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International audience; The speciation analysis of complex mixtures of chemicals requires an efficient separation method and supercritical fluid chromatography (SFC) is one such technique that has been used for these purposes. Hyphenation of SFC to inductively coupled plasma mass spectrometry (ICP-MS) can provide elemental speciation information. However, the hyphenation of modern SFC instrumentation to ICP-MS has not yet been tested. The aim of this study was to develop a novel interface to hyphenate ICP-MS and modern HPLC-like SFC systems that enable the use of organic solvent gradients and packed columns. For this, an optimization of the most important parameters, such as SFC back pressure, gas temperature and position of the interface within the whole set up, was carried out, and quantitative analyses in flow injection analysis (FIA) mode of two biolubricants and one pyrolysis oil were accomplished, reaching DLs at the ppb level with the tested mobile phase compositions. In addition, in order to test the performance of this novel interface with real samples, chromatographic separation experiments of one pyrolysis oil and one coal tar using a 2-picolylamine column were carried out, confirming the stability of this new interface and its potential to become a powerful speciation technique in the future.

Renewable feedstocks, such as lignocelulosic fast pyrolysis oils and both vegetable oil and animal fats, are becoming a viable alternative to petroleum for producing high-quality renewable transportation fuels. However, the presence of phosphorus-containing compounds, mainly from phospholipids, in these renewable feedstocks is known to poison and deactivate hydrotreating catalysts during fuel production. In this work, gel permeation chromatography (GPC) combined with inductively coupled plasma high-resolution mass spectrometry (ICP-HRMS) was used to analyze feedstocks including unprocessed soybean oil, animal fat, and pyrolysis oils from red oak and milorganite to identify phosphorus species. The results have shown the presence of a wide range of different phosphorous compounds among all the samples analysed in this work. The GPC-ICP-HRMS analyses of a vegetable oil and two animal fats have shown different fingerprints based on the molecular weight of each of the samples, highlighting the structural differences among their corresponding phosphorus-containing compounds. While the presence of low-molecular-weight species, such as phospholipids, was expected, several high-molecular-weight species (MW10 000 Da) have been found, suggesting that high-molecular-weight micelles or liposomes might have been formed due to the high concentration of phospholipids in these samples. Results obtained through the hydroxylation of a mix of phospholipids (asolectin) and its posterior GPC-ICP-HRMS agree with this hypothesis. With respect to the lignocellulosic catalytic fast pyrolysis oil samples, the GPC-ICP-HRMS results obtained suggest that either aggregation or polymerization reactions might have occurred during the pyrolysis process, yielding phosphorus-containing compounds with an approximate molecular weight above 91 000 kDa. In addition, an aggregation phenomenom has been observed for those phosphorus species present within the fast pyrolysis oils after being stored for 3 months, especially for those pyrolysis oils contaning pre-processed feedstocks, such as milorganite.

International audience; Processes based on homogeneous catalysts are the most widely used for industrial production of fatty acid derivatives, despite catalyst loss in aqueous effluents during the wet-purification stage. In this work, dry-purification of the crude bioproducts; ethyl biodiesel and biolubricants, derived from Indian mustard was conducted using various natural mineral (clay) and organic (plant issue) adsorbents to evaluate operating conditions including temperature, contact time and number of treatment cycles and to define the optimal procedure. Adsorbent characterization was determined by average particle size assessed using laser granulometry, morphology and elemental chemical composition measured by scanning electron spectroscopy with microanalysis using energy dispersive X-ray spectroscopy, chemical structure determination based on Fourier Transform InfraRed spectroscopy and porosity and specific area assessed using carbon dioxide or nitrogen adsorption. The quality of the biofuel and biolubricants, before and after dry-purification on the above adsorbents, was evaluated using different methods including Karl Fischer titration, gas chromatography with a flame ionization detector and inductively coupled plasma-atomic emission spectroscopy. Montmorillonite clay and finely ground Indian mustard stems (particle size of 100–710 μm) without further pyrolysis or carbonization treatment were found to be the best adsorbents. Combined with the selected dry-purification procedure (35–45 °C, 20 min, single treatment cycle), most impurities including residual glycerides, free glycerin, water, catalysts and metals were removed from the resultant ethyl biodiesel thus meeting the basic biofuel specifications of acid value, color, density, viscosity, flash point, pour point, cloud point, cold filter plugging point, higher heating value, and oxidation stability. Further purification of biolubricants was required using bubble-washing with citric acid and vacuum distillation to obtain a product with acceptable density, viscosity and color. This work highlights the potential of a biorefinery system focused on Indian mustard contributing to a green circular economy, that would benefit both farmers and consumers in the respect of environment; farmers would gain in energy security and flexibility by biofuel, biolubricant and other bioproducts on-farm production, while ensuring healthy food security and offering job opportunities, the whole with reduced chemical and energy inputs and minimized waste effluents.

International audience; A new total consumption micronebuliser for ICP-MS was developed and optimised in this work. This nebuliser, V64-01, which was built through 3D printing, contains a larger internal diameter than other total consumption micronebulisers, a silicon-free capillary that perfectly tolerates a flow up to 65 μL min-1 THF, and the chances of incurring obstructions or clogging during a prolonged period of analysis are reduced. In addition, its production costs are minimal. To validate this nebuliser, its most important parameters were optimised (carrier gas and liquid flow rates), and the quantitative analysis of an SRM sample was carried out successfully. Calibration curves with great linearities (r2 > 0.999) and detection limits between 0.84 and 2.85 ng g-1 were obtained for the analysis of 10 elements. In addition, GPC-ICP-MS chromatograms of the size distribution of V and Ni species in a reference crude oil sample were obtained, showing the same profile as with the previous nebulisers but also suggesting that, for some species of V and Ni in crude oil, permanent retention might have occurred within the fused silica capillary that connects the DS-5 total consumption micronebuliser with the HPLC system. This new 3D-printed total consumption nebuliser possesses the potential to become a good consumable that will allow for total and speciation analysis of numerous trace elements, such as Si, that, until now, due to either interactions with silica or interferences, were not possible to analyse.

International audience; This study describes the use of gel permeation chromatography inductively coupled plasma high-resolution mass spectrometry (GPC ICP HRMS) to examine and explain two important petroleum industry catalytic processes: hydrodemetallization (HDM) and hydrodesulfurization (HDS). The sulfur, nickel and vanadium species size distributions in atmospheric residue fractions were studied to track their evolution during both catalytic processes and examine their mechanisms, especially those mechanisms linked to changes in temperature and initial deactivation via coke laydown. Chromatogram shapes as well as peak areas were used to study the V, Ni and S aggregate types and concentrations in the feedstock as well as in the product after varying the operating temperature and residence time at a constant temperature. For the V and Ni compounds, the low and medium molecular weight (LMW and MMW, respectively) aggregates are easily hydrotreated under all conditions, while the high molecular weight (HMW) compounds are more refractory. For the S compounds, a different reactivity pattern was observed whereby the LMW, MMW and HMW aggregates were more similar in their reactivity, showing that the catalyst is less selective towards a certain aggregate size for the S compounds compared to the V or Ni compounds.

International audience; A method using liquid–liquid extractions has been developed for matrix simplification and evaluated by gel permeation chromatography coupled with inductively coupled plasma and mass spectrometry. In this method, maltenes were dissolved in n-heptane and extractions with methanol (MeOH), acetonitrile (ACN), and dimethylformamide (DMF) were performed. The extraction with ACN is more efficient than that with MeOH for the removal of compounds with low-molecular weights (LMW) containing V (our reference element) and more selective than that with DMF (with this solvent, compounds with LMW and medium-molecular weights (MMW) are extracted). Thus, a sequential extraction was performed by applying ACN to selectively remove LMW compounds, followed by extractions with DMF of the resulting maltene to separate the MMW compounds from the high-molecular weights (HMW) compounds remaining in the final remnant maltene. The results show, for the first time in the literature, that it is possible to separate the three V and Ni species of compounds present in maltenes based on their molecular weights (HMW, MMW, and LMW).