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Pressurized intraperitoneal aerosol chemotherapy (PIPAC) is a technique to directly deliver chemotherapeutic drugs in the abdomen for the treatment of peritoneal metastases. Pressurization improves the treatment efficacy but increases the risk of exposure for the medical/non-medical staff who can be exposed by dermal or ocular contact, or inhalation of aerosols containing the cytotoxic drugs. The aim of this study was to evaluate the risk of exposure for the medical/non-medical staff (nurses, surgeons, anaesthesiologists and cleaning personnel; n = 13) during PIPAC with oxaliplatin performed according to the protocol recommended in France. Blood samples were collected 1 h before and immediately after PIPAC, and urine samples 1 h before, and then 3 h and the morning after PIPAC. In the control, non-exposed group (n = 7), only one urine and blood sample were collected. Surface contamination in the operating room was assessed in water- and Surfanios-impregnated wipe samples. The total elemental platinum in each sample was quantified by inductively coupled plasma mass spectrometry, using a method adapted to quantify trace amounts (ng.L−1) in very low volumes (100 μl). No surface contamination was detected. Although 25% of urine samples in the exposed group contained platinum, no statistical difference was observed in urine and plasma samples collected before and after PIPAC and with the control group samples. These findings suggest that the French PIPAC protocol does not increase the risk of exposure to platinum in all staff categories involved. This protocol could be considered in future occupational policies and consensus statements. Trial registration: NCT04014426

International audience; Asphaltenes are among the most challenging components in petroleum processing because they contain high amounts of heteroatoms (i.e., S, N, O, V, and Ni) thought to be responsible for strong aggregation tendencies, precipitation, and fouling problems. The role of vanadium- and nickel-containing petroleum compounds (i.e., petroporphyrins) in aggregation and fouling is not completely understood because asphaltene composition and structure is still a subject of debate in the petroleum chemistry community. Characterization of asphaltenes, namely, molecular analysis that employs no chromatographic separation, often fails to reveal their comprehensive composition. The work herein presents asphaltene fractionation by (1) solid/liquid extraction, which allows for separation of single-core (“island”) and multicore (“archipelago”) structural motifs and by (2) high-performance thin layer chromatography (HPTLC) with cellulose as the stationary phase and DCM/MeOH as the eluent, which facilitates access to petroporphyrins. Characterization is performed by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and matrix-assisted laser desorption ionization Fourier transform ion cyclotron resonance mass spectrometry (MALDI FT-ICR MS). The results demonstrate that even with multiple separation steps, a large quantity of vanadyl porphyrins remains inaccessible for molecular analysis by MALDI FT-ICR MS, which raises the question of what portion of a complex sample of asphaltene can be revealed by ultrahigh resolution mass spectrometry. Furthermore, the results show that easily accessible porphyrins migrate with the solvent front in HPTLC. Thus, HPTLC can be used to isolate and identify “free” porphyrins not locked into asphaltene aggregates; however, further development of separation methods is required to access the most difficult and problematic asphaltene fractions, which do not migrate and impose analytical challenges due to their stronger aggregation tendency.

International audience; Concentration of uranium (U), a naturally encountered radioactive element in earth’s crust, can be enhanced in freshwater ecosystems (µg.L-1 – mg.L-1) due to various anthropogenic activities. The consequent aquatic organism exposure to U leads to its accumulation in all organs, particularly in the gonad, and in subcellular fractions (mainly the cytosol); then it is known to affect fish at several biological levels, and more particularly, at a reproduction endpoint, with a decrease in the total number of eggs, spawn events and larvae survival. The understanding of U reprotoxicity requires the fine knowledge of its speciation at molecular level, i.e., its interaction with cytosolic biomolecules. In this study, we focus on the U-protein interactions in gonads. A non-denaturating extraction protocol combined with size exclusion chromatography (SEC) allowed the separation of metal-protein complexes in ovaries of U-contaminated wild roaches before their elemental detection (ICP MS). This enables unprecedented information to be obtained about U distribution in ovaries of autochthonous fish, Rutilus rutilus, which is different in some points from that obtained in the model species, Danio rerio under controlled laboratory conditions at a similar concentration level. Finally, the ability to transpose results from model to autochthonous fish was briefly discussed.

International audience; Understanding how essential and toxic elements are distributed in cereal grains is a key to improving the nutritional quality of cereal-based products. The main objective of this work was to characterize the distribution of Cd and of nutrients (notably Cu, Fe, Mn, P, S and Zn) in the durum wheat grain. Laser ablation inductively coupled mass spectrometry and synchrotron micro X-ray fluorescence were used for micro-scale mapping of Cd and nutrients. A dissection approach was used to quantitatively assess the distribution of Cd and nutrients among grain tissues. Micro X-ray absorption near-edge spectroscopy was used to identify the Cd chemical environment in the crease. Cadmium distribution was characterized by strong accumulation in the crease and by non-negligible dissemination in the endosperm. Inside the crease, Cd accumulated most in the pigment strand where it was mainly associated with sulfur ligands. High-resolution maps highlighted very specific accumulation areas of some nutrients in the germ, for instance Mo in the root cortex primordia and Cu in the scutellum. Cadmium loading into the grain appears to be highly restricted. In the grain, Cd co-localized with several nutrients, notably Mn and Zn, which challenges the idea of selectively removing Cd-enriched fractions by dedicated milling process.

International audience; Due to the dramatic quantity of plastic debris released into our environment, one of the biggest challenges of the next decades is to trace and quantify microplastics (MPs) in our environments, especially to better evaluate their capacity to transport other contaminants such as trace metals. In this study, trace elements (Fe, Cu, Zn, As, Cd, Sn, Sb, Pb, and U) were analyzed in the microplastic subsurface (200 μm) using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Microplastics subjected to the marine environment were collected on beaches (Guadeloupe) exposed to the north Atlantic gyre. We established a strategy to discriminate sorbed contaminants from additives based on the metal concentration profiles in MP subsurface using qualitative and quantitative approaches. A spatiotemporal correlation of the sorption pattern was proposed to compare MPs in terms of relative exposure time and time-weighted average concentrations in the exposure media.

A large fraction of the South-American cacao production is affected by new cadmium (Cd) regulations in cacao. This work was set up to characterize the distribution and speciation of Cd within the cacao fruit and to monitor potential Cd redistribution during cacao fermentation. In cacao fruits from four locations, Cd concentrations decreased with testa > nib ~ placenta ~ pod husk > mucilage. The distribution of Cd within cacao beans was successfully visualized using laser ablation inductively coupled plasma spectrometry (LA-ICP-MS) and confirmed higher Cd concentrations in the testa than in the nib. Speciation analysis by X-ray absorption spectroscopy (XANES) of unfermented cacao beans revealed that Cd was bound to O/N-ligands in both nib and testa. Fermentation induced an outward Cd migration from the nibs to the testa, i.e. against the total concentration gradient. This migration occurred only if the fermentation was sufficiently extensive to decrease the pH in the nib to

International audience; We studied the effects of supplementing a plant-ingredient based rainbow trout broodstock diet with different forms of selenium (Se) on reproductive performance, parental Se transfer and antioxidant metabolism in their progeny before first-feeding. Three groups of rainbow trout were fed a diet either without selenium supplementation (NC, basal Se level: 0.3 ppm) or supplemented with 0.3 ppm Se either in the form of sodium selenite (SS) or as hydroxy-selenomethionine (SO, dietary Se level: 0.7 ppm) over a 6-month period prior to spawning. In Se-supplemented groups, the total number of females spawning was significantly higher compared to the negative control group and the females fed SO began to spawn earlier compared to females fed SS or NC. Total Se concentrations were significantly higher in female muscle of SO group. Higher Se concentrations in the oocytes of both Se-supplemented groups confirmed a maternal transfer of Se, while total Se concentrations in milt samples were not significantly different between dietary groups. There was no effect on glutathione peroxidase (GPX) or other antioxidant enzyme activity in the liver of female or male broodstock, whereas in the swim-up fry, GPX activity was significantly higher in both Se-supplemented treatments with the highest activity in the SO group. Se-supplementation enhanced the expression of hepatic SelPa in broodstock males and females along with MsrB1, GPx1a, GPx4a2, CAT, Gclc, Keap1 and MsrB2 in male liver. In swim-up fry, only organic Se-supplementation led to a higher gene expression for SelPa, GPX1a, GPX1b2, CAT and MsrB2. An improvement of the oxidative status in whole-body of swim-up fry could not be confirmed in this study as the GSH/GSSG was even lower in swim-up fry of Se-supplemented groups, whereas the 8-isoprostane levels were lower in the SS group and no effect on protein carbonyl levels could be detected. Organic Se-supplementation led to a significant increase in the α-tocopherol and vitamin C levels in the progeny. These results show that dietary Se in broodstock nutrition influences spawning occurrence and along with the parental transfer, several traits in the progeny are affected.

International audience; In contrast to other trace elements that are cofactors of enzymes and removed from proteins under denaturing conditions, Se is covalently bound to proteins when incorporated into selenoproteins, since it is a component of selenocysteine aminoacid. It implies that selenoproteins can undergo several biochemical separation methods in stringent and chaotropic conditions and still maintain the presence of selenium in the primary sequence. This feature has been used to develop a method for the detection of trace levels of human selenoproteins in cell extracts without the use of radioactive isotopes. The selenoproteins are separated as a function of their isoelectric point (pI) using iso-electrofocusing (IEF) electrophoretic strips and detected by laser ablation-inductively coupled plasma mass spectrometry (LA-ICP MS). This method, therefore referred to as IEF-LA-ICP MS, allowed the detection of several selenoproteins in human cell lines, including Gpx1, Gpx4, TXNRD1, TXNRD2, and SELENOF.

International audience; Selenium (Se) is an essential component of genetically encoded selenoproteins, in the form of a rare amino acid, namely the selenocysteine (Sec). Radioactive (75)Se has been widely used to trace selenoproteins in vitro and in vivo (cell models and animals). Alternatively, its unique isotopic pattern can be used to detect and characterize nonradioactive Se-compounds in cellular extracts using molecular or elemental mass spectrometry at ppm levels. However, when studying trace levels of Se-compounds, such as selenoproteins (ppt levels), the distribution of the signal between its six naturally abundant isotopes reduces its sensitivity. Here, we describe the use of isotopically enriched forms of Se as an alternative strategy to radioactive (75)Se, for the labeling and tracing of selenoproteins in cultured cell lines.

New data on the nature of the protein targets of U within the zebrafish gills were collected after waterborne exposure to better understand uranium (U) toxicity mechanisms. This study evidenced some common characteristics of the U protein target binding properties such as their role in other essential metals regulation and their phosphorus content. In total 21 potential protein targets, including hemoglobin, were identified and discussed regarding the literature. This article is protected by copyright. All rights reserved

International audience; We characterized the biomolecules involved in handling cytosolic metals in larvae of the phantom midge (Chaoborus) collected from five mining-impacted lakes by determining the distribution of Ag, Cd, Cu, Ni, Tl, and Zn among pools of various molecular weights (HMW: high molecular weight, \textgreater670-40 kDa; MMW: medium molecular weight, 40-\textless1.3 kDa; LMW: low molecular weight, \textless1.3 kDa). Appreciable concentrations of nonessential metals were found in the potentially metal-sensitive HMW (Ag and Ni) and LMW (Tl) pools, whereas the MMW pool, which includes metallothioneins (MTs) and metallothionein-like proteins and peptides (MTLPs), appears to be involved in Ag and Cd detoxification. Higher-resolution fractionation of the heat-stable protein (HSP) fraction revealed further differences in the partitioning of nonessential metals (i.e., Ag = Cd ≠ Ni ≠ Tl). These results provide unprecedented details about the metal-handling strategies employed by a metal-tolerant, freshwater animal in a field situation. © 2016 American Chemical Society.

International audience; This text presents a novel method for the separation and detection of phosphorothioate oligonucleotides with the use of ion pair ultra high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry The research showed that hexafluoroisopropanol/triethylamine based mobile phases may be successfully used when liquid chromatography is coupled with such elemental detection. However, the concentration of both HFIP and TEA influences the final result. The lower concentration of HFIP, the lower the background in ICP-MS and the greater the sensitivity. The method applied for the analysis of serum samples was based on high resolution inductively coupled plasma mass spectrometry. Utilization of this method allows determination of fifty times lower quantity of phosphorothioate oligonucleotides than in the case of quadrupole mass analyzer. Monitoring of 31P may be used to quantify these compounds at the level of 80μgL-1, while simultaneous determination of sulfur is very useful for qualitative analysis. Moreover, the results presented in this paper demonstrate the practical applicability of coupling LC with ICP-MS in determining phosphorothioate oligonucleotides and their metabolites in serum within 7min with a very good sensitivity. The method was linear in the concentration range between 0.2 and 3mgL-1. The limit of detection was in the range of 0.07 and 0.13mgL-1. Accuracy varied with concentration, but was in the range of 3%. © 2014 Elsevier B.V.

International audience; Cadmium (Cd) is a potent selective toxicant that preferentially accumulates in the kidneys where it is known to induce cellular injury. The cellular mechanisms explaining toxicity have been well documented by in vivo and in vitro studies. However, experiments have mainly been performed on cadmium chloride (CdCl2), while several other forms, such as cadmium oxide (CdO) and cadmium sulfide (CdS), are of interest regarding occupational exposure. CdS is mainly used in nanotechnology, primarily to construct particles known as quantum dots (QDs). The present study focuses on cadmium forms that differ compared to their solubility and their particle size (CdS micro- and uncoated nanoparticles (NPs)), and investigates their effects on mesangial and proximal tubular kidney cells. Cellular toxicity was evaluated by using Neutral Red, MTT and WST-1 assays. Intracellular Cd content was measured using inductively coupled optical emission spectrometry (ICP-OES) and cellular stress was investigated via the effects of Cd complexing bioligands using size exclusion chromatography ICP-MS (SEC-ICP-MS). Data indicated the variability of cytotoxicity responses after CdCl2, CdO, and CdS exposure that were strongly correlated to the cellular Cd content. Release of Cd2+ linked to solubility and particle degradation were considered to be the cause of these toxicities. The bioinduction of the Cd-MT also evidenced release of Cd2+. Our in vitro data identified heterogeneity of Cd toxicity that was dependent on the physico-chemical properties of the form studied and, when considering particle size, constitute an additional step toward the determination of nanoparticle effects in renal cells.

International audience; A semi-quantitative method was developed for the non-targeted detection of trace levels of human selenoproteins in cytoplasmic cell extracts without the use of radioactive isotopes. The method was based on the direct detection of selenoproteins in iso-electrofocusing (IEF) electrophoretic strips by laser ablation-inductively coupled plasma mass spectrometry (LA-ICP MS). The proteins were identified in the non-ablated parts of the gel corresponding to the LA-ICP MS peak apexes by electrospray Orbitrap MS/MS. The method allowed a high resolution of the selenoproteins (peak width 0.06pH unit) using 3-10 pI strips. The protein detection limits were down to 1ngmL-1 (as Se). The method was applied to the selenoprotein speciation in different human cell lines: Hek293 (kidney), HepG2 (liver), HaCaT (skin) and LNCaP (prostate). The principal proteins found included Selenoprotein 15 (Sep15), Glutathione peroxidase 1 (GPx1) and Glutathione peroxidase 4 (GPx4) and Thioredoxin reductase 1 (TRxR1) and Thioredoxin reductase 2 (TRxR2). Biological significance: Our paper presents the development of a semi-quantitative method for the non-targeted detection of trace levels of human selenoproteins in cytoplasmic cell extracts; it offers a first comprehensive screening of the entire biological selenoproteomes expressed in cell lines without the use of radioactive 75Se. The method was based on the direct detection of selenoproteins in iso-electrofocusing (IEF) electrophoretic strips by laser ablation-inductively coupled plasma mass spectrometry (LA-ICP MS). The proteins were identified in the non-ablated parts of the gel corresponding to the LA-ICP MS peak apexes by electrospray Orbitrap MS/MS. The method allowed a high resolution of the selenoproteins (peak width 0.06pH unit) using 3-10 pI strips. The protein detection limits were down to 1ngmL-1 (as Se); by far the lowest ever reported. The method was applied to the selenoprotein speciation in different human cell lines: Hek293 (kidney), HepG2 (liver), HaCaT (skin) and LNCaP (prostate). The principal proteins found included Selenoprotein 15 (Sep15), Glutathione peroxidase 1 (GPx1) and Glutathione peroxidase 4 (GPx4) and Thioredoxin reductase 1 (TRxR1) and Thioredoxin reductase 2 (TRxR2). The IEF-LA-ICPMS indicates the presence of multiple forms of some selenoproteins which are for the moment impossible to distinguish because of the similarity of the bottom-up, proteomics data sets.

International audience; The follow-up of the Heated Intraoperative Chemotherapy (HIPEC) of peritoneal carcinomatosis would benefit from the monitoring of the penetration, distribution and metabolism of the drug within the tumor. As tumor nodules can be resected during the therapy, mass spectrometry imaging is a suitable tool for the evaluation of treatment efficacy, and, as a result, the therapy can be re-optimized. In this work we demonstrate the complementarity of laser ablation (LA) ICP mass spectrometry and MALDI imaging to study the penetration and distribution of two Pt-based metallodrugs (cisplatin and oxaliplatin) in human tumor samples removed from patients diagnosed with colorectal or ovarian peritoneal carcinomatosis. LA ICP MS offered sensitive (LOD for 195Pt 4.8 pg s-1) imaging of platinum quasi-independently of the original species and the sample matrix and thus an ultimate way of verifying the penetration of the Pt-containing drug or its moieties into the tumor. MALDI imaging was found to suffer in some cases from signal suppression by the matrix leading to false negatives. In the case of the oxaliplatin metallodrug, the results obtained from ICP and MALDI MS imaging were coherent whereas in the case of cisplatin, species detected by ICP MS imaging could not be validated by MALDI MS. The study is the first application of the dual ICP and MALDI MS imaging to the follow-up of metallodrugs in human tumors

International audience; The toxicity of uranium (U) to aquatic organisms depends notably on its compartmentalization in organs, tissues, cells as well as on its distribution among biomolecules. In order to contribute to the understanding of U accumulation and associated toxicity mechanisms in case of waterborne exposure, this study focused on U fate in the gills epithelia, uptake pathway, of the fish model Danio rerio (zebrafish). U distribution among cytosolic biomolecules was investigated after no addition (0μgL-1 (c0) for 3 and 30d), chronic (20μgL-1 (c20) for 30d) and acute (20μgL-1 (c20) and 250μgL-1 (c250) for 3d) exposures to depleted U. Cytosolic U accounted for an average of 24-32% of gills burden for c20 and c250, respectively. Size Exclusion Chromatography (SEC) coupled with Inductively Coupled Plasma-Sector Field Mass Spectrometry (ICP-SFMS) allowed identification of ecotoxicologically relevant U-containing fractions among cytosolic biomolecules as a function of exposure conditions. In c0 and c20 samples, most U (ca.80%) was found in the Low Molecular Weight fraction (LMW

cited By 20; International audience; A comprehensive approach to the characterization of metallothionein (MT) isoforms based on microbore HPLC with multimodal detection was developed. MTs were separated as Cd7 complexes, detected by ICP MS and tentatively identified by molecular mass measured with 1-2 ppm accuracy using Orbital ion trap mass spectrometry. The identification was validated by accurate mass of the corresponding apo-MTs after postcolumn acidification and by their sequences acquired online by higher-energy collision dissociation MS/MS. The detection limits down to 10 fmol and 45 fmol could be obtained by ESI MS for apo- and Cd7-isoforms, respectively, and were lower than those obtained by ICP MS (100 fmol). The individual MT isoforms could be sequenced at levels as low as 200 fmol with the sequence coverage exceeding 90%. The approach was successfully applied to the identification of MT isoforms induced in a pig kidney cell line (LLC-PK1) exposed to CdS nanoparticles. © 2010 American Chemical Society.

International audience; The potential of inductively-coupled plasma mass spectrometry (ICP-MS) and its complementarity to soft-ionization MS techniques are discussed in the context of the analysis for biomolecules. ICP-MS offers detection limits in the attomolar range, regardless of the molecular environment of the target element. The sensitivity is hardly affected by the sample matrix, chromatographic mobile phase, or co-eluted compounds. The abundance sensitivity over six decades and the linear dynamic range over nine decades make simultaneous multi-isotopic analysis routinely possible. The manuscript discusses the state-of-the-art of ICP-MS for the detection of proteins in gel electrophoresis and of peptides in 2D high-performance liquid chromatography. The possibilities of quantification to the degree of some post-translational modifications are highlighted. Attention is also paid to the role of ICP-MS in protein quantification via metal-coded labeling and to the use of differentially-labeled antibodies for the multiplexed biomarker analysis. The key role of ICP-MS in the emerging area of metallomics is briefly discussed. © IM Publications LLP 2010.

International audience; Concentrations of chromium, copper, iron, manganese and zinc were determined in liver, kidney, brain, lung, heart and testis of mouse following intraperitoneal injection of hexavalent chromium [Cr(vi)] at a single dose of 8.0 mg Cr/kg. As result, chromium concentrations increased ca. 40-fold in liver and kidney and by a factor of 3-5 in all the other tissues. The homeostasis of Cu, Fe, Mn and Zn was also affected. The element molecular weight distribution was evaluated in the cytosols of the different mouse organs by size-exclusion chromatography (Superdex-75) with UV-VIS and ICP-MS detection. The administration of Cr(vi) resulted in differences in the elution profiles of Fe, Mn, Cu and Zn-protein complexes. Bioinduced Mn, Fe and Zn-binding proteins could be detected in some tissues, especially in liver and kidney. Different molecular weight fractions containing chromium were heartcut and submitted to tryptic digestion prior to MALDI MS analysis. Cr-peptide complexes could be obtained both in non-denaturing and in denaturing (in the presence of urea and DTT) conditions. They were isolated by size-exclusion chromatography with a smaller separation range (Superdex Peptide) but could not be identified by MALDI MS. © The Royal Society of Chemistry 2010.

Uranium is a naturally abundant element which has been used in several industries. Internal exposure could occur via three main pathways that are ingestion, inhalation and wounds. It has been recently shown that chronic ingestion of uranium in drinking water induces an important uranium accumulation in kidney with a perturbation of iron metabolism in this organ. Whereas uranium speciation is a key parameter to elucidate the chemical reactivity and the mobility of an element, it remains poorly documented in most of environmental and biological media. A few examples of uranium complexation with biomolecules have been published recently but most of them are in vitro studies whereas in vivo experiments remain poorly investigated. In order to better understand possible competition of uranium towards metals involved in the metal-protein binding, i.e. iron, copper, calcium, a study on uranium speciation was investigated by doing an in vivo screening of target proteins likely to bind it in kidneys of exposed rats. Rats were chronically exposed via contaminated drinking water at 40 mg L-1 and killed 9 months after the beginning of exposure. Kidneys were dissected out and protein extract was prepared. Then, separation of renal proteins by isoelectric focusing gel electrophoresis (IEF) and two-dimensional gel electrophoresis (2-DE) followed by LA-ICPMS analysis were performed. IEF-LA-ICP MS showed that uranium could specifically bind few proteins in kidney whereas 2-DE-LA-ICP MS could indicate that uranium is not covalently bound to proteins in this organ. The results suggested that even at moderate concentrations of exposure, uranium can be observed chelated with some renal proteins that is very encouraging to understand the entry, storage and elimination of this element in kidneys.

International audience; A 2D high repetition rate femtosecond laser ablation strategy (2-mm wide lane) previously developed for the detection of selenoproteins in gel electrophoresis by inductively coupled plasma mass spectrometry was found to increase signal sensitivity by a factor of 40 compared to conventional nanosecond ablation (0.12-mm wide lane) [G. Ballihaut, F. Claverie, C. Pécheyran, S. Mounicou, R. Grimaud and R. Lobinski, Sensitive Detection of Selenoproteins in Gel Electrophoresis by High Repetition Rate Femtosecond Laser Ablation-Inductively Coupled Plasma Mass Spectrometry, Anal. Chem. 79 (2007) 6874-6880]. Such improvement couldn't be explained solely by the difference of amount of material ablated, and then, was attributed to the aerosol properties. In order to validate this hypothesis, the characterization of the aerosol produced by nanosecond and high repetition rate femtosecond laser ablation of polyacrylamide gels was investigated. Our 2D high repetition rate femtosecond laser ablation strategy of 2-mm wide lane was found to produce aerosols of similar particle size distribution compared to nanosecond laser ablation of 0.12-mm wide lane, with 38% mass of particles \textless 1 μm. However, at high repetition rate, when the ablated surface was reduced, the particle size distribution was shifted toward thinner particle diameter (up to 77% for a 0.12-mm wide lane at 285 μm depth). Meanwhile, scanning electron microscopy was employed to visualize the morphology of the aerosol. In the case of larger ablation, the fine particles ejected from the sample were found to form agglomerates due to higher ablation rate and then higher collision probability. Additionally, investigations of the plasma temperature changes during the ablation demonstrated that the introduction of such amount of polyacrylamide gel particles had very limited impact on the ICP source (ΔT~ 25 ± 5 K). This suggests that the cohesion forces between the thin particles composing these large aggregates were weak enough to have negligible impact on the ICPMS detection. © 2009 Elsevier B.V. All rights reserved.

International audience; It has been suggested that copper-zinc superoxide dismutase (CuZnSOD) isoforms of distinct isoelectric point (pI) could result from differences in their metallation state. Our aim was then to develop and validate analytical methods for the determination and understanding of metallation states in human CuZnSOD isoforms. To avoid metal losses during sample preparation steps, CuZnSOD isoforms were separated according to their pI using non-denaturing isoelectric focusing (IEF) gel electrophoresis. Metal quantification was directly performed in-gel. Cu/Zn ratios of CuZnSOD isoforms were quantified by Particle-Induced X-ray Emission (PIXE) and Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS). Cu/Zn ratios were measured close to the value of 1 as expected from the known stoichiometry of CuZnSOD with slight, but statistically significant, differences between acidic and basic isoforms. Overall, this study demonstrates that metal quantification can be performed directly on metalloproteins separated on electrophoresis gels. © 2009 Elsevier Masson SAS. All rights reserved.

International audience; The emerging field of metallomics refers to the entirety of research activities aimed at the understanding of the molecular mechanisms of metal-dependent life processes. This critical review discusses the concept of metallomics with a focus on analytical techniques and methods for the probing of interactions between metal ions and the organism's genome and the derived -omes: proteome and metabolome. Particular attention is paid to the in vivo screening for the native metal-protein and metal-metabolite complexes by hyphenated techniques that combine a high-resolution separation technique (gel electrophoresis, chromatography or capillary electrophoresis) with sensitive elemental (inductively coupled plasma, ICP) or molecular (electrospray or MALDI) mass spectrometric detection. The contribution of bioinformatics to the prediction of metal-binding sequences in proteins and the role of molecular biology approaches for the detection of metal-dependent genes, proteins and metabolites are highlighted (115 references). © The Royal Society of Chemistry 2009.

Metal ions play a fundamental role in the chemistry of life. The understanding of the molecular bases of the living process requires the knowledge of the correlations existing between metal ions and the genome and the derived -omes: transcriptome, proteome, and metabolome. An indispensable step on this way is the characterization of the coordination environment of metal ions present and the identification and quantification of metal-containing chemical species. The ensemble of research activities related to metal ions in biological systems has been recently referred to as "metallomics" [1]. The progress in this field is largely dependent on the high-throughput acquisition of multielement and -species analytical data in biological samples. The paper gives a brief overview of the state of the art of analytical techniques and methods for the multielement quantitative analysis of biological microsamples, and for the detection, identification, and quantitation of metal-containing proteins and low-molecular-weight metabolites. The potential contribution of molecular biology techniques in terms of linking information on metals and metal-species to the genome of an organism is highlighted.

cited By 34; International audience; Speciation of heteroelement-containing proteins essential for human health is one of the most rapidly developing areas in bio-inorganic analytical chemistry (metallomics). We discuss recent advances in mass spectrometry (MS) techniques for detection and identification of selenium (Se)-containing proteins separated by gel electrophoresis (GE). These advances include location of Se-containing bands in 1D GE or spots in 2D GE by laser-ablation inductively coupled plasma MS (LA-ICP-MS) followed by protein identification by matrix-assisted laser-desorption/ionization MS (MALDI-MS) and nano-high-performance liquid chromatography-electrospray-tandem MS (nanoHPLC-ESI-MS2). We highlight the differences with the classical proteomics approach resulting from the presence of the Se atom. © 2007 Elsevier Ltd. All rights reserved.

International audience; A laser ablation-ICPMS method using an infrared (1030 nm), low-energy (39 ?J/pulse), high repetition rate (10 kHz), femtosecond laser was developed to improve the sensitivity of detection of heteroatom-containing proteins in 1D polyacrylamide gels. A 2-mm-wide lane was ablated by ultrafast (10 cm s -1) back-and-forth movement of a 20-?m laser beam parallel to the protein bands while the gel advanced perpendicularly. This procedure resulted in a considerable increase in detection sensitivity (> 40-fold) compared to the nanosecond 266-nm laser ablation-ICPMS, mainly because of the much larger amount of ablated material introduced into the plasma on the time scale of the dwell time of the mass spectrometer. The method was applied to the specific detection in the gel of formate dehydrogenase expressed in Escherichia coli and of selenoproteins in Desulfococcus multivorans with detection limits at the low-femtomolar levels. © 2007 American Chemical Society.

International audience; Concentrations and bioavailability of cadmium (Cd) and lead (Pb) were determined in cocoa powders and related products (beans, liquor, butter) of different geographical origins. Particular attention was paid to the fractionation of these metals, which was investigated by determining the metal fraction soluble in extractant solutions acting selectively with regard to the different classes of ligands. The targeted classes of Cd and Pb species included: water-soluble compounds, polypeptide and polysaccharide complexes, and compounds soluble in simulated gastrointestinal conditions. The bioavailability of Cd and Pb from cocoa powder, liquor and butter was evaluated using a sequential enzymolysis approach. The data obtained as a function of the geographical origin of the samples indicated strong differences not only in terms of the total Cd and Pb concentrations, but also with regard to the bioavailability of these metals. The Cd concentrations in the cocoa powders varied from 94 to 1833 g kg-1, of which 10-50% was potentially bioavailable. The bioavailability of Pb was generally below 10% and the concentrations measured in the cocoa powders were in the 11-769 ?g kg-1 range. Virtually all the Cd and most of Pb were found in the cocoa powder after the pressing of the liquor.

International audience; A two-dimensional separation approach based on size-exclusion chromatography (SEC) followed by capillary zone electrophoresis (CZE) is proposed for the mapping of seleno-compounds in aqueous extracts of selenized yeast. The coupling of CZE with ICP-MS via a self-aspirating total consumption micronebulizer was optimized for the separation of Se species. Selenate, selenite, selenocystine, selenomethionine and selenoethionine could be baseline separated at pH 10.5 using a 10 mM phosphate buffer containing 0.8 mM cetyltriammonium bromide. Detection limits were 7-18 ng mL-1 for a 20 nL injection. The CZE-ICP-MS analysis of a yeast extract demonstrated the presence of many Se species, which all migrated less rapidly than any of the standards. The following difficulties occurred during the CZE-ICP-MS analysis of the SEC fractions of the extract: the recovery of the high-molecular Se-species from the electrophoretic capillary, the presence of a large number of compounds in the medium-molecular weight fraction and the presence of a single intense peak for the low-molecular weight fraction. Proteolysis of the high- and medium-molecular weight fractions dramatically improved the recovery of Se species from the capillary, resulting in several peaks in the CZE-ICP-MS electropherograms.

International audience; The complementarity of CZE-ICP-MS and CZE-ES-MS couplings was evaluated for the characterization of metal complexes with metallothionein (MT) isoforms. The preparations characterized included the rabbit liver MT and its further purified MT-1 and MT-2 isoforms. The CZE-ICP-MS electrophoregrams showed the presence of several well (often baseline) separated Gaussian-shape peaks. ES-MS was used for the identification of these signals; mass spectra taken at the peak apexes were complex and indicated the co-existence of several metal complexes (possibly with different isoforms) within each peak. Many of these complexes could be identified on the basis of the molecular mass. The study highlights the attractive potential of CZE-ICP-MS and CZE-ES-MS when used in parallel for the characterization of metal complexes with biomolecular ligands. The inherent discrepancy between the sensitivities of ICP-MS and ES-MS is partly alleviated by the fact that the metal (detected by ICP-MS) constitutes only a small fraction of the total molecule (detected by ES-MS), and by the smaller dilution factor with the makeup sheath flow in ES-MS than in ICP-MS.

International audience; Recent advances in the coupling of gas chromatography (GC) and high performance liquid chromatography (HPLC) with inductively coupled plasma mass spectrometry (ICP MS) and their role in trace element speciation analysis of environmental materials are presented. The discussion is illustrated with three research examples concerning the following topics: (i) development and coupling of multicapillary microcolumn GC with ICP MS for speciation of organotin in sediment and biological tissue samples; (ii) speciation of arsenic in marine algae by size-exclusion-anion-exchange HPLC-ICP MS; and (iii) speciation of cadmium in plant cell cultures by size-exclusion HPLC-ICP MS. Particular attention is paid to the problem of signal identification in ICP MS chromatograms; the potential of electrospray MS/MS for this purpose is highlighted.

International audience; A glass rod (5-20 cm long, 2 mm o.d.) containing more than 1200 parallel microchannels ( 100 theoretical plates cm-1) GC column by coating the inside of each channel in a way that compensated for the dispersion of the channel inner diameter. The columns were evaluated for the separation of mixtures of several organometallic (Hg, Sn, Pb) compounds prior to on-line sensitive metal- selective detection by ICPMS. Chromatographic separation conditions were optimized to enable a rapid (within a maximum 30 s) multielemental speciation analysis. Absolute detection limits were 0.1 pg for Hg, 0.05 pg for Sn, and 0.03 pg for Pb using the carrier gas flows of ~200 mL min-1. The microcolumn multicapillary GC/ICPMS developed was applied to the analysis of a number of environmental samples. The results were validated with certified reference materials for fin (BCR477, PACS-2) and mercury (DORM-1, TORT-1).