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Over the past 50 years, fossil fuel consumption has increased dramatically, rising approximately eight-fold since 1950 and doubling since 1980. This surge has led to increased emissions of brown carbon (BrC) into the atmosphere, which are subsequently deposited onto oceans and land through dry or wet deposition processes. However, the source-specific fluxes of atmospheric organic carbon (OC) and BrC into the ocean are not adequately represented in the global carbon cycle. For the first time, we calculated BrC concentration using the optical intensity of organic matter and determined the global wet depositional flux of fossil fuel-derived BrC. Using the ratio of humic-like substances to OC fluxes, we estimated the global wet deposition of fossil fuel-derived BrC to be 2.0 ± 0.6 Tg C yr−1. Of this amount, the flux into oceans (0.7 ± 0.2 Tg C yr−1) represents 1.6% of the production rate of refractory dissolved organic carbon (RDOC) in the ocean (43 Tg yr−1). Notably, an increase in the proportion of fossil fuel-derived BrC in atmospheric OC may change the composition of OC in precipitation, resulting in a more refractory composition, which deviates from previously established paradigms. Our findings indicate that the flux of fossil fuel-derived RDOC from the atmosphere into the ocean, which is inadequately represented in current global DOC cycling models, may play a significant role in oceanic carbon cycles. These findings necessitate reconsidering our understanding of oceanic carbon cycling and highlight the need to improve existing models to better account for these newly identified processes and their potential impacts on global carbon dynamics. [Display omitted] • First calculation of BrC concentration using optical intensity of organic matter. • Global wet deposition of fossil fuel-derived BrC estimated at 2.0 ± 0.6 Tg C yr−1. • Ocean flux of fossil fuel-derived BrC is 1.6% of refractory DOC production rate. • BrC from fossil fuels may shift precipitation OC towards more refractory composition. • Fossil fuel-derived refractory DOC flux may significantly impact oceanic carbon cycles. [ABSTRACT FROM AUTHOR]

Complex separation and analytical techniques, like gas and liquid chromatography (GC, LC) and, more recently, capillary electrophoresis (CE) are developing and adapting their systems to respond to one major demand, the environmental analysis and monitoring. Different analytical methods used for atmospheric samples are comparatively presented and discussed. Although CE is suitable for hyphenated techniques, likewise GC and LC, by coupling with mass spectroscopy (MS), nuclear magnetic resonance (NMR), Raman spectroscopy, giving more specific identification information for environmental samples resolving, CE-MS techniques was not found to be specific for atmospheric compounds analysis. The paper presents capillary electrophoresis as a suitable tool for environmental analysis, with application for atmospheric aerosols. Introduction on CE principles and separation modes, as well as different electrophoretic buffers resolving ionic inorganic and organic compounds, are presented. A comparison between CE and ion chromatography (IC) is given. [ABSTRACT FROM AUTHOR]