[en] • The work described here relies on organic compounds used in the nuclear cycle (extractants, diluents and specific additives) to provide a valuable information about the origin and process of nuclear materials. • When used in headspace mode, MONOTRAP is an efficient method to capture trace-level volatile and semi-volatile organic markers from small amounts (10 – 100 mg) of uranium ore concentrates (UOCs). • MONOTRAP is easy to implement in the field for control of nuclear material in the context of nuclear safeguards, without any contact with the radioactive samples, avoiding radiological contamination controls. • When combined with the high-resolution power and mass accuracy of a GC/Q-TOF mass analyzer, using both electron impact and chemical ionization and a comprehensive search against our “in-house” spectral database of “non-proliferation” organic chemical markers: this new method has the potential to facilitate the identification of nuclear production processes and thus to verify the correctness and the completeness of the declarations made by the States about their nuclear material and activities. (author)

[en] Highlights: • Theory and modeling of organophosphorus SBSE extraction are presented. • Organophosphorus are quantitatively analyzed by isotopic dilution SBSE/DART/Orbitrap-MS. • PDMS coated Twisters™ extract phosphate acid esters in the neutral form from water samples. • Good linearity between concentrations and relative peak areas (0.1–750 ng mL"−"1). • This novel SBSE/DART/Orbitrap-MS method should be very valuable for on-site sampling/monitoring - Abstract: A novel hyphenated technique, namely the combination of stir bar sorptive extraction (SBSE) with isotope dilution direct analysis in real time (DART) Orbitrap™ mass spectrometry (OT-MS) is presented for the extraction of phosphoric acid alkyl esters (tri- (TnBP), di- (HDBP), and mono-butyl phosphate (H2MBP)) from aqueous samples. First, SBSE of phosphate esters was performed using a Twister™ coated with 24 μL of polydimethylsiloxane (PDMS) as the extracting phase. SBSE was optimized for extraction pH, phase ratio (PDMS volume/aqueous phase volume), stirring speed, extraction time and temperature. Then, coupling of SBSE to DART/Orbitrap-MS was achieved by placing the Twister™ in the middle of an open-ended glass tube between the DART and the Orbitrap™. The DART mass spectrometric response of phosphate esters was probed using commercially available and synthesized alkyl phosphate ester standards. The positive ion full scan spectra of alkyl phosphate triesters (TnBP) was characterized by the product of self-protonation [M + H]"+ and, during collision-induced dissociation (CID), the major fragmentation ions corresponded to consecutive loss of alkyl chains. Negative ionization gave abundant [M − H]"− ions for both HDnBP and H2MnBP. Twisters™ coated with PDMS successfully extracted phosphate acid esters (tri-, di- and mono-esters) granted that the analytes are present in the aqueous solution in the neutral form. SBSE/DART/Orbitrap-MS results show a good linearity between the concentrations and relative peak areas for the analytes in the concentration range studied (0.1–750 ng mL"−"1). Reproducibility of this SBSE/DART/Orbitrap-MS method was evaluated in terms of %RSD by extracting a sample of water fortified with the analytes. The %RSDs for TnBP, HDnBP and H_2MnBP were 4, 3 and 3% (n = 5) using the respective perdeuterated internal standards. Matrix effects were investigated by matrix matched calibration standards using underground water samples (UWS) and river water samples (RWS). Matrix effects were effectively compensated by the addition of the perdeuterated internal standards. The application of this new SBSE/DART/Orbitrap-MS method should be very valuable for on-site sampling/monitoring, limiting the transport of large volumes of water samples from the sampling site to the laboratory