TY - JOUR
T1 - Relating Molecular Properties to the Persistence of Marine Dissolved Organic Matter with Liquid Chromatography-Ultrahigh-Resolution Mass Spectrometry
AU - Boiteau, Rene M.
AU - Corilo, Yuri E.
AU - Kew, William R.
AU - Dewey, Christian
AU - Alvarez Rodriguez, Maria Cristina
AU - Carlson, Craig A.
AU - Conway, Tim M.
N1 - Publisher Copyright:
© 2024 American Chemical Society.
PY - 2024/2/20
Y1 - 2024/2/20
N2 - Marine dissolved organic matter (DOM) contains a complex mixture of small molecules that eludes rapid biological degradation. Spatial and temporal variations in the abundance of DOM reflect the existence of fractions that are removed from the ocean over different time scales, ranging from seconds to millennia. However, it remains unknown whether the intrinsic chemical properties of these organic components relate to their persistence. Here, we elucidate and compare the molecular compositions of distinct DOM fractions with different lability along a water column in the North Atlantic Gyre. Our analysis utilized ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry at 21 T coupled to liquid chromatography and a novel data pipeline developed in CoreMS that generates molecular formula assignments and metrics of isomeric complexity. Clustering analysis binned 14 857 distinct molecular components into groups that correspond to the depth distribution of semilabile, semirefractory, and refractory fractions of DOM. The more labile fractions were concentrated near the ocean surface and contained more aliphatic, hydrophobic, and reduced molecules than the refractory fraction, which occurred uniformly throughout the water column. These findings suggest that processes that selectively remove hydrophobic compounds, such as aggregation and particle sorption, contribute to variable removal rates of marine DOM.
AB - Marine dissolved organic matter (DOM) contains a complex mixture of small molecules that eludes rapid biological degradation. Spatial and temporal variations in the abundance of DOM reflect the existence of fractions that are removed from the ocean over different time scales, ranging from seconds to millennia. However, it remains unknown whether the intrinsic chemical properties of these organic components relate to their persistence. Here, we elucidate and compare the molecular compositions of distinct DOM fractions with different lability along a water column in the North Atlantic Gyre. Our analysis utilized ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry at 21 T coupled to liquid chromatography and a novel data pipeline developed in CoreMS that generates molecular formula assignments and metrics of isomeric complexity. Clustering analysis binned 14 857 distinct molecular components into groups that correspond to the depth distribution of semilabile, semirefractory, and refractory fractions of DOM. The more labile fractions were concentrated near the ocean surface and contained more aliphatic, hydrophobic, and reduced molecules than the refractory fraction, which occurred uniformly throughout the water column. These findings suggest that processes that selectively remove hydrophobic compounds, such as aggregation and particle sorption, contribute to variable removal rates of marine DOM.
KW - Dissolved organic matter
KW - high-resolution mass spectrometry
KW - liquid chromatography
KW - ocean carbon cycle
KW - particle reactivity
UR - http://www.scopus.com/inward/record.url?scp=85187308480&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85187308480&partnerID=8YFLogxK
U2 - 10.1021/acs.est.3c08245
DO - 10.1021/acs.est.3c08245
M3 - Article
C2 - 38335252
AN - SCOPUS:85187308480
SN - 0013-936X
VL - 58
SP - 3267
EP - 3277
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 7
ER -