Chemical characterization of volatile organic compounds emitted by animal manure.

Animal manure is considered a valuable organic fertilizer due to its important nutrient content enhancing soil fertility and plant growth in agriculture. Besides its beneficial role as fertilizer, animal manure represents a significant source of volatile organic compounds (VOCs), playing a significant role in atmospheric chemistry. Understanding the composition of VOCs Understanding VOCs from animal manure is crucial for assessing their environmental impact, as they can cause air pollution, odors, and harm to human health and ecosystems. Laboratory studies enhance field measurements by providing a precise inventory of manure emissions, addressing gaps in existing literature. Both approaches complement each other in advancing our understanding of manure emissions. In this context, we conducted an experimental study involving various animal manures (cow, horse, sheep, and goat) taken from a farm in Grignon (near Paris, France). We employed atmospheric simulation chambers within a controlled laboratory environment. The analysis of VOCs involved the combination of Proton Transfer Reaction-Quadrupole ion guide-Time-of-Flight Mass Spectrometry (PTR-QiTOF-MS) and Thermal Desorption-Gas Chromatography-Mass Spectrometry (TD-GC-MS). Using PTR-QiTOF-MS, 368 compounds were detected and quantified within the manure samples. The complementary analysis by TD-GC-MS enhanced our identification of VOCs. Our findings revealed various chemical groups of VOCs, including oxygenated compounds (e.g., ethanol, cresol, acetaldehyde, etc.), nitrogenated compounds (ammonia, trimethylamine, etc.), sulfur compounds (methanethiol, dimethyl sulfide, etc.), aromatic compounds (phenols and indoles), terpenes (isoprene, D-limonene, etc.) and halogenated compounds. Cow manure exhibited the highest VOC emission fluxes, followed by goat, sheep, and horse manures. Notably, oxygenated VOCs were dominant contributors to total VOC emission fluxes in all samples. Statistical analysis highlighted the distinct nature of cow manure emissions, characterized by oxygenated compounds and nitrogenated compounds. In addition, goat manure was isolated from the other samples with high emissions of compounds having both oxygen and nitrogen atoms in their molecular formulas (e.g., CH3NO2). The experimental dataset obtained in this study provides an inventory reference for both VOCs and their emission fluxes in animal manures. Furthermore, it highlights odorant compounds and VOCs that serve as atmospheric aerosol precursor. Future studies can explore the effectiveness of various manure treatment methods to promote sustainable agriculture practices.

Chemical identification and quantification of volatile organic compounds emitted by sewage sludge.

The recycling of organic waste products (e.g. sewage sludge, SS) is currently being promoted as a substitute for mineral fertilizers for agricultural lands. The spreading of SS allows the recycling of the nutrients and organic matter it contains. SS contains various pollutants such as volatile organic compounds (VOCs) that adversely affect the ecosystem and human health through ozone production and serve as critical precursors of atmospheric secondary organic aerosols. There are very few studies quantifying the gaseous compounds emitted from SS, and those studies primarily address their odorant properties for identifying suitable odour abatement techniques. There is an urgent need for more comprehensive quantitative information on VOCs emitted from SS as aerosol precursors. In this context, an experimental study was performed on SS samples taken from a wastewater treatment plant located in France. Undigested SS (UDSS), digested SS (DSS) and SS with 30% and 60% dryness were collected from different stages of treatment sequence and analyzed using atmospheric simulation chambers coupled to proton-transfer-reaction quadrupole ion-guide time-of-flight mass spectrometer. Our study revealed that SS samples emitted a large spectrum of VOCs. 380 compounds were detected, quantified and classified into different chemical groups. The VOC emissions increased with the increase in the dryness of the sample; the highest being in SS 60%, followed by SS 30%, UDSS and DSS. OVOCs were dominant in SS 60%. The statistical analysis showed that the anaerobic digestion and the dewatering to 60% of dryness decreased the emissions of sulphuric compounds. Aromatic compounds and indoles (e.g. skatole) were emitted significantly from the UDSS. Some of these VOCs can serve as precursor gases for atmospheric aerosol formation. The experimental dataset obtained in this study provides an accurate inventory reference for the VOC emissions from SS samples and shows the impacts of the treatment on emission characteristics of VOCs.

On the benefits of using multivariate analysis in mass spectrometric studies of combustion-generated aerosols.

The intricate chemistry of the carbonaceous particle surface layer (which drives their reactivity, environmental and health impacts) results in complex mass spectra. In this respect, detailed molecular-level analysis of combustion emissions may be challenging even with high-resolution mass spectrometry. Building on a recently proposed comprehensive methodology (encompassing all stages from sampling to data reduction), we propose herein a comparative analysis of soot particles produced by three different sources: a miniCAST standard generator, a laboratory diffusion flame and a single cylinder internal combustion engine. The surface composition is probed by either laser or secondary ion mass spectrometry. Two examples of multivariate analysis, Principal component analysis and hierarchical clustering analysis proved their efficiency in both identifying general trends and evidencing subtle differences that otherwise would remain unnoticed in the plethora of data generated during mass spectrometric analyses. Chemical information extracted from these multivariate statistical procedures contributes to a better understanding of fundamental combustion processes and also opens to practical applications such as the tracing of engine emissions.

Real time and in vivo pharmaceutical and environmental studies with SpiderMass instrument.

Remote Infrared Matrix Assisted Laser Desorption Ionization (Remote IR MALDI) system (SpiderMass) with endogenous water as matrix allows to perform real-time DMPK in vivo. In this work, SpiderMass was used to analyze the impact on metabolite production or release of invalidated pro-protein PC1/3 macrophages by Short RNA (shRNA) versus scramble shRNA with Paclitaxel. Time course in vivo experiments were then performed on the inner and outer faces of patients' forearms or comedo treated with Melascreen (Ducray) containing ascorbyl glucoside. Finally, the impact of car pollution (emitted soot) on skin was also investigated. Taken together, we demonstrate that the SpiderMass instrument opens the door to clinical, pharmaceutical and environmental domains for real-time, in vivo pharmacokinetic (Drug Metabolism and PharmacoKinetics, DMPK) analysis.

Experimental and theoretical investigations of a laser-produced aluminum plasma.

The formation and dynamics of a laser-produced aluminum plasma have been experimentally and theoretically investigated. The visible-emitting regions of the plasma form two structures with different lifetimes and expansion velocities. The first part of the transient ionic signal simultaneously recorded by a Langmuir probe presents an oscillatory structure. A hydrodynamic model in a nondifferentiable space-time has been established. The numerical simulation of the plasma expansion showed the plasma plume separation into two patterns. Moreover, the self-structuring of the interface appears through a negative differential conductance and the current oscillations are explained as being induced by thermal fluctuations that appear in the plasma cooling processes.

Fourier Transform Spectroscopy of the A'(1)Pi-X(1)Sigma(+) System of CaO.

The A'(1)Pi-X(1)Sigma(+) near-infrared system of CaO was observed for the first time at high resolution using a Fourier transform spectrometer. The A'(1)Pi-X(1)Sigma(+) chemiluminescence was excited in a Ca + N(2)O flame produced in a Broida-type oven. More than 3000 rotational lines, classified into 19 bands involving the A'(1)Pi 0 /= 2) levels with the nearby b(3)Sigma(+) (v-2) levels has been detected. An extended set of A'(1)Pi (v = 0-3) data has been obtained which is suitable for use in a future multistate deperturbation analysis of the a(3)Pi approximately A'(1)Pi approximately b(3)Sigma(+) approximately A(1)Sigma(+) complex of excited states. The new near-infrared spectra of the A'(1)Pi-X(1)Sigma(+) transition of CaO also permits the first direct high-resolution linkage between the orange and green systems and the near-infrared bands. Copyright 2000 Academic Press.

Fourier Transform Spectroscopy of Chemiluminescence from the SrO A(1)Sigma(+)-X(1)Sigma(+) Transition.

The A(1)Sigma(+)-X(1)Sigma(+) chemiluminescence spectrum of SrO was observed using a Fourier transform spectrometer. SrO was produced in a Broida-type oven from the Sr + N(2)O reaction. A total of 75 bands from (88)SrO, (87)SrO, and (86)SrO were measured in the range of 7600-13 600 cm(-1) at a resolution of 0.04 cm(-1). The vibrational levels of the ground state were observed up to v" = 12 and over 10 000 rovibrational lines with J as high as 153 were analyzed at a precision of about 0.005 cm(-1). Significantly improved spectral constants for the ground state were obtained by representing the perturbed excited state by term values and by adding the known microwave data and infrared data to our fit. Strong perturbations were observed in the upper A state. The vibrational levels of the A(1)Sigma(+) state were measured up to v' = 8 and some new perturbations are reported. Copyright 2000 Academic Press.

Characterization of the Ground State of Br(2) by Laser-Induced Fluorescence Fourier Transform Spectroscopy of the B(3)Pi(0(+))(u)-X(1)Sigma(+)(g) System.

The laser-induced fluorescence (LIF) spectrum of the B(3)Pi(0(+))(u)-X(1)Sigma(+)(g) system of Br(2) was recorded by Fourier transform spectroscopy (FTS). The LIF spectra were obtained by using continuous-wave dye laser excitation in the spectral region 16 800-18 000 cm(-1). About 1800 rotationally resolved lines were recorded in 96 fluorescence progressions, originating from the 10

Fourier Transform Emission Spectroscopy of the A2Pi-X2Sigma+ Transition of BeD.

The A2Pi-X2Sigma+ Deltav = 0 sequence of BeD was observed in the 19 500-20 800 cm-1 spectral region using a Fourier transform spectrometer. The emission spectrum was excited in a Be hollow cathode discharge lamp with a He/D2 gas mixture. The observed lines were assigned to the 0-0 to 6-6 bands. The Deltav = -1 sequence was too weak to be seen in our Fourier transform spectra. We therefore used a previously recorded but unpublished arc emission spectrum to identify the 0-1 to 5-6 Deltav = -1 bands. Consequently, all of the diagonal bands could be linked together and the vibrational intervals determined. The Deltav = 0 and Deltav = -1 data were fitted together in a global fit and effective constants derived. Using the information available from the study of the C2Sigma+-X2Sigma+ system [R. Colin, C. Drèze, and M. Steinhauer, Can. J. Phys. 61, 641 (1983)], the v = 8-12 vibrational levels of the ground state were added in a Dunham fit. A set of Dunham Y constants was determined for the X2Sigma+ state along with traditional equilibrium parameters for the A2Pi excited state. The equilibrium bond lengths were found to be 1.341742(5) Å for the ground state and 1.33309(4) Å for the excited state. A reanalysis of the previously published A2Pi-X2Sigma+ 0-0 to 3-3 Deltav = 0 bands of BeT [D. De Greef and R. Colin, J. Mol. Spectrosc. 53, 455-465 (1974)] was also performed. Copyright 1998 Academic Press.

Observation of TiF+ by Velocity Modulation Laser Spectroscopy and Analysis of the

The molecular ion TiF+ has been observed for the first time using high-resolution spectroscopy. The ions were produced in the positive column of an AC glow discharge with a gas mixture of He/TiF4. A single-mode cw dye laser along with the velocity modulation detection technique was used to record an absorption spectrum in the spectral region 16 800-18 600 cm-1. The observed system was assigned to the 0-0 and 1-1 bands of the [17.6]3Delta-X3Phi transition of TiF+. The rotational analysis of the main subbands has been performed up to J values equal to 77 and 56 for the 0-0 and 1-1 bands, respectively. Despite a careful search, no intercombination band was observed. A set of effective molecular parameters has been determined, characterizing the v = 0, 1 levels of the [17.6]3Delta and X3Phi states. The spin-orbit constants Ae and the vibrational constants omegae, omegaexe have been estimated for both electronic states, as well as their equilibrium distances Re (1.7509 and 1.7800) Å for the [17.6]3Delta and X3Phi states, respectively). Copyright 1998 Academic Press.

The Low-Lying States of He2.

The near-infrared emission spectrum of He2, excited in a Be hollow cathode discharge, has been recorded at high resolution using a Fourier transform spectrometer. The c3Sigma+g-a3Sigma+u (0-0, 1-1, 2-2, 1-0, and 2-1) and C1Sigma+g-A1Sigma+u (0-0 and 1-1) transitions have been observed in the 9000-15 000 cm-1 spectral region. A global analysis of the six lowest excited states of He2 (c3Sigma+g, b3Pig, a3Sigma+u, C1Sigma+g, B1Pig, and A1Sigma+u) was carried out by combining our measurements with previously reported infrared data for the b3Pig-a3Sigma+u system [S. A. Rogers et al., Mol. Phys. 63, 901 (1988)] and with laser measurements for the B1Pig-A1Sigma+u transition [H. Solka et al., Mol. Phys. 60, 1179 (1987)]. To account for the fine structure in the a3Sigma+u state, high precision r.f. measurements were included in the global fit. A consistent set of improved molecular constants was derived for the c3Sigma+g (v = 0, 1, and 2), b3Pig (v = 0 and 1), a3Sigma+u (v = 0, 1, and 2), C1Sigma+g (v = 0 and 1), B1Pig (v = 0 and 1), and A1Sigma+u (v = 0 and 1) levels. A study of the vibrational dependence of these constants was also performed, leading to the equilibrium parameters for the six electronic states. Copyright 1998 Academic Press.