Hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry for acidic herbicides and metabolites analysis in fresh water
Theoretical papers and environmental applications of hydrophilic interaction liquid chromatography (HILIC) have been published for a wide range of analytes, but to our knowledge, no study focused on acidic herbicides (e.g., triketones, phenoxy acids, sulfonylurea, and acidic metabolites of chloroacetanilides). Matrix effects are the main obstacle to natural sample analysis by liquid chromatography coupled with tandem mass spectrometry (MS) via an electrospray ionization (ESI) interface. Therefore, we paid particular attention on limiting interference by (i) adapting the emerging HILIC technique, which is generally considered more sensitive than conventional reversed phase liquid chromatography and (ii) optimizing the solid phase extraction (SPE) step using a design of experiment. A rapid and reliable off line SPE-HILIC-ESI-MS/MS method was thus developed for the quantification of acidic herbicides in fresh water, with limits of quantifications (LOQs) ranging from 5 to 22 ng l1 . Then, the analysis of freshwater samples highlighted the robustness of the method, and the importance of the chloroacetanilides metabolites among the studied analytes.
(Environmental Science and Pollution Research. vol. 22, n° 0944-1344, pp. 3988-3996, 26/10/2026)
UR EABX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Statistical modeling of Southern Ocean marine diatom proxy and winter sea ice data: Model comparison and developments
We compare the performance of the modern analog technique (MAT), the Imbrie and Kipp transfer function (IKTF), the generalized additive model (GAM) and weighted averaging partial least squares (WA PLS) on a southern hemisphere diatom relative abundance and winter sea ice concentration training data set. All relevant model assumptions are tested with a random 10-fold cross-validation, whilst a hold out cross-validation tested the explanatory power of each model on spatially independent validation data. We used auto correlograms on model residuals, variance partitioning, and principal coordinates analysis of neighbor matrices (PCNM) to investigate the importance of the spatial structure of our training database. A set of hierarchical logistic regression models (or Huisman–Olff–Fresco models) are used to infer the response of each diatom species along the winter sea ice gradient. Our analyses suggest that IKTF is an inappropriate sea ice estimation approach as its underlying statistical assumptions do not hold and the fit of IKTF to our data under cross-validation was poor. We conclude that MAT may be biased by spatial autocorrelation, and together with IKTF fails to provide unbiased estimates of winter sea ice. We find GAM and WA PLS are more appropriate than IKTF and MAT for the estimation of paleo winter sea ice cover throughout the Southern Ocean. However, as WA PLS is based on a unimodal species response, which is rarely exhibited by diatoms along the winter sea ice gradient, we ultimately advocate the application of GAM. GAM only uses diatoms with a statistically significant association, and ecologically based link, with sea ice. GAM outperformed all other models under cross-validation in terms of performance statistics, the fit of GAM to the training dataset and diagnostic tests for model assumptions. We also demonstrate that GAM provides a more detailed and potentially more accurate (based on a comparison with New Zealand and southeast Australian paleo climatic records) paleo winter sea ice record for the southwestern Pacific Ocean in comparison with IKTF, MAT and WA PLS.
(Progress in Oceanography. vol. 131, n° 0079-6611, pp. 100-112, 26/10/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
First records of winter sea ice concentration in the southwest Pacific sector of the Southern Ocean
We use a Generalized Additive Model (GAM) to provide the first winter sea ice concentration record from two cores located within the southwest Pacific sector of the Southern Ocean. To compliment the application of GAM, a time series analysis on satellite records of sea ice concentration data was used to extend the standard 13.25 year time series used for paleoceanography. After comparing GAM sea ice estimates with previously published paleo sea ice data we then focus on a new paleo winter sea ice record for marine sediment core E27-23 (59°37.1'S, 155°14.3'E), allowing us to provide a more comprehensive view of winter sea ice dynamics for the southwest Pacific Ocean. The paleo winter sea ice concentration estimates provide the first suggestion that winter sea ice within the southwestern Pacific might have expanded during the Antarctic Cold Reversal. Throughout the Holocene, core E27-23 documents millennial scale variability in paleo winter sea ice coverage within the southwest Pacific. Holocene winter sea ice expansion may have resulted from the Laurentide Ice Sheet deglaciation, increased intensity of the westerly winds, as well as a northern migration of the Subtropical and/or Sub-Antarctic Fronts. Brief consideration is given to the development of a paleo summer sea ice proxy. We conclude that there is no evidence that summer sea ice ever existed at core sites SO136-111 and E27-23 over the last 220 and 52,000 years, respectively.
(Paleoceanography. vol. 30, n° 0883-8305, pp. 1525-1539, 26/10/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UTAS, ANSTO
Recent changes in north-west Greenland climate documented by NEEM shallow ice core data and simulations, and implications for past-temperature reconstructions
Combined records of snow accumulation rate, δ 18 O and deuterium excess were produced from several shallow ice cores and snow pits at NEEM (North Greenland Eemian Ice Drilling), covering the period from 1724 to 2007. They are used to investigate recent climate variability and characterise the isotope–temperature relationship. We find that NEEM records are only weakly affected by inter-annual changes in the North Atlantic Oscillation. Decadal δ 18 O and accumulation variability is related to North Atlantic sea surface temperature and is enhanced at the beginning of the 19th century. No long-term trend is observed in the accumulation record. By contrast, NEEM δ 18 O shows multidecadal increasing trends in the late 19th century and since the 1980s. The strongest annual positive δ 18 O values are recorded at NEEM in 1928 and 2010, while maximum accumulation occurs in 1933. The last decade is the most enriched in δ 18 O (warmest), while the 11-year periods with the strongest depletion (coldest) are depicted at NEEM in 1815–1825 and 1836–1846, which are also the driest 11-year periods. The NEEM accumulation and δ 18 O records are strongly correlated with outputs from atmospheric models, nudged to atmospheric reanalyses. Best performance is observed for ERA reanalyses. Gridded temperature reconstructions, instrumental data and model outputs at NEEM are used to estimate the multidecadal accumulation–temperature and δ 18 O– temperature relationships for the strong warming period in 1979–2007. The accumulation sensitivity to temperature is estimated at 11 ± 2 % • C −1 and the δ 18 O–temperature slope at 1.1 ± 0.2 ‰ • C −1 , about twice as large as previously used to estimate last interglacial temperature change from the bottom part of the NEEM deep ice core. Published by Copernicus Publications on behalf of the European Geosciences Union. 1482 V. Masson-Delmotte et al.: Recent changes in northwest Greenland climate Figure 1. Map of Greenland showing the position of ice core records (red) and meteorological stations (green) used to establish a SW Greenland instrumental temperature record. The grey/white shading indicates elevation (source: NOAA/GLOBE, http://www. ngdc.noaa.gov/mgg/topo/globe.html).
(The Cryosphere. vol. 9, n° 1994-0424, pp. 1481-1504, 26/10/2026)
LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, GLACCIOS, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, NBI, UCPH, GEUS, ULiège, LGGE, OSUG, UJF, Grenoble INP, INSU - CNRS, IRSTEA, USMB [Université de Savoie] [Université de Chambéry], CNRS, INSU - CNRS, CNRS, ULR, ICMCB, UB, INC-CNRS, CNRS, LMD, UPMC, INSU - CNRS, X, IP Paris, ENPC, CNRS, ENS-PSL, PSL, AWI, INSTAAR
Increased aridity in southwestern Africa during the warmest periods of the last interglacial
Terrestrial and marine climatic tracers from marine core MD96-2098 were used to reconstruct glacial–interglacial climate variability in southwestern Africa between 194 and 24 thousand years before present. The pollen record documented three pronounced expansions of Nama-karoo and fine-leaved savanna during the last interglacial (Marine Isotopic Stage 5 – MIS 5). These Nama-karoo and fine-leaved savanna expansions were linked to increased aridity during the three warmest substadials of MIS 5. Enhanced aridity potentially resulted from a combination of reduced Benguela Upwelling, expanded subtropical high-pressure cells, and reduced austral-summer precipitation due to a northward shift of the Intertropical Convergence Zone. Decreased austral-winter precipitation was likely linked to a southern displacement of the westerlies. In contrast, during glacial isotopic stages MIS 6, 4 and 3, fynbos expanded at the expense of Nama-karoo and fine-leaved savanna indicating a relative increase in precipitation probably concentrated during the austral winter months. Our record also suggested that warm–cold or cold–warm transitions between isotopic stages and substages were punctuated by short increases in humidity. Increased aridity during MIS 5e, 5c and 5a warm substages coincided with minima in both precessional index and global ice volume. On the other hand, austral-winter precipitation increases were associated with precession maxima at the time of well-developed Northern Hemisphere ice caps.
(Climate of the Past. vol. 11, n° 1814-9324, pp. 1417-1431, 26/10/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Lab-scale experimental strategy for determining micropollutant partition coefficient and biodegradation constants in activated sludge
The nitrifying/denitrifying activated sludge process removes several micropollutants from wastewater by sorption onto sludge and/or biodegradation. The objective of this paper is to propose and evaluate a lab-scale experimental strategy for the determination of partition coefficient and biodegradation constant for micropollutant with an objective of modelling their removal. Four pharmaceutical compounds (ibuprofen, atenolol, diclofenac and fluoxetine) covering a wide hydrophobicity range (log Kow from 0.16 to 4.51) were chosen. Dissolved and particulate concentrations were monitored for 4 days, inside two reactors working under aerobic and anoxic conditions, and under different substrate feed conditions (biodegradable carbon and nitrogen). We determined the mechanisms responsible for the removal of the target compounds: (i) ibuprofen was biodegraded, mainly under aerobic conditions by cometabolism with biodegradable carbon, whereas anoxic conditions suppressed biodegradation; (ii) atenolol was biodegraded under both aerobic and anoxic conditions (with a higher biodegradation rate under aerobic conditions), and cometabolism with biodegradable carbon was the main mechanism; (iii) diclofenac and fluoxetine were removed by sorption only. Finally, the abilities of our strategy were evaluated by testing the suitability of the parameters for simulating effluent concentrations and removal efficiency at a full-scale plant.
(Environmental Science and Pollution Research. vol. 22, n° 0944-1344, pp. 4383-4395, 26/10/2026)
UR MALY, IRSTEA, UMR Qualisud, Cirad, UM1, UM2, Montpellier SupAgro, AU, UR, UM, Montpellier SupAgro, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Pression de sélection des barrages aquatiques sur la migration des civelles : approche moléculaire et comportementale
L’anguille européenne est une espèce amphihaline à migration catadrome facultative et à reproduction panmictique dans la mer de Sargasses. La dynamique de sa population est en fort déclin depuis les années 80. Parmi les facteurs qui ont pu contribuer à la disparition de l’espèce, on peut citer la pollution, la surpêche et la fragmentation de l’habitat. Ce dernier est intimement lié à la construction des barrages aquatiques. En effet, les rivières aménagées créent un obstacle au déplacement des anguilles dans les deux sens, c’est-à-dire lors de leur migration de croissance (en amont) ou de reproduction (en aval). Beaucoup d’efforts ont été faits afin d’augmenter la transparence de ces ouvrages. Par exemple, la migration en amont des jeunes stades d’anguilles est facilitée par la construction des passes à civelles, dont le design est adapté à leur taille et comportement. D’une manière générale, l’évaluation de l’impact des barrages, mais aussi de l’efficacité des passes à civelles est quantitative, où seule la proportion des poissons présents dans la parte amont du barrage/passe est comparée au nombre des poissons présents au pied du barrage ou s’engageant dans la passe. Malheureusement, la variabilité entre les individus pour les traits comme la capacité de nage ou d’escalade, la motivation, l’activité ou le comportement exploratoire est rarement prise en compte dans ce contexte. Cependant, certains traits pourraient faciliter le succès de passage par les obstacles, ce qui aboutirait à une sélection Afin d’évaluer si les barrages exercent une pression de sélection sur les civelles migrantes, une étude qualitative à été réalisée sur des groupes des civelles présentes d’une part et d’autre des obstacles. Tout d’abord, une approche par puce ADN a été adoptée pour identifier sans à priori les traits différant entre les groupes amont et aval. Ensuite, les tests expérimentaux ont été réalisés afin d’associer le phénotype moléculaire (expression des gènes) au phénotype organismique (comportement). Parmi les trois tissus étudiés ; le muscle, le foie et le cerveau, seul ce dernier a montré des différences significatives entre les groupes amont et aval des obstacles. Les gènes surexprimés des les parties amont des barrages sont impliqués dans la régulation de la plasticité synaptique et du développement neuronal, qui à son tour sont sollicités dans les processus de cognition, apprentissage et mémorisation. Le comportement d’escalade des parois verticales, souvent effectué en dehors de l’eau, est une condition à laquelle les civelles sont soumises pour la première fois de leur vie, ce qui peut suggérer que le processus d’apprentissage s’est mis en place à ce moment précis. Un tri comportemental effectué dans les conditions expérimentales confirme en partie l’association entre l’expression des gènes de plasticité synaptique et le comportement d’escalade individuel.
(pp. 1, 26/10/2026)
UR EABX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, EDF [E.D.F.]
Qu'est-ce qu'une eau de bonne qualité ?
Normes et définitions de la qualité de l'eau vis à vis des usages et limites.
(pp. 212-213, 26/10/2026)
UR ETBX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CNRS
Spatial and seasonal variations of methylmercury in European glass eels (Anguilla anguilla) in the Adour estuary (France) and relation to their migratory behaviour
Overall recruitment of European glass eels (Anguilla anguilla) has decreased significantly since the early 1980s. Due to their long life cycle, benthic/demersal habits and high lipid content, eels might accumulate high concentrations of contaminants, but data concerning glass eels are still scarce. This study provides original data on methylmercury (MeHg) concentrations in glass eels at spatial (marine and estuarine), annual and seasonal scales. The relationship between MeHg concentrations in glass eels and their propensity to migrate up estuaries was also investigated. MeHg data were individually related to the eels’ energetic condition which was estimated by dry weight. Glass eel migratory behaviour was investigated in an experimental flume and related to the MeHg concentration and dry weight at the individual scale. Marine and estuarine glass eels were caught from 2004 to 2011. There was a strong inverse correlation between MeHg concentrations and dry weight. MeHg concentrations increased in marine and estuarine glass eels from 2004 to 2009 and from 2004 to 2010, respectively, and then, both groups decreased in 2011. On a seasonal time scale, MeHg concentrations were higher at the end of the fishing season (April). MeHg bioaccumulation is likely to result from different sources, but the lack of significant differences between marine and estuarine glass eels suggests that direct contamination during estuarine migration is low. Other sources such as maternal transfer or oceanic contamination are discussed
(Environmental Science and Pollution Research. vol. 22, n° 0944-1344, pp. 10721-10732, 26/10/2026)
ECOBIOP, INRA, UPPA, IPREM, UPPA, INC-CNRS, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
The extreme mobility of debris avalanches: A new model of transport mechanism
Large rockslide-debris avalanches, resulting from flank collapses that shape volcanoes and mountains on Earth and other object of the solar system, are rapid and dangerous gravity-driven granular flows that travel abnormal distances. During the last 50 years, numerous physical models have been put forward to explain their extreme mobility. The principal models are based on fluidization, lubrication, or dynamic disintegration. However, these processes remain poorly constrained. To identify precisely the transport mechanisms during debris avalanches, we examined morphometric (fractal dimension and circularity), grain size, and exoscopic characteristics of the various types of particles (clasts and matrix) from volcanic debris avalanche deposits of La Réunion Island (Indian Ocean). From these data we demonstrate for the first time that syn-transport dynamic disintegration continuously operates with the increasing runout distance from the source down to a grinding limit of 500 μm. Below this limit, the particle size reduction exclusively results from their attrition by frictional interactions. Consequently, the exceptional mobility of debris avalanches may be explained by the combined effect of elastic energy release during the dynamic disintegration of the larger clasts and frictional reduction within the matrix due to interactions between the finer particles.
(Journal of Geophysical Research : Solid Earth. vol. 120, n° 2169-9313, pp. 8110–8119, 26/10/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LMV, UBP, INSU - CNRS, UJM, UJM EPE, CNRS, IRAMAT-CRP2A, IRAMAT, UTBM, UO, UBM, CNRS, LGSR, UR, IPG Paris