Novel ionization reagent for the measurement of gas-phase ammonia and amines using a stand-alone atmospheric pressure gas chromatography (APGC) source.

RationaleContaminants present in ambient air or in sampling lines can interfere with the target analysis through overlapping peaks or causing a high background. This study presents a positive outcome from the unexpected presence of N-methyl-2-pyrrolidone, released from a PALL HEPA filter, in the analysis of atmospherically relevant gas-phase amines using chemical ionization mass spectrometry.MethodsGas-phase measurements were performed using a triple quadrupole mass spectrometer equipped with a modified atmospheric pressure gas chromatography (APGC) source which allows sampling of the headspace above pure amine standards. Gas-phase N-methyl-2-pyrrolidone (NMP) emitted from a PALL HEPA filter located in the inlet stream served as the ionizing agent.ResultsThis study demonstrates that some alkylamines efficiently form a [NMP + amine+H]+ cluster with NMP upon chemical ionization at atmospheric pressure. The extent of cluster formation depends largely on the proton affinity of the amine compared with that of NMP. Aromatic amines (aniline, pyridine) and diamines (putrescine) were shown not to form cluster ions with NMP.ConclusionsThe use of NMP as an ionizing agent with stand-alone APGC provided high sensitivity for ammonia and the smaller amines. The main advantages, in addition to sensitivity, are direct sampling into the APGC source and avoiding uptake on sampling lines which can be a significant problem with ammonia and amines

Inadequate conflit of interest policies at most French teaching hospitals : a survey and web analysis

Background. There are 32 teaching hospitals in France, including 30 University hospitals and 2 Regional teachinghospitals. Teaching hospitals have three roles: health care provision, training of healthcare professionals, and medicalresearch. These roles lead to frequent interactions with pharmaceutical and medical device companies, inevitably raisingmajor risks of conflicts of interests. Therefore, policies to manage conflict of interests (COI) are crucial. This study aimsto examine COI policies in French teaching hospitals..Methods. All French teaching hospitals (n=32) were included in this study. All hospitals websites were screened forinstitutional COI policies and curriculum on COI, using standardized keyword searches. More data were collected througha questionnaire addressed to each chief executive officer (CEO) of the teaching hospital. We used predefined criteria (n=20) inspired by similar surveys on COI policies in French, US and Canadian medical schools, with some additions toreflect the local hospital context. A global score for each hospital, ranging from 0 to 58 (higher scores denoting strongerpolicies) was calculated by summing points obtained for each criterion.Results. Three out of 32 (9%) CEOs replied to the questionnaire. All 32 hospitals had websites; 16 hospitals listed policiesor regulations on their websites or provided them on request. In December 2017, among the 32 hospitals, we foundthat 17 (53.1%) had rules and regulations for some items only, 4 (12.5%) have considered implementing a policy, two ofwhich (6.3%) have begun implementation. and 15 (46.9%) had no evidence of COI policies and a null score. The maximumglobal score was 24 out of 58, with a mean of 3.50 ± 5.72.Conclusion. This is the first systematic assessment of COI policies in teaching hospitals in France. Such policies areneeded to protect patients, clinicians and students from undue commercial influence. Despite public and political pressurefor better management of COI since France’s benfluorex (Mediator) scandal of 2010, few teaching hospitals haveimplemented comprehensive and protective policies. We hope that periodic ranking of hospitals will contribute to raiseawareness of the importance of COI policy and speed introduction

Mise au point d un préleveur automatique pour la mesure en continu des composés carbonylés atmosphériques

En raison de leur implication dans les processus photochimiques responsables de la formation de l ozone troposphérique et de leur impact sur la santé humaine, les composés carbonylés font partis des composés organiques volatiles dont il est important de suivre en continu leur concentration atmophérique (fluctuation rapide de leur concentration dans l atmosphère). Ce présent travail de thèse répond à cette demande et deux stratégies de prélèvement ont été explorées dans l optique de disposer d un instrument automatique de mesure en continu des composés carbonylés atmosphériques. Dans un premier temps, le prélèvement par transfert de la phase gazeuse échantillonnée dans une phase liquide associé à une dérivation chimique des composés piégés a été étudié en raison de sa grande spécificité envers les composés carbonylés. Cependant aucun couple dispositif de prélèvement en phase liquide réactifs de dérivation ne permet un piégage quantitatif et/ou une utilisation en continu sur site. Une seconde stratégie, courrament employée dans le prélèvement des composés organiques volatiles (COV) a été étudiée : l adsorption à froid sur un support solide suivie d une thermodesorption couplée à une analyse directe par GC/MS. L efficacité de piégeage des composés carbonylés sur différents adsorbants solides s est révelée superieure à 95% pour les composés carbonylés composés de 1 (formaldéhyde, Pvap(-30C) = 34400 Pa) à 7 carbones (benzaldéhyde, Pvap(-30C) = 0,75 Pa). Fort de ces résultats, ce travail constitue une première étape fructueuse vers l élaboration d un instrument automatique pour la mesure en continu des composés carbonylés atmosphériques.Because of their implication in photochemical processes leadind to the formation of tropospheric ozone and their negative effect on human health, carbonyl compounds are part of the volatile organic compounds which demand a continuous measurement of their atmospheric concentration (fast fluctuation of their atmospheric concentration). The present research meets this requirement and two sampling strategies were studied to have an automatic instrument for the continuous measurement of atmospheric carbonyl compounds. First, sampling by using a tranfer of gaseous phase in a liquid phase associated with a simultaneous chemical derivatization of the trapped compounds was studied because of its high specificity towards carbonyl compounds. However, no couple sampling device-reagent allows a quantitative sampling of carbonyl compounds, nor a continuous measurement in the field. Another strategy was therefore studied: cryogenic adsorption onto solid adsorbent followed by thermodesorption and analysis by GC/MS. Collection efficiency using different solid adsorbents was greater than 95% for carbonyl compounds consisting of 1 (formaldehyde, Pvap (-30C) = 34400Pa) to 7 carbons (benzaldehyde, Pvap (-30C) = 0,75 Pa). This sampling strategy is a successful first step towards the realization of the automatic sampling device for a continuous measurement of atmospheric carbonyls compounds.AIX-MARSEILLE1-BU Sci.St Charles (130552104) / SudocSudocFranceF

New insights into secondary organic aerosol from the ozonolysis of α-pinene from combined infrared spectroscopy and mass spectrometry measurements.

Understanding mechanisms of formation, growth and physical properties of secondary organic aerosol (SOA) is central to predicting impacts on visibility, health and climate. It has been known for many decades that the oxidation of monoterpenes by ozone in the gas phase readily forms particles. However, the species responsible for the initial nucleation and the subsequent growth are not well established. Recent studies point to high molecular weight highly oxygenated products with extremely low vapor pressures (ELVOC, extremely low volatility organic compounds) as being responsible for the initial nucleation, with more volatile species contributing to particle growth. We report here the results of studies of SOA formed in the ozonolysis of α-pinene in air at 297 ± 2 K using atmospheric solids analysis probe (ASAP) mass spectrometry, attenuated total reflectance (ATR) Fourier transform infrared spectrometry and proton transfer reaction (PTR) mass spectrometry. Smaller particles are shown to be less volatile and have on average higher molecular mass components compared to larger particles, consistent with recent proposals regarding species responsible for the formation and growth of particles in this system. Thus the signatures of species responsible for particle development at various stages are observable even in particles of several hundred nm diameter. Pinonaldehyde and acetic acid were observed to evaporate from a film of impacted SOA at room temperature, from which the ratio of their diffusion coefficients to the square of the average film thickness, D/l(2), could be obtained. For acetic acid and pinonaldehyde, D/l(2) = 6.8 × 10(-6) s(-1) and 5.0 × 10(-6) s(-1) respectively, the relative magnitudes being consistent with the size difference between acetic acid and pinonaldehyde molecules. Limitations to quantifying the film thickness and hence absolute values of the diffusion coefficient are discussed and highlight a need for novel experimental methods for quantifying diffusion coefficients of organic species in SOA

Peroxides on the Surface of Organic Aerosol Particles Using Matrix-Assisted Ionization in Vacuum (MAIV) Mass Spectrometry.

Organic peroxides are key intermediates in the atmosphere but are challenging to detect, especially in the particle phase, due to their instability, which has led to substantial gaps in the understanding of their environmental effects. We demonstrate that matrix-assisted ionization in vacuum (MAIV) mass spectrometry (MS), which does not require an ionization source, enables in situ characterization of peroxides and other products in the surface layers of organic particles. Hydroxyl radical oxidation of glutaric acid particles yields hydroperoxides and organic peroxides, which were detected with signals of the same order of magnitude as the major, more stable products. Product identification is supported by MS/MS analysis, peroxide standards, and offline high-resolution MS. The peroxide signals relative to the stable carbonyl and alcohol products are significantly larger using MAIV compared to those in the offline bulk analysis. This is also the case for analysis using fast, online easy ambient sonic-spray ionization mass spectrometry. These studies demonstrate the advantage of MAIV for the real-time characterization of labile peroxides in the surface layers of solid particles. The presence of peroxides on the surface may be important for surface oxidation processes as well as for the toxicity of inhaled particles