015","journal-title":"Nat. Commun."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"23923","DOI":"10.1007\/s11356-019-05664-3","article-title":"Structural characteristics of humic-like acid from microbial utilization of lignin involving different mineral types","volume":"26","author":"Wang","year":"2019","journal-title":"Environ. Sci. Pollut. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"141647","DOI":"10.1016\/j.chemosphere.2024.141647","article-title":"Using CuMgFe layered double oxide to replace laccase as a catalyst for abiotic humification","volume":"353","author":"Bui","year":"2024","journal-title":"Chemosphere"},{"key":"ref_9","first-page":"1620","article-title":"Impact of different oxygen concentrations on the spectral characteristics of iron oxide-enhanced abiotic humification products","volume":"44","author":"Zhang","year":"2024","journal-title":"Spectrosc. Spectr. Anal."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"217","DOI":"10.1016\/j.colsurfb.2010.07.012","article-title":"Polymerization of catechin catalyzed by Mn-, Fe- and Al-oxides","volume":"81","author":"Chen","year":"2010","journal-title":"Colloids Surf. B Biointerfaces"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"459","DOI":"10.1080\/00380768.1992.10415077","article-title":"Relative effectiveness of short-range ordered Mn(IV), Fe(III), Al, and Si oxides in the synthesis of humic acids from phenolic compounds","volume":"38","author":"Shindo","year":"1992","journal-title":"Soil Sci. Plant Nutr."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"16959","DOI":"10.1021\/acs.est.5c00204","article-title":"Oxygen vacancies on ferrihydrite promote surface polymerization of decomposing straw-derived dissolved organic matter: Implications for soil carbon sequestration","volume":"59","author":"Huang","year":"2025","journal-title":"Environ. Sci. Technol."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Wang, N., Cui, Y., Zhou, Y., Liu, P., Wang, M., Sun, H., Huang, Y., and Wang, S. (2024). Changes in the glucose concentration affect the formation of humic-like substances in polyphenol\u2013Maillard reactions involving gibbsite. Molecules, 29.","DOI":"10.3390\/molecules29092115"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Zhou, J., Zhou, Z., Yao, C., Zhang, Y., Ren, H., Lu, G., and Chen, H. (2024). Biochar catalysis for the enhanced abiotic humification of polyphenols: An important mechanism helping sequester carbon. Agronomy, 14.","DOI":"10.3390\/agronomy14091951"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Wang, N., Zhang, Q., Li, W., Bai, C., Song, Y., Wang, S., and Liu, Z. (2022). Effect of exogenous glucose at different concentrations on the formation of dark-brown humic-like substances in the Maillard reaction pathway based on the abiotic condensation of precursors involving \u03b4-MnO2. Sustainability, 14.","DOI":"10.3390\/su141811603"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Wang, N., Zhang, Q., Han, W., Bai, C., Hou, B., Liu, Y., and Wang, S. (2022). Chemical characteristics of dark-brown humic-like substances formed from the abiotic condensation of Maillard precursors with different glycine concentrations. Agronomy, 12.","DOI":"10.3390\/agronomy12092199"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Li, K., Han, Q., Wang, J., Dai, D., Gao, H., Gao, J., Wang, M., Sun, H., and Wang, S. (2025). Optimizing glycine concentration to enhance gibbsite-catalyzed abiotic humification of catechol and glucose. PLoS ONE, 20.","DOI":"10.1371\/journal.pone.0335528"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Kawa\u0142ko, D., Jamroz, E., Jerzykiewicz, M., and \u0106wiel\u0105g-Piasecka, I. (2023). Characteristics of humic acids in drained floodplain soils in temperate climates: A spectroscopic study. Sustainability, 15.","DOI":"10.3390\/su151411417"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1575","DOI":"10.1134\/S1064229321100148","article-title":"Elemental composition and structure of humic acids in virgin and arable soddy-podzolic soils of the Cis-Urals","volume":"54","author":"Zavyalova","year":"2021","journal-title":"Eurasian Soil Sci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"588","DOI":"10.1021\/acsomega.4c07196","article-title":"Obtaining microcellulose from solid agro-waste by ball mill assisted by light acid hydrolysis process","volume":"10","author":"Souza","year":"2025","journal-title":"ACS Omega"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1016\/j.jcis.2009.02.023","article-title":"Hydroxynaphthoic acid isomer sorption onto goethite","volume":"333","author":"Cooper","year":"2009","journal-title":"J. Colloid Interface Sci."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"286","DOI":"10.1016\/j.apcatb.2016.03.051","article-title":"Boron as a promoter in the goethite (\u03b1-FeOOH) phase: Organic compound degradation by Fenton reaction","volume":"192","author":"Mesquita","year":"2016","journal-title":"Appl. Catal. B Environ."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1016\/j.cej.2014.08.042","article-title":"Degradation of pCNB by Fenton like process using \u03b1-FeOOH","volume":"260","author":"Li","year":"2015","journal-title":"Chem. Eng. J."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"781","DOI":"10.1007\/s10812-021-01240-1","article-title":"Chemical transformations of flax shive lignin by the action of polysaccharide fermentation products","volume":"88","author":"Aleeva","year":"2021","journal-title":"J. Appl. Spectrosc."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"834","DOI":"10.20546\/ijcmas.2018.705.102","article-title":"Fourier transform infrared (FTIR) spectroscopy of soil humic and fulvic acids extracted from paddy land use system","volume":"7","author":"Reddy","year":"2018","journal-title":"Int. J. Curr. Microbiol. Appl. Sci."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"012013","DOI":"10.1088\/1755-1315\/1491\/1\/012013","article-title":"Study of structural, optical and photocatalytic properties of goethite","volume":"1491","author":"Frolova","year":"2025","journal-title":"IOP Conf. Ser. Earth Environ. Sci."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"27853","DOI":"10.1021\/acs.est.5c10850","article-title":"Surface charge heterogeneity and mechanisms of organic binding modes on an iron oxyhydroxide","volume":"59","author":"Wang","year":"2025","journal-title":"Environ. Sci. Technol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1060","DOI":"10.1021\/acsearthspacechem.4c00372","article-title":"Organic adsorption onto iron hydroxide and sulfide minerals: Implications for Ceres sample return analysis","volume":"9","author":"Martinez","year":"2025","journal-title":"ACS Earth Space Chem."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"101356","DOI":"10.1016\/j.fochx.2024.101356","article-title":"Maillard reaction intermediates in Chinese Baijiu and their effects on Maillard reaction related flavor compounds during aging","volume":"22","author":"Huang","year":"2024","journal-title":"Food Chem. X."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"100545","DOI":"10.1016\/j.rhisph.2022.100545","article-title":"The adsorption capacity of root exudate organic carbon onto clay mineral surface changes depending on clay mineral types and organic carbon composition","volume":"23","author":"Ndzana","year":"2022","journal-title":"Rhizosphere"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"116847","DOI":"10.1016\/j.lwt.2024.116847","article-title":"Effect of tea polyphenols on the formation of advanced glycation end products (AGEs), functional and structural properties of modified protein in Maillard reaction","volume":"210","author":"Li","year":"2024","journal-title":"LWT Food Sci. Technol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"90","DOI":"10.1007\/s11244-008-9109-9","article-title":"Steric effect on the catalytic performance of the selective oxidation of alcohols over novel crystalline Mo\u2013V\u2013O oxide","volume":"50","author":"Wang","year":"2008","journal-title":"Top. Catal."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"E429","DOI":"10.1152\/ajpendo.00093.2009","article-title":"The Randle cycle revisited: A new head for an old hat","volume":"297","author":"Hue","year":"2009","journal-title":"Am. J. Physiol. Endocrinol. Metab."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"263","DOI":"10.1016\/j.jcis.2010.09.023","article-title":"Adsorption mechanisms of glucose in aqueous goethite suspensions","volume":"353","author":"Olsson","year":"2011","journal-title":"J. Colloid Interface Sci."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Yi, S., Chen, X., Cao, X., Yi, B., and He, W. (2022). Influencing factors and environmental effects of interactions between goethite and organic matter: A critical review. Front. Environ. Sci., 10.","DOI":"10.3389\/fenvs.2022.1023277"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1038\/s43247-021-00301-9","article-title":"Carboxyl-richness controls organic carbon preservation during coprecipitation with iron (oxyhydr) oxides in the natural environment","volume":"2","author":"Curti","year":"2021","journal-title":"Commun. Earth Environ."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1016\/j.cej.2014.12.114","article-title":"Surface complexation modeling of coadsorption of antibiotic ciprofloxacin and Cu(II) and onto goethite surfaces","volume":"269","author":"Gu","year":"2015","journal-title":"Chem. Eng. J."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1827","DOI":"10.1021\/acs.est.7b04098","article-title":"Silicate binding and precipitation on iron oxyhydroxides","volume":"52","author":"Kanematsu","year":"2018","journal-title":"Environ. Sci. Technol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1016\/j.saa.2014.06.002","article-title":"Spectroscopic, potentiometric and theoretical studies of novel imino-phenolate chelators for Fe(III)","volume":"134","author":"Bera","year":"2014","journal-title":"Spectrochim. Acta A Mol. Biomol. Spectrosc."},{"key":"ref_40","first-page":"41","article-title":"Chemical composition of the precursor compounds and mechanisms of humic substances formation at the post-sedimentation stage of the organic compounds evolution","volume":"1-2","author":"Khokha","year":"2023","journal-title":"Geol. Geochem. Combust. Miner."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"124734","DOI":"10.1016\/j.cej.2020.124734","article-title":"Roles of oxygen and Mn(IV) oxide in abiotic formation of humic substances by oxidative polymerization of polyphenol and amino acid","volume":"393","author":"Zou","year":"2020","journal-title":"Chem. Eng. J."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"117655","DOI":"10.1016\/j.geoderma.2025.117655","article-title":"Iron-driven organic carbon sequestration in arid saline-alkali soils: Mechanisms of Fe-C coupling via reactive iron oxides and microaggregate stabilization","volume":"465","author":"Wang","year":"2026","journal-title":"Geoderma"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"87","DOI":"10.1002\/masy.200651312","article-title":"Oxidative coupling polymerization of substituted phenols with a copper amine catalyst immobilized within mesoporous silica","volume":"245","author":"Shibasaki","year":"2006","journal-title":"Macromol. Symp."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"11030","DOI":"10.1021\/acssuschemeng.2c03379","article-title":"Synthesis of oxygen-containing precursors of aviation fuel via carbonylation of the aqueous bio-oil fraction followed by C\u2013C coupling","volume":"10","author":"Sun","year":"2022","journal-title":"ACS Sustain. Chem. Eng."},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Wang, R., and Ben, H. (2020). Accelerated aging process of bio-oil model compounds: A mechanism study. Front. Energy Res., 8.","DOI":"10.3389\/fenrg.2020.00079"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"13107","DOI":"10.1021\/acs.langmuir.1c02261","article-title":"Competitive carboxylate\u2013silicate binding at iron oxyhydroxide surfaces","volume":"37","author":"Cheng","year":"2021","journal-title":"Langmuir"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"747","DOI":"10.1016\/j.orggeochem.2004.01.021","article-title":"Integration of the polyphenol and Maillard reactions into a unified abiotic pathway for humification in nature","volume":"35","author":"Jokic","year":"2004","journal-title":"Org. Geochem."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1007\/s11084-012-9266-5","article-title":"Oligomerization of glycine and alanine catalyzed by iron oxides: Implications for prebiotic chemistry","volume":"42","author":"Shanker","year":"2012","journal-title":"Orig. Life Evol. Biosph."},{"key":"ref_49","first-page":"1812","article-title":"Quantification of Fe(II) ions in the synthesis of polypyrrole by spectrophotometric detection","volume":"12","author":"More","year":"2023","journal-title":"Int. J. Sci. Res."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"4691","DOI":"10.1016\/S0043-1354(02)00204-X","article-title":"Oxidation of aromatic substrates in water\/goethite slurry by means of hydrogen peroxide","volume":"36","author":"Andreozzi","year":"2002","journal-title":"Water Res."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"667","DOI":"10.1111\/ejss.12459","article-title":"Competition and surface conditioning alter the adsorption of phenolic and amino acids on soil minerals","volume":"68","author":"Gao","year":"2017","journal-title":"Eur. J. Soil Sci."},{"key":"ref_52","unstructured":"Gao, J. (2017). Interactive Adsorption of Phenolic Acids and Amino Acids on Soil Minerals: Implications for the Formation and Properties of Soil Mineral\u2013Organic Associations. [Ph.D. Thesis, University of Amsterdam]. Available online: https:\/\/hdl.handle.net\/11245.1\/ade65efe-dfe2-4b1b-82ba-3394ccabd52f."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"129795","DOI":"10.1016\/j.biortech.2023.129795","article-title":"Mechanisms for enhanced lignin humification with reduced organic matter loss by goethite in biogas residue composting","volume":"389","author":"Wang","year":"2023","journal-title":"Bioresour. Technol."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"585","DOI":"10.1007\/s10163-015-0435-2","article-title":"Role of ferric oxide in abiotic humification enhancement of organic matter","volume":"19","author":"Zhang","year":"2015","journal-title":"J. Mater. Cycles Waste Manag."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"12087","DOI":"10.5194\/acp-25-12087-2025","article-title":"The effect of amino acids on the Fenton and photo-Fenton reactions in cloud water: Unraveling the dual role of glutamic acid","volume":"25","author":"Cheng","year":"2025","journal-title":"Atmos. Chem. Phys."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"116470","DOI":"10.1016\/j.jphotochem.2025.116470","article-title":"Degradation of fluoroquinolone antibiotic levofloxacin by UV-induced ferric ion photolysis in aqueous medium: The role of pH and chelation","volume":"467","year":"2025","journal-title":"J. Photochem. Photobiol. A Chem."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"104539","DOI":"10.1016\/j.arabjc.2022.104539","article-title":"Aggregation process of fine hematite particles suspension using xanthan gum in the presence of Fe(III)","volume":"16","author":"Yang","year":"2023","journal-title":"Arab. J. Chem."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"380","DOI":"10.1016\/j.jcis.2003.12.049","article-title":"Kinetic study on the sorption of dissolved natural organic matter onto different aquifer materials: The effects of hydrophobicity and functional groups","volume":"274","author":"Chi","year":"2004","journal-title":"J. Colloid Interface Sci."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"323","DOI":"10.1180\/002646101300119439","article-title":"A view of reactions at mineral surfaces from the aqueous phase","volume":"65","author":"Casey","year":"2001","journal-title":"Mineral. Mag."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1006\/jcis.2001.7927","article-title":"Modeling the binding of benzenecarboxylates by goethite: The ligand and charge distribution model","volume":"244","author":"Filius","year":"2001","journal-title":"J. Colloid Interface Sci."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1016\/j.molstruc.2010.08.032","article-title":"Spectroscopic investigations of humic-like acids formed via polycondensation reactions between glycine, catechol and glucose in the presence of natural zeolites","volume":"982","author":"Fukuchi","year":"2010","journal-title":"J. Mol. Struct."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"12378","DOI":"10.1038\/s41598-023-39181-8","article-title":"Evidence for the formation of fused aromatic ring structures in an organic soil profile in the early diagenesis","volume":"13","author":"Gamage","year":"2023","journal-title":"Sci. Rep."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"100077","DOI":"10.1016\/j.ceja.2020.100077","article-title":"Is the traditional alkali extraction method valid in isolating chemically distinct humic acid?","volume":"6","author":"Zou","year":"2021","journal-title":"Chem. Eng. J. Adv."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"2047","DOI":"10.1002\/jctb.7706","article-title":"Phosphate buffer-driven precursor polycondensation to promote fermentative humification","volume":"99","author":"Li","year":"2024","journal-title":"J. Chem. Technol. Biotechnol."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"7410","DOI":"10.1021\/acs.est.9b00950","article-title":"Abiotic formation of humic-like substances through freezing-accelerated reaction of phenolic compounds and nitrite","volume":"53","author":"Min","year":"2019","journal-title":"Environ. Sci. Technol."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"603","DOI":"10.1016\/j.ecoenv.2018.09.057","article-title":"The impact of varying abiotic humification conditions and the resultant structural characteristics on the copper complexation ability of synthetic humic-like acids in aquatic environments","volume":"165","author":"Yang","year":"2018","journal-title":"Ecotoxicol. Environ. Saf."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/31\/18\/3302\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T14:14:30Z","timestamp":1790000070000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/31\/18\/3302"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,17]]},"references-count":66,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["molecules31183302"],"URL":"https:\/\/doi.org\/10.3390\/molecules31183302","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,17]]}}}