[1]

Galloway JN, Townsend AR, Erisman JW, Bekunda M, Cai Z, et al. 2008. Transformation of the nitrogen cycle: recent trends, questions, and potential solutions. Science 320:889−892

doi: 10.1126/science.1136674
[2]

Gu B, Zhang L, Van Dingenen R, Vieno M, Van Grinsven HJ, et al. 2021. Abating ammonia is more cost-effective than nitrogen oxides for mitigating PM2.5 air pollution. Science 374:758−762

doi: 10.1126/science.abf8623
[3]

Kirkby J, Curtius J, Almeida J, Dunne E, Duplissy J, et al. 2011. Role of sulphuric acid, ammonia and galactic cosmic rays in atmospheric aerosol nucleation. Nature 476:429−433

doi: 10.1038/nature10343
[4]

Stokstad E. 2014. Ammonia pollution from farming may exact hefty health costs. Science 343:238

doi: 10.1126/science.343.6168.238
[5]

Yang F, Tan J, Zhao Q, Du Z, He K, et al. 2011. Characteristics of PM2.5 speciation in representative megacities and across China. Atmospheric Chemistry and Physics 11:5207−5219

doi: 10.5194/acp-11-5207-2011
[6]

Wang G, Zhang R, Gomez ME, Yang L, Levy Zamora M, et al. 2016. Persistent sulfate formation from London Fog to Chinese haze. Proceedings of the National Academy of Sciences of the United States of America 113:13630−13635

doi: 10.1073/pnas.1616540113
[7]

Roohollahi H, Mirzaei M, Bagheri H. 2024. Chapter thirteen − Ammonia: emission, atmospheric transport, and deposition. In Progresses in Ammonia: Science, Technology and Membranes, eds. Basile A, Rahimpour MR. Amsterdam: Elsevier. pp. 295−323 doi: 10.1016/b978-0-323-88516-4.00012-3

[8]

Elliott EM, Yu Z, Cole AS, Coughlin JG. 2019. Isotopic advances in understanding reactive nitrogen deposition and atmospheric processing. Science of The Total Environment 662:393−403

doi: 10.1016/j.scitotenv.2018.12.177
[9]

Bhattarai N, Wang S, Pan Y, Xu Q, Zhang Y, et al. 2021. δ15N-stable isotope analysis of NHx: an overview on analytical measurements, source sampling and its source apportionment. Frontiers of Environmental Science & Engineering 15:126

doi: 10.1007/s11783-021-1414-6
[10]

Pan Y, Tian S, Liu D, Fang Y, Zhu X, et al. 2016. Fossil fuel combustion-related emissions dominate atmospheric ammonia sources during severe haze episodes: evidence from 15N-stable isotope in size-resolved aerosol ammonium. Environmental Science & Technology 50:8049−8056

doi: 10.1021/acs.est.6b00634
[11]

Song L, Wang A, Li Z, Kang R, Walters WW, et al. 2024. Large seasonal variation in nitrogen isotopic abundances of ammonia volatilized from a cropland ecosystem and implications for regional NH3 source partitioning. Environmental Science & Technology 58:1177−1186

doi: 10.1021/acs.est.3c08800
[12]

Gu M, Zeng Y, Walters WW, Sun Q, Fang Y, et al. 2025. Enhanced nonagricultural emissions of ammonia influence aerosol ammonium in an urban atmosphere: evidence from kinetic versus equilibrium isotope fractionation controls on nitrogen. Environmental Science & Technology 59:650−658

doi: 10.1021/acs.est.4c09103
[13]

Freyer HD. 1978. Seasonal trends of NH4+ and NO3 nitrogen isotope composition in rain collected at Jülich, Germany. Tellus 30:83−92

doi: 10.3402/tellusa.v30i1.10319
[14]

Heaton THE. 1987. 15N/14N ratios of nitrate and ammonium in rain at Pretoria, South Africa. Atmospheric Environment (1967) 21:843−852

doi: 10.1016/0004-6981(87)90080-1
[15]

Xiao H, Ding S, Li X. 2024. Sources of NH4+ in PM2.5 and their seasonal variations in urban Tianjin China: new insights from the seasonal δ15N values of NH3 source. Journal of Geophysical Research: Atmospheres 129:e2023JD040169

doi: 10.1029/2023jd040169
[16]

Pacholski A. 2016. Calibrated passive sampling − multi-plot field measurements of NH3 emissions with a combination of dynamic tube method and passive samplers. Journal of Visualized Experiments 109:e53273

doi: 10.3791/53273
[17]

Robinson D. 2001. δ15N as an integrator of the nitrogen cycle. Trends in Ecology & Evolution 16:153−162

doi: 10.1016/S0169-5347(00)02098-X
[18]

Soto-Herranz M, Sánchez-Báscones M, Antolín-Rodríguez JM, Martín-Ramos P. 2022. Evaluation of different capture solutions for ammonia recovery in suspended gas permeable membrane systems. Membranes 12:572

doi: 10.3390/membranes12060572
[19]

Damtie MM, Volpin F, Yao M, Tijing LD, Hailemariam RH, et al. 2021. Ammonia recovery from human urine as liquid fertilizers in hollow fiber membrane contactor: effects of permeate chemistry. Environmental Engineering Research 26:190523

doi: 10.4491/eer.2019.523
[20]

Deng X, Xu T, Xue L, Hou P, Xue L, et al. 2023. Effects of warming and fertilization on paddy N2O emissions and ammonia volatilization. Agriculture, Ecosystems & Environment 347:108361

doi: 10.1016/j.agee.2023.108361
[21]

Xu X, Ouyang X, Gu Y, Cheng K, Smith P, et al. 2021. Climate change may interact with nitrogen fertilizer management leading to different ammonia loss in China's croplands. Global Change Biology 27:6525−6535

doi: 10.1111/gcb.15874
[22]

Ti C, Ma S, Peng L, Tao L, Wang X, et al. 2021. Changes of δ15N values during the volatilization process after applying urea on soil. Environmental Pollution 270:116204

doi: 10.1016/j.envpol.2020.116204
[23]

Liu D, Fang Y, Tu Y, Pan Y. 2014. Chemical method for nitrogen isotopic analysis of ammonium at natural abundance. Analytical Chemistry 86:3787−3792

doi: 10.1021/ac403756u
[24]

Felix JD, Elliott EM, Gish TJ, McConnell LL, Shaw SL. 2013. Characterizing the isotopic composition of atmospheric ammonia emission sources using passive samplers and a combined oxidation-bacterial denitrifier approach. Rapid Communications in Mass Spectrometry 27:2239−2246

doi: 10.1002/rcm.6679
[25]

Camargo Valero MA, Mara DD. 2007. Nitrogen removal via ammonia volatilization in maturation ponds. Water Science and Technology 55:87−92

doi: 10.2166/wst.2007.349
[26]

Zhou W, Tian Y, Cao Y, Yin B. 2011. A comparative study on two methods for determination of ammonia volatilization. Acta Pedologica Sinica 48:1090−1095

doi: 10.11766/trxb201003050082
[27]

Xiao HW, Wu JF, Luo L, Liu C, Xie YJ, et al. 2020. Enhanced biomass burning as a source of aerosol ammonium over cities in central China in autumn. Environmental Pollution 266:115278

doi: 10.1016/j.envpol.2020.115278
[28]

Pan Y, Tian S, Liu D, Fang Y, Zhu X, et al. 2018. Isotopic evidence for enhanced fossil fuel sources of aerosol ammonium in the urban atmosphere. Environmental Pollution 238:942−947

doi: 10.1016/j.envpol.2018.03.038
[29]

Chang Y, Zou Z, Zhang Y, Deng C, Hu J, et al. 2019. Assessing contributions of agricultural and nonagricultural emissions to atmospheric ammonia in a Chinese megacity. Environmental Science & Technology 53:1822−1833

doi: 10.1021/acs.est.8b05984
[30]

Lamothe A, Savarino J, Ginot P, Soussaintjean L, Gautier E, et al. 2023. An extraction method for nitrogen isotope measurement of ammonium in a low-concentration environment. Atmospheric Measurement Techniques 16:4015−4030

doi: 10.5194/amt-16-4015-2023
[31]

Panday D, Mikha MM, Maharjan B. 2020. Coal char affects soil pH to reduce ammonia volatilization from sandy loam soil. Agrosystems, Geosciences & Environment 3:e20123

doi: 10.1002/agg2.20123
[32]

Mandal S, Donner E, Vasileiadis S, Skinner W, Smith E, et al. 2018. The effect of biochar feedstock, pyrolysis temperature, and application rate on the reduction of ammonia volatilisation from biochar-amended soil. Science of The Total Environment 627:942−950

doi: 10.1016/j.scitotenv.2018.01.312
[33]

Cejudo E, Schiff SL. 2018. Nitrogen isotope fractionation factors (α) measured and estimated from the volatilisation of ammonia from water at pH 9.2 and pH 8.5. Isotopes in Environmental and Health Studies 54:642−655

doi: 10.1080/10256016.2018.1526792
[34]

Bai X, Ti C, Yan X, Li M, Tao L, et al. 2022. Natural abundance of a volatile nitrogen isotope of ammonia under different land uses. Journal of Agro-Environment Science 41:1590−1597

doi: 10.11654/jaes.2022-0016
[35]

Chang Y, Liu X, Deng C, Dore AJ, Zhuang G. 2016. Source apportionment of atmospheric ammonia before, during, and after the 2014 APEC summit in Beijing using stable nitrogen isotope signatures. Atmospheric Chemistry and Physics 16:11635−11647

doi: 10.5194/acp-16-11635-2016
[36]

Bhattarai N, Wang S, Xu Q, Dong Z, Chang X, et al. 2020. Sources of gaseous NH3 in urban Beijing from parallel sampling of NH3 and NH4+, their nitrogen isotope measurement and modeling. Science of The Total Environment 747:141361

doi: 10.1016/j.scitotenv.2020.141361
[37]

Ma R, Zou J, Han Z, Yu K, Wu S, et al. 2021. Global soil-derived ammonia emissions from agricultural nitrogen fertilizer application: a refinement based on regional and crop-specific emission factors. Global Change Biology 27:855−867

doi: 10.1111/gcb.15437
[38]

Xu R, Tian H, Pan S, Prior SA, Feng Y, et al. 2019. Global ammonia emissions from synthetic nitrogen fertilizer applications in agricultural systems: empirical and process-based estimates and uncertainty. Global Change Biology 25:314−326

doi: 10.1111/gcb.14499
[39]

Huang S, Elliott EM, Felix JD, Pan Y, Liu D, et al. 2019. Seasonal pattern of ammonium 15N natural abundance in precipitation at a rural forested site and implications for NH3 source partitioning. Environmental Pollution 247:541−549

doi: 10.1016/j.envpol.2019.01.023
[40]

Nikolenko O, Jurado A, Borges AV, Knӧller K, Brouyѐre S. 2018. Isotopic composition of nitrogen species in groundwater under agricultural areas: a review. Science of The Total Environment 621:1415−1432

doi: 10.1016/j.scitotenv.2017.10.086
[41]

Choi WJ, Arshad MA, Chang SX, Kim TH. 2006. Grain 15N of crops applied with organic and chemical fertilizers in a four-year rotation. Plant and Soil 284:165−174

doi: 10.1007/s11104-006-0038-8
[42]

Savard MM, Cole A, Smirnoff A, Vet R. 2017. δ15N values of atmospheric N species simultaneously collected using sector-based samplers distant from sources – isotopic inheritance and fractionation. Atmospheric Environment 162:11−22

doi: 10.1016/j.atmosenv.2017.05.010
[43]

Chalk PM, Inácio CT, Chen D. 2019. An overview of contemporary advances in the usage of 15N natural abundance (δ15N) as a tracer of agro-ecosystem N cycle processes that impact the environment. Agriculture, Ecosystems & Environment 283:106570

doi: 10.1016/j.agee.2019.106570
[44]

Chen X, Zhao T, Xiao C, Guo X, Nie X, et al. 2024. Stable isotopic characterization and sources of ammonium in wet deposition at the Danjiangkou Reservoir. Atmospheric Pollution Research 15:102272

doi: 10.1016/j.apr.2024.102272
[45]

Zhang Y, Ma X, Tang A, Fang Y, Misselbrook T, et al. 2023. Source apportionment of atmospheric ammonia at 16 sites in China using a Bayesian isotope mixing model based on δ15N-NHx signatures. Environmental Science & Technology 57:6599−6608

doi: 10.1021/acs.est.2c09796
[46]

Wang C, Liu Z, Zhang X, Zhang L, Zhou F, et al. 2025. Managing ammonia for multiple benefits based on verified high-resolution emission inventory in China. Environmental Science & Technology 59:5131−5144

doi: 10.1021/acs.est.4c12558
[47]

Mgelwa AS, Song L, Fan M, Li Z, Zhang Y, et al. 2022. Isotopic imprints of aerosol ammonium over the north China plain. Environmental Pollution 315:120376

doi: 10.1016/j.envpol.2022.120376
[48]

Lim S, Hwang J, Lee M, Czimczik CI, Xu X, et al. 2022. Robust evidence of 14C, 13C, and 15N analyses indicating fossil fuel sources for total carbon and ammonium in fine aerosols in Seoul megacity. Environmental Science & Technology 56:6894−6904

doi: 10.1021/acs.est.1c03903