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We present the analysis of a 2.06 Ga apatite crystal obtained from an ultramafic phoscorite rock from the Phalaborwa Complex (Limpopo Province, South Africa) [1]. A space-prototype laser ablation ionisation mass spectrometer (LIMS) [2,3] was used to study the chemical composition of the sample. Mass spectra were recorded from a sample area of 0.6x0.6 mm2, with a spatial resolution of 30 μm and sub-micrometre depth resolution.Apatite is a calcium phosphate mineral expressed by the chemical stoichiometric formula [Ca5(PO4)3(F, Cl, OH)]. The halogen site, occupied by F, Cl, and OH, corresponds to an isomorpous series with fluor-, chlor- and hydroxyl-apatite end members, respectively. Apatite, being an accessory mineral in igneous and other rocks, commonly contains a range of other elements that do not fit well into the major rock forming minerals, such as rare earth elements (REE). These are suitable targets for investigating physical and chemical conditions in igneous rocks and the volatile evolution of magmas.The analysis of the spectra recorded with our LIMS system for the abundances of the elements of interest at each location were performed in two steps. First, the abundances of each element across the sampled area were compiled in element maps. And second, an unsupervised machine learning algorithm based on clustering and network analysis was applied to the data set of analysed mass spectra to separate it into groups of distinct chemical composition. Subsequently, a more detailed analysis was conducted on each of the recovered groups to assign the corresponding mineral. In addition to the group of spectra belonging to apatite, which was assigned to fluorapatite, other minerals were identified, amongst others olivine. This method yields an unsupervised approach to identify different mineralogical entities present within a sample. This network analysis method was previously applied to a 1.88 Ga Gunflint sample (Ontario, Canada) to separate spectra recorded from the host (chert) from spectra containing signatures of organic matter from fossilized microbes [4].Given that the data were recorded using a miniature mass spectrometer designed for space flight, this analysis demonstrates the analytical capabilities of our LIMS system that could be achieved in-situ on other planetary bodies in our Solar System, for example on the Moon or on Mars. The current performance of this miniature LIMS instrument to study the chemical composition of apatite is sufficiently high to measure volatiles (H, F, Cl) and nearly all relevant mineral and partially trace elements (Na, C, Mg, Si, S, K, Mn, Fe, Sr, Ba), including REE (La, Ce, Pr, Sm) which allows for a systematic quantitative analysis of their distribution.[1] Tulej, M. et al., 2022, https://doi.org/10.3390/universe8080410.[2] Riedo, A. et al., 2012, https://doi.org/10.1002/jms.3104.[3] Tulej, M. et al., 2021, https://doi.org/10.3390/app11062562.[4] Lukmanov, R.A. et al., 2022, https://doi.org/10.3389/frspt.2022.718943

The search for evidence of extant and extinct life on Mars is of big interest for future robotic and human exploration missions. The properties and characteristics of evaporites such as gypsum make them an easily accessible target in the search for biosignatures of extraterrestrial life. On Earth, a diverse microbial community inhabits gypsum in modern brines. These microbes are easily entombed within gypsum due to its fast precipitation. Studies of primary lower gypsum deposits, accumulated in the Mediterranean Basin during the Messinian salinity crisis (5.97 – 5.33 Ma), revealed a well-preserved and prominent archive of diverse microbial life. Similar archives might exist on Mars considering the desiccation of large bodies of water there, representing a promising target for exploring the possibility of life on Mars. The recent imaging mapping and analysis done by orbiters and rovers on the surface of Mars led to the discovery of abundant gypsum and evaporite minerals suggesting the evaporation of large lakes and lacustrine systems and as the surface of Mars dried out, hypersaline lakes would have filled the ancient lake system. A similar scenario happened on Earth when thick layers of gypsum were deposited during the Messinian salinity crisis when the Mediterranean was turned into the youngest salt giant in Earth’s history.Previous chemical and molecular laser mass spectrometry analyses done on microfossils preserved in different rock records showed these instruments’ ability to detect biosignatures related to ancient life. In this study, we successfully investigated the chemical composition of fossil filaments interpreted to be benthic microbial assemblages dominated by chemotrophic sulfide-oxidizing bacteria, sulfate-reducing bacteria, and planktonic cyanobacteria. This study demonstrated the efficiency of a miniaturized next-generation Laser based Mass Spectrometer (LMS) designed for future space explorations in the detection of microbial chemical biosignatures trapped in Messinian gypsum, shading light to the potential application to the search for life on Mars. Literature Natalicchio, M., Birgel, D., Dela Pierre, F., Ziegenbalg, S., Hoffmann-Sell, L., Gier, S., & Peckmann, J. (2022). Messinian bottom-grown selenitic gypsum: An archive of microbial life. Geobiology, 20, 3– 21. https://doi.org/10.1111/gbi.12464.Bayles, M., Belasco, B.C., Breda, A.J., Cahill, C.B., Da Silva, A.Z., Regan, M.J., Jr., Schlamp, N.K., Slagle, M.P. and Baxter, B.K. (2020). The Haloarchaea of Great Salt Lake as Models for Potential Extant Life on Mars. In Extremophiles as Astrobiological Models (eds J. Seckbach and H. Stan-Lotter). https://doi.org/10.1002/9781119593096.ch4.Lukmanov, RA., Tulej, M., Ligterink, NFW., et al. ( 2021). Chemical identification of microfossils from the 1.88-Ga Gunflint chert: Towards empirical biosignatures using laser ablation ionization mass spectrometer. Journal of Chemometrics, 35 ( 10):e3370. doi:10.1002/cem.3370.

Direct analysis of micrometer-scale features embedded in solid samples of a wide chemical variety is an integral part of many fields in geo-, geobio-, and planetary sciences. Examples range from microscopic mineral inclusions in meteoritic material, (e.g., zircons, CAIs, chondrules, etc.) to biological inclusions in a variety of mineralogical host materials, e.g., (putative) fossils of microbial species. In many of these use-cases, the determination of the element and/or isotope composition, specifically those of minor or trace abundance, is of prime interest, meaning mass spectrometry is typically the preferred analysis technique.As a result, a growing group of instruments has been (and are being) developed specifically with the purpose of element and/or isotope analysis of microscale features in solid hosts, each with its specific advantages and limitations. Perhaps the most well-known technique is (nano)SIMS, which boasts analysis spot sizes down to the nanometer level as well as ppm to ppb detection limits, but struggles with quantitativeness and capital and operating expenses. In the field of laser-based solid sampling mass spectrometric techniques, LA-ICP-MS has become a well-established technique, mainly due to its reproducibility and ease of operation. However, due to necessity to transport particles from the ablation plume to the ICP, this technique is inherently limited through fractionation effects and isobaric interferences with the plasma and carrier gas. Furthermore, sample dilution in the plasma and the subsequent loss of sample at the ICP-MS interface result in diminished limits of detection.Another member of the laser-based solid sampling techniques is Laser Ablation Ionization Mass Spectrometry (LIMS), in which the ions present in the ablation plume are directly introduced into the mass spectrometer. This direct sampling of the ablation plume results in both a significant advantage over LA-ICP-MS (high sensitivity) and a challenge (mass resolution). The limited mass resolution of typical LIMS instruments often makes (quantitative) analysis challenging due to isobaric interferences, especially when applied to more complex materials. To solve this issue, the Laser Mass Spectrometer – Gran Turismo (LMS-GT) was developed at the University of Bern with the aim of achieving mass resolutions sufficient to resolve the most common isobaric interferences (M/ΔM = 10.000).Over the last years, commissioning and continuous improvement of the instrument has been ongoing, which has led to a set of analytical performance characteristics which highlight the potential complementary value of LMS-GT. In this talk, we will discuss the latest technological developments1, latest analytical performance metrics (mass resolution, mass accuracy, limits of detection, etc.), and element and isotope ratio accuracies2,3. We will also discuss a case-study in which LMS-GT was used to study fossilized microbial inclusions in Gunflint chert4, highlighting both the potential strength and challenges for LMS-GT in a geo- and geobiosciences context.1. Gruchola, S. et al., Int. J. Mass Spectrom. 474, 116803 (2022).2. Wiesendanger, R. et al., J. Anal. At. Spectrom. 34, 2061–2073 (2019).3. de Koning, C. P. et al., Int. J. Mass Spectrom. 470, 116662 (2021).4. Lukmanov, R. A. et al., Front. Space Technol. 3, (2022).

With NASA’s increased focus on exploration of our Moon within the Artemis program, new scientific goals have been formulated to expand our knowledge on the history of our Solar System, including the evolution of the Earth-Moon system. Additionally, establishing a permanent human presence on the Moon has been declared a goal of the Artemis program, the success of which will inevitably depend on in-situ resource utilization (ISRU) of lunar material. In turn, successful ISRU requires methods capable of analysing and selecting suitable materials in place. To support these tasks, sensitive instrumentation capable of determining the elemental and isotope composition of geological samples from the lunar surface is essential. Consequently, defining and determining the technical requirements of such instrumentation, constructing it accordingly, and verifying its performance are all crucial steps in maximising the scientific return of such a mission. Furthermore, NASA’s Artemis program also aims to facilitate future human exploration of Mars, which implies that instrumentation applied successfully on the Moon might find its application on the Martian surface in the future. We present our progress in designing, constructing and testing a prototype miniature laser ablation ionisation mass spectrometer (LIMS) for in-situ measurements on the lunar surface. The finalised instrument will be deployed on the Commercial Lunar Payload Service (CLPS) mission CP-22 scheduled for launch in late 2026 and land in the lunar south pole region. Our miniature reflectron-type time-of-flight mass analyser (160 mm x Ø 60 mm) designed for in-situ space applications was coupled to a pulsed Nd:YAG microchip laser system (SB1 series, Bright Microlaser Srl, Italy) operating at 532 nm (max. laser pulse energy of 40 µJ, pulse repetition rate of 100 Hz). The laser source and the optics were mounted colinearly to the optical axis of the instrument assembly into a cage system. This construction is modelled after the envisioned flight design, and therefore used to determine the required optical and electronic performance characteristics of the future flight instrument. The current flight design will be presented as well. Furthermore, validation of the technical implementation and verification of the scientific requirements will be discussed through the results of laser ablation experiments conducted on lunar regolith simulant.

In-situ Mars exploration requires new promising instrumentation that will be capable of delivering highly accurate chemical information about soils and rocks present at the Martian surface. Specific attention is drawn to the instruments that are capable of identifying extinct or extant microbes within the bulk of various solid samples (Tulej et al., 2015; Westall et al., 2015; Wiesendanger et al., 2018). A miniature Laser Ablation/Ionization Mass Spectrometer (LIMS) developed at the University of Bern is among the valid candidates (Wurz et al., 2012). The size of the mass analyzer is only Ø 60 mm × 160 mm and thus capable of being deployed on a rover or lander platform. In this contribution, we will present data collected from a 1.88 Ga Gunflint sample using a deep UV fs laser system as ablation ion source. The gunflint chert sample contains a population of microfossils entombed in the silica matrix and was chosen as a Martian analogue. Using the high stability of the UV laser and consequent uniform ablation, we performed large-scale spectra collection (90’000) in two modes - chemical imaging and depth profiling. With the current setup, we achieved a diameter of the analytical spot of ~10 µm for the depth profiling and ~5 µm for the imaging. Our results reveal that our LIMS instrument can identify the location of the microfossil lamination area as well as single microfossils by chemical means. We show how single mass unit spectral decomposition and subsequent kernel clustering reveal masses and intensity regions unique to the microfossils and inorganic host, thus providing the opportunity for automated identification of the spectra that are collected from the microfossils. We also show how transforming spectral intensities into spectral proximities can help to navigate the rich multidimensional datasets. We also address common interpretation problems in LIMS, when multiple mineralogical inclusions contribute to the output spectra acquired within the single analytical spot using ρ-networks and Principal Component Analysis (PCA). In combination with analysis of spectral proximities, this approach is particularly useful in attempts to assess the biogenicity of the putative terrestrial microfossils as well as potential Martian microfossils. Additionally, we discuss the data analysis pipeline and chemical composition of the microfossils and surrounding inorganic host in detail. Tulej M., Neubeck A., Ivarsson M., Riedo A., Neuland M. B., Meyer S., and Wurz P. (2015) Chemical Composition of Micrometer-Sized Filaments in an Aragonite Host by a Miniature Laser Ablation/Ionization Mass Spectrometer. Astrobiology, 15: 669-682. Westall F., Foucher F., Bost N., Bertrand M., Loizeau D., Vago J. L., Kminek G., Gaboyer F., Campbell K. A., Bréhéret J.-G. and others. (2015) Biosignatures on Mars: What, Where, and How? Implications for the Search for Martian Life. Astrobiology, 15: 998-1029. Wiesendanger R., Wacey D., Tulej M., Neubeck A., Ivarsson M., Grimaudo V., Moreno-García P., Cedeño-López A., Riedo A., Wurz P. and others. (2018) Chemical and Optical Identification of Micrometer-Sized 1.9 Billion-Year-Old Fossils by Combining a Miniature Laser Ablation Ionization Mass Spectrometry System with an Optical Microscope. Astrobiology, 18: 1071-1080. Wurz P., Abplanalp D., Tulej M., Iakovleva M., Fernandes V. A., Chumikov A., and Managadze G. G. (2012) Mass spectrometric analysis in planetary science: Investigation of the surface and the atmosphere. Solar System Research, 46: 408-422.

The identification of microbial remains on planetary bodies is an extremely challenging endeavor, requiring the utilization of novel measurement techniques and modern analytical approaches. We performed an extensive study of the chert sample from Gunflint formation (1.88 Ga) containing populations of Precambrian microfossils with a laser ablation ionization mass spectrometer (LIMS) (Riedo et al., 2013; Wiesendanger et al., 2018) intended for application in space. Chemical characterization on microscale can open a new perspective in the identification of microbial remains, where morphological features might be lost and provide additional lines of evidence towards proving biogenicity of a given putative sample. Chert from the Gunflint formation in this study is considered as a Martian analogue where remains of microfossils are mainly concentrated within circular and tubular structures, which are primarily made from collapsed cell walls entombed within silica.We sampled the microfossils and surrounding chert (host area) with fs UV laser with a spot size of 8 μm and retrieved intensities of 180 consecutive single mass peaks from each mass spectrum. We collected 60’000 mass spectra and build an intensity-based classifier, intended to process large datasets from cherts and identify their classes in an automatic regime. Using elemental pair-to-pair correlation analysis, we identified relevant masses for each given mineralogical class. Additionally, we will present results of chemical imaging of the sample and discuss in details the chemical composition of microfossils and surrounding chert as well as technical aspects of the identification of spectra from the microfossils.We will show how rich spectral information can be reduced to the low dimensional domain using principal components analysis and used for successful classification. Moreover, we will present the established workflow and discuss possibilities to extend this approach to other astrobiologically relevant formations, such as phosphates, carbonates, hydrothermal silicates. Future Mars exploration with enabling technologies as machine learning and big data processing coupled with high-output instrumentation such as laser ablation ionization time-of-flight mass spectrometry has the capacity to improve scientific return and achieve stated objectives and therefore should be given appropriate attention in the future missions. Riedo, A., Neuland, M., Meyer, S., Tulej, M., & Wurz, P. (2013). Coupling of LMS with a fs-laser ablation ion source: Elemental and isotope composition measurements. Journal of Analytical Atomic Spectrometry, 28(8), 1256–1269.Wiesendanger, R., Wacey, D., Tulej, M., Neubeck, A., Ivarsson, M., Grimaudo, V., … Wurz, P. (2018). Chemical and Optical Identification of Micrometer-Sized 1.9 Billion-Year-Old Fossils by Combining a Miniature Laser Ablation Ionization Mass Spectrometry System with an Optical Microscope. Astrobiology, 18(8), 1071–1080.

The search for life is one of the key topics in modern space science. The JUICE mission of the European Space Agency ESA will investigate Jupiter and its icy moons Ganymede, Callisto and Europa, with Europa being an example of a potentially habitable world around a giant gas planet. The Particle and Environment Package, PEP, on board of the JUICE spacecraft will investigate Jupiter’s icy moons and their environment. The Neutral gas and Ion Mass spectrometer NIM will investigate the icy moon’s exospheres to investigate their formation and the interaction processes of the exospheres with the moons’ surface and Jupiter’s strong magnetic field. It will enhance our understanding of the processes involved in the interactions of ion bombardment on the icy moons' surfaces. From these measurements, we will derive the moons’ surface composition and their formation processes.NIM is a time-of-flight mass spectrometer with two particle entrances: an open-source entrance to measure neutral particles and ions directly and a close source entrance where neutral particles get thermalized before entering the sensor’s ionization region. This allows detecting of particles with high speeds. NIM has a specially designed ion storage source and an ion-mirror to double the flight distance of the produced ions by keeping the sensor at a minimal size.In this contribution, we show calibration results of the NIM flight spare instrument on one hand operated with laboratory and on the other operated with flight electronics. We demonstrate the performance of NIMs ion-source, verify the performance of the closed-source antechamber. NIM has a demonstrated mass resolution of m/Δm 800.

Mass spectrometric measurements conducted on various amino acids that are relevant to life as we know it on Earth are presented using ORIGIN. ORIGIN is a novel Laser Desorption Mass Spectrometric setup designed for in situ operation on planetary surfaces, including the icy surfaces on ocean worlds such as Europa and Enceladus. Laser desorption measurements were conducted on single amino acids and amino acid mixtures to investigate their fragmentation behaviour at given laser settings. Simple mixtures consisting of four amino acids and a complex mixture consisting of ten amino acids at various concentrations and with components ranging from Glycine to Tyrosine are investigated. The unique fragmentation patterns observed for the single amino acids allowed successfully the identification of amino acids in the complex mixture. The measurement capabilities of ORIGIN are of high importance as ORIGIN represents an alternative instrument to traditional space instruments for future space exploration missions devoted to the detection of life. Introduction The icy moons Europa and Enceladus of Jupiter and Saturn, respectively, represent promising objects in our Solar System that may host life in their liquid oceans underneath their ice crust. Through cracks in the ice shells signatures of life, such as amino acids, lipids, among others, may escape the liquid oceans and form deposits on the surface, which can be probed more easily by instrumentation than in the ocean directly. However, in situ operation of instrumentation designed for the detection of signatures of life is extremely challenging and sensitive instrumentation is required to withstand the harsh environmental conditions that exist at the ice surfaces. In our contribution, we present the current figures of merit of our newly developed laser desorption mass spectrometric instrument, called ORIGIN. Experimental Sample Preparation. Solutions of single amino acids (ranging from Gly to Tyr) at a concentration of 100 µM, mixtures of four amino acids (Ala, Asp, Met, and Tyr, at total concentrations of 100µM), and a mixture of ten amino acids (Gly, Ala, B-Ala, Ser, Asp, Leu, Glu, Met, His, Tyr) of a total mixture concentration of 100 µM (singles have a concentration down to 2.5 µM), were prepared and drop cast (1 µl) under atmospheric condition and at room temperature into shallow cavities (0.2 mm x Ø 3 mm) on sample holders [1]. LDMS Measurements. Measurements were conducted using our newly developed laser desorption mass spectrometric setup, called ORIGIN [1]. ORIGIN consists of a miniature reflectron-type time-of-flight mass analyser (160 mm x Ø 60 mm) [2,3] that is coupled to a nanosecond pulsed laser system (pulse width ~3 ns, wavelength λ = 266 nm, pulse repetition rate = 20 Hz). The mass analyser is located within a vacuum chamber that is evacuated to a base pressure down to the mid 10-8 mbar level. An optical beam delivery system guides the laser pulses from the nanosecond laser system towards the vacuum chamber, towards the lens system that is just installed outside, above the entrance window of the vacuum chamber. The laser pulses are focussed through the mass analyser towards the sample surface to induce the desorption of the analyte of interest. The sample holder that consists of cavities is placed outside the laser focus to gently desorbed the analyte (laser spot size at the level of ~30 µm). With each laser pulse, sample material is desorbed and partially ionised. Only positively charged species can enter the entrance ion optics of the mass analyser, and are subsequently guided to the detector system. The charged species arrive in time sequences at the detector system, and a quadratic equation is used for the conversion of the time-of-flight spectra to mass spectra. In this study, we discuss measurements conducted on single amino acids, four simple mixtures of amino acids at different concentrations, and on a mixture that consists of ten amino acids at different concentrations down to 2.5 µM level. The biofilms were sampled spot-wise by applying 100 laser shots per position. In total 40 positions were sampled on each biofilm (single amino acid, simple and more complex mixtures). Results and Discussion From the measurements of single amino acids their fragmentation behaviour can be determined accurately. Subsequently, these fragmentation patterns allowed for the direct identification of amino acids in the more simple mixtures and the more complex mixture by fitting the mass spectra of the mixtures. Moreover, it is possible to simulate the entire laser desorption mass spectrometric of the mixtures. In Figure 1 the laser desorption measurements conducted on one of the simple mixtures are shown (top panel) whereas at the bottom panel the simulated spectrum is shown. As can be observed, both spectra are almost identical to each other, which is of high importance as the simulation allows reliable identification of amino acids within a mixture. Figure 1: Measured (top) and simulated (bottom) laser desorption mass spectra of a simple amino acid mixture that consists of Ala, Met, Asp, and Tyr. Summary and Conclusions Laser desorption mass spectrometric studies were conducted on single amino acids to investigate their simple and robust fragmentation pattern and on simple and more complex mixtures of amino acids. Through simple fragmentation patterns observed for single amino acid measurements, amino acids in simpler and more complex mixtures could be identified directly. Moreover, the robust fragmentation patterns observed allowed to simulate mass spectra of amino acid mixtures. The latter is of high importance as it allows reliable post-measurement identification of amino acids. The study presented is of high importance for future space exploration missions because ORIGIN represents a promising analytical tool for the identification of signatures of life, if present, on e.g., the icy surface of Europa. References [1] Ligterink, N.F.W., Grimaudo, V., Moreno-García, P., Lukmanov, R., Tulej, M., Leya, I., Lindner, R., Wurz, P., Cockell, C.S., Ehrenfreund, P., and Riedo, A., Nature Sci. Rep., Vol. 10, 2020, 9641. [2] Riedo, A., Bieler, A., Neuland, M., Tulej M., and Wurz, P., J. Mass Spectrom., Vol. 48, 1 - 15, 2013. [3] Riedo, A., Meyer, S., Heredia, B., Neuland, M., Bieler, A., Tulej, M., Leya, I., Iakovleva, M., Mezger K., and Wurz P., Planet. Space Sci., Vol. 87, 1 - 13, 2013.

Searches for the past and present life on the planetary surfaces will be involving multilevel characterisation of the planetary rocks and soils within potentially habitable environments. Some up to three billion years old stromatolites or fossilised bacterial colonies are particularly interesting. They are found on the Earth and thought to be earliest life forms preserved within the terrestrial sedimentary rocks and can be a benchmark for searches of bio-relevant objects on planetary surfaces. By combining the microscope-camera system and mass analyser one can identify micro-fossilised material within the rocks by means of specific morphological details and characteristic chemical composition. We discuss the results of the studies on ancient microfossils obtained by space-born instrumentation, microscope-camera system combined with laser mass spectrometer. Both, the microscope imaging and chemical analyses can be conducted with micrometre spatial resolution. We demonstrate that the morphological record is helpful but not sufficient to identify bio-relevant material. Yet, while combined with elemental and isotope and with help depth profiling method, the compositional analysis can distinguish between abiotic and biological nature of the material. Detection of biosignature in measurements of fossilised materials with a miniature laser ablation ionisation mass analyser. [1] M. Tulej, A. Neubeck, M. Ivarsson, A. Riedo, M.B. Neuland, S. Meyer, P. Wurz, Chemical Composition of Micrometer-Sized Filaments in an Aragonite Host by a Miniature Laser Ablation/Ionization Mass Spectrometer, Astrobiology, 15 (2015) 669-682. [2] A. Neubeck, M. Tulej, M. Ivarsson, C. Broman, A. Riedo, S. McMahon, P. Wurz, S. Bengtson, Mineralogical determination in situ of a highly heterogeneous material using a miniaturized laser ablation mass spectrometer with high spatial resolution, International Journal of Astrobiology, 15 (2016) 133-146. [3] R. Wiesendanger, D. Wacey, M. Tulej, A. Neubeck, M. Ivarsson, V. Grimaudo, P. Moreno-Garcia, A. Cedeno-Lopez, A. Riedo, P. Wurz, Chemical and optical identification of micrometer-sized 1.9 billion-year-old fossils by combining a miniature laser ablation ionization mass spectrometry system with an optical microscope, Astrobiology, 18 (2018) 1071-1080. [4] A. Riedo, A. Bieler, M. Neuland, M. Tulej, P. Wurz, Performance evaluation of a miniature laser ablation time-of-flight mass spectrometer designed for in situ investigations in planetary space research, Journal of Mass Spectrometry, 48 (2013) 1-15. [5] M. Tulej, A. Riedo, M.B. Neuland, S. Meyer, P. Wurz, N. Thomas, V. Grimaudo, P. Moreno-Garcia, P. Broekmann, A. Neubeck, M. Ivarsson, CAMAM: A Miniature Laser Ablation Ionisation Mass Spectrometer and Microscope-Camera System for In Situ Investigation of the Composition and Morphology of Extraterrestrial Materials, Geostand Geoanal Res, 38 (2014) 441-466.

In situ identification of life signatures on Solar System bodies other than Earth is extremely challenging and demands for sophisticated and sensitive instrumentation for their detection. Life signatures can be grouped into six different categories, ranging from biomolecules (e.g., lipids and amino acids), to microstructures (such as microfossils) [1]. Sulphur fractionated element isotopes belong to another important category and are of high interest to current astrobiology. In this contribution, we report on a novel measurement protocol, which is dedicated to measure accurately fractionated sulphur isotopes in different Mars analogue materials with an accuracy at the 34δ level using our miniature and sensitive Laser Ablation Ionisation Mass Spectrometer (LIMS) that was designed for space exploration missions.The applied LIMS instrument in this study consists of a miniature reflectron-type time-of-flight mass analyser (160 mm x Ø 60 mm) and a femtosecond laser system (λ = 775 nm, τ ~190 fs) used as ablation and ionization source [2-3]. By means of irradiance studies performed on the Mars analogues, optimal measurement conditions could be elaborated, which allowed to measure sulphur fractionation with an accuracy at the 34δ level.All measurements presented here were conducted on five very different Mars analogues that were collected at different extreme field sites on Earth, including Rio Tinto in Spain and Movile and Sulphur caves in Romania. The analogues differ strongly in their total sulphur weight abundance, which range from ~5 to ~95 %, and in their fractionation degree of sulphur (34δ from about +8 to -7). In comparison to the state-of-the-art sulphur isotope measurements the LIMS measurements showed an accuracy of ~1.5 34δ. The measurement protocol is simple and sufficiently accurate for in situ application. It will provide valuable information of e.g., geochemical processes occurred on Solar System body surfaces, and will enable the identification of sulphuric-based life in case the fractionation is above fractionation induced by geochemical processes.References1) E. Hays, H.V. Graham, D.J. Des Marais, E.M. Hausrath, B. Horgan, T.M. McCollom, M. Niki Parenteau, S.L. Potter-McIntyre, A.J. Williams and K.L. Lynch, "Biosignature Preservation and Detection in Mars Analog Environments", Astrobiol., 17, 2017, 363 – 400.2) Riedo, M. Neuland, S. Meyer, M. Tulej and P. Wurz, "Coupling of LMS with a fs-laser ablation ion source: elemental and isotope composition measurements", J. Anal. At. Spectrom., 28, 2013, 1256 – 1269.3) Tulej, A. Neubeck, M. Ivarsson, A. Riedo, M.B. Neuland, S. Meyer and P. Wurz, "Chemical composition of micrometer-sized filaments in an aragonite host by a miniature laser ablation/ionization mass spectrometer", Astrobiol., 15, 2015, 669 - 682.

Stable nickel isotopes are known to fractionate by biological processes and their measurements can be important biomarker. In searches for ancient fossilised materials such as microbial cells, the Ni isotope fractionation record can be preserved after death and fossilization of microstructures. Typically, transition metal isotopes in microfossils are difficult to measure accurately because of their low concentration in the fossil. Furthermore, microsized fossil structures are difficult to isolate from the host phase. Thus, the measurement of their chemical composition can be conducted only by a few analytical methods. We have applied femtosecond-laser ablation/ionisation time-of-flight mass spectrometry (LIMS) to measure chemical composition of the fossilised material embedded in the aragonite phase and accurately derive the Ni isotopic fractionation pattern. High resolution depth profiling method was applied to isolate fossilised material composition from the host phase. The mass peak intensity correlation and peak integration methods were subsequently applied to derive isotope concentrations. The accuracies and precision in permill level or better of the isotope values were achieved. For comparison the studies of Ni isotopes were conducted on inorganic samples. The instrument used in the studies is a miniature mass analyser developed for space research holding promisses that differentiation between abiotic and biogenic microstructures in rocks can be studied also in situ on the surfaces of Solar System bodies.References1. U. Rohner et al., Meas. Sci. Technol. 14 (2003) 2159–21642. A. Riedo et al., JAAS, 28:1256–1269, 20133. A. Neubeck et al., Int. J. Astrobiology, 15, 133-146, 20164. M. Tulej et al., Astrobiology, 2015, DOI: 10.1089/ast.2015.1304;JAAS,33(8):1292-1303, 20185. S. Meyer et al., J. Mass Spectrom. 2017, DOI: org/10.1002/jms.3964 6. R. Wisendanger et al., J. Chemometrics, 2018, DOI: 10.1002/cem.30817. V. Grimaudo et al., Anal. Chem., 2018, DOI: 10.1021/acs.analchem.7b05313

Grasslands represent canopies with a complex structure where sources and sinks of ammonia (NH3) may coexist at the plant level. Moreover, management practices such as mowing, hay production and grazing may change the composition of the sward and hence the source-sink relationship at the canopy level as well as the interaction with the atmosphere. There is therefore a need to understand the exchange of ammonia between grasslands and the atmosphere better, especially regarding the location and magnitude of sources and sinks. Fluxes of atmospheric NH3 within a grassland canopy were assessed in the field and under controlled conditions using a dynamic chamber technique (cuvette). These cuvette measurements were combined with extraction techniques to estimate the ammonium (NH4+) concentration and the pH of a given part of the plant or soil, leading to an estimated ammonia compensation point (Cp). The combination of the cuvette and the extraction techniques was used to identify the potential sources and sinks of NH3 within the different compartments of the grassland: the soil, the litter or senescent "litter leaves", and the functioning "green leaves". A set of six field experiments and six laboratory experiments were performed in which the different compartments were either added or removed from the cuvettes. The results show that the cuvette measurements agree with the extraction technique in ranking the strength of compartment sources. It suggests that in the studied grassland the green leaves were mostly a sink for NH3 with a compensation point around 0.1–0.4 μg m−3 and an NH3 flux of 6 to 7 ng m−2 s−1. Cutting of the grass did not increase the NH3 fluxes of the green leaves. The litter was found to be the largest source of NH3 in the canopy, with a Cp of up to 1000 μg m−3 NH3 and an NH3 flux up to 90 ng m−2 s−1. The litter was found to be a much smaller NH3 source when dried (Cp=160 μg m−3 and FNH3=35 ng m−2 s−1 NH3). Moreover emissions from the litter were found to vary with the relative humidity of the air. The soil was a strong source of NH3 in the period immediately after cutting (Cp=320 μg m−3 and FNH3=60 ng m−2 s−1), which was nevertheless always smaller than the litter source. The soil NH3 emissions lasted, however, for less than one day, and were not observed with sieved soil. They could not be solely explained by xylem sap flow extruding NH4+. These results indicate that future research on grassland-ammonia relationships should focus on the post-mowing period and the role of litter in interaction with meteorological conditions.

Grassland is a canopy with a complex structure where sources and sinks of ammonia may coexist at the plant level. Moreover, management practices such as mowing, hay production and grazing, may change the composition of the sward and hence the source-sinks relationship at the canopy level as well as the interaction with the atmosphere. There is therefore a need to better understand the exchanges of ammonia between grasslands and the atmosphere, especially regarding the locations of sources and sinks and their magnitudes. Fluxes of atmospheric ammonia (NH3) within a grassland canopy were assessed in the field and under controlled conditions using a dynamic chamber technique (cuvette). These cuvette measurements were combined with extraction techniques to estimate the ammonium (NH4+) concentration and the pH of a given part of the plant or soil, leading to an estimated ammonia compensation point (Cp). The combination of the cuvette and the extraction techniques was used to identify the potential sources and sinks of NH3 within the different compartments of the grassland: the soil, the litter or "litter leaves", and the functioning "green leaves". A set of 6 field experiments and 6 laboratory experiments were performed in which the different compartments were either added or removed from the cuvettes. This study shows that the cuvette measurements agree with the extraction technique in ordering the strength of compartment sources. It suggests that in the studied grassland the green leaves were mostly a sink for NH3 with a compensation point around 0.1–0.4 μg m−3 NH3 and an NH3 flux of 6 to 7 ng m−2 s−1 NH3. Cutting of the grass did not increase the NH3 fluxes of the green leaves. The litter was found to be the largest source of NH3 in the canopy, with a compensation point up to 1000 μg m−3 NH3 and an NH3 flux up to 90 ng m−2 s−1 NH3. The litter was found to be a much smaller NH3 source when dried (Cp=160 μg m−3 NH3 and FNH3=35 ng m−2 s−1 NH3). Moreover emissions from the litter were found to vary with the relative humidity of the air. The soil was a strong source of NH3 in the period immediately after cutting (Cp=320 μg m−3 NH3 and FNH3=60 ng m−2 s−1 NH3), although always relatively smaller than the litter source. The soil NH3 emissions were, however, not lasting more than one day, and were not observed with sieved soil. Soil emissions not be solely explained by xylem sap flow extruding NH4+. These results indicate that future research on grassland-ammonia relationships should focus on the post-mowing period and the role of litter in interaction with meteorological conditions.

The exchange of ammonia between crop canopies and the atmosphere depends on a range of plant parameters and climatic conditions but little is known about effects of management factors. We have here investigated the ammonia exchange potential of a grass sward dominated by Lolium perenne in response to cutting and fertilization. Tall grass showed a low potential for NH3 emission before cutting. During re-growth after cutting, leaf tissue concentrations of NO3−, NH4+, soluble N and total N increased along with apoplastic NH4+ concentrations. In contrast, apoplastic pH decreased resulting in largely unaltered NH3 emission potential. A high potential for NH3 emission was shown by the plant litter. Fertilization with 100 kg N ha−1 one week after cutting caused the apoplastic NH4+ concentration of the newly emerging leaves to increase dramatically. The apoplastic NH4+ concentration peaked the day after the fertiliser was applied and thereafter decreased over the following 10 days until reaching the same level as before fertilisation. A positive correlation was found between NH4+ concentrations in leaf apoplast, bulk tissue and litter throughout the experimental period. Leaf soluble N was negatively correlated with apoplastic NH4+ concentration whereas total N was weakly correlated with NH4+ concentrations in leaf tissue and soil.