Tara Salter

• PhD
• PostDoc Position at Imperial College London

The MAss Spectrometer for Planetary EXploration (MASPEX) is a high-mass-resolution, high-sensitivity, multi-bounce time-of-flight mass spectrometer (MBTOF) capable of measuring minor species with abundances of sub-parts-per-million in Europa’s sputter-produced and radiolytically modified exosphere and in its oceanic plumes. The goal of the MASPEX-E...

Evidence of liquid water is a primary indicator of habitability on the icy moons in our outer solar system as well as on terrestrial planets such as Mars. If liquid water-containing environments host life, some of its organic remains can be fossilized and preserved as organic biosignatures. However, inorganic materials may also be present and water...

Life detection missions to the outer solar system are concentrating on the icy moons of Jupiter and Saturn and their inferred subsurface oceans. Access to evidence of habitability, and possibly even life, is facilitated by the ejection of subsurface material in plumes and outgassing fissures. Orbiting spacecraft can intersect the plume material or...

Ancient martian organic matter is likely to take the form of kerogen-like recalcitrant macromolecular organic matter (MOM), existing in close association with reactive mineral surfaces, especially iron oxides. Detecting and identifying a biological origin for martian MOM will therefore be of utmost importance for life-detection efforts at Mars. We...

The icy moons of the outer solar system display evidence of subsurface liquid water and, therefore, potential habitability for life. Flybys of Saturn's moon Enceladus by the Cassini spacecraft have provided measurements of material from plumes that suggest hydrothermal activity and the presence of organic matter. Jupiter's moon Europa may have simi...

Monocyclic aromatic hydrocarbons such as benzene, toluene and xylene are thought to play an important role as precursors to the formation of polycyclic aromatic hydrocarbons (PAHs) and their methylated counterparts in a range of astrophysical environments. Benzene has been detected in two carbon rich objects and models have predicted that it could...

Temperature programmed desorption (TPD) and reflection absorption infrared spectroscopy (RAIRS) have been used to investigate the interactions between ethyl formate and water and ethyl formate and ethanol in model astrophysical ices adsorbed on a graphitic model grain surface. Experiments show that the ethyl formate forms hydrogen bonds to both wat...

Biomedical devices are complex products requiring numerous assembly steps along the industrial process chain, which can carry the potential of surface contamination. Cleanliness has to be analytically assessed with respect to ensuring safety and efficacy. Although several analytical techniques are routinely employed for such evaluation, a reliable...

The first comparative study of the surface behavior of four small aromatic molecules, benzene, toluene, p-xylene, and o-xylene, adsorbed on graphite at temperatures ≤30 K, is presented. Intermolecular interactions are shown to be important in determining the growth of the molecules on the graphite surface at low (monolayer) exposures. Repulsive int...

We present a novel UV/visible reflection-absorption spectrometer for determining the refractive index, n, and thicknesses, d, of ice films. Knowledge of the refractive index of these films is of particular relevance to the astrochemical community, where they can be used to model radiative transfer and spectra of various regions of space. In order t...

Alcohols, including 2-propanol, are important in a range of industrial applications, and are also found in cold astrophysical environments such as comets and interstellar space, where they are often frozen out on carbonaceous grain surfaces. In these regions, the interaction between alcohols and water ice plays a crucial role in the surface chemist...

The interstellar medium (ISM) is known to have rich chemistry, in spite of the low pressures and temperatures that occur there (~ 10-4 molecules cm-3 and ~ 10 K respectively). This chemical diversity is in part due to the presence of dust grains, which offer a surface on which processing and reactions of molecules occur. We present a newly installe...

Water ice is the most abundant solid in the Universe. Understanding the formation, structure and multiplicity of physicochemical roles for water ice in the cold, dense interstellar environments in which it is predominantly observed is a crucial quest for astrochemistry as these are regions active in star and planet formation. Intuitively, we would...

Interstellar clouds are known to consist of gas and dust grains. Understanding the processes which occur on the surface of these grains is of interest as they are in part responsible for the rich chemistry observed in the interstellar medium (ISM). A new ultraviolet/visible (UV/vis) spectrometer assembly is being designed and commissioned that will...

Interstellar clouds are known to consist of gas and dust grains. Understanding the processes which occur on the surface of these grains is of interest as they are in part responsible for the rich chemistry observed in the interstellar medium (ISM). A new ultraviolet/visible (UV/vis) spectrometer assembly is being designed and commissioned that will...

Liquid Extraction Surface Analysis (LESA) is a new, high throughput tool for ambient mass spectrometry. A solvent droplet is deposited from a pipette tip onto a surface and maintains contact with both the surface and the pipette tip for a few seconds before being re-aspirated. The technique is particularly suited to the analysis of trace materials...

Ambient mass spectrometry (AMS) is a new and versatile method for analysing a multitude of different sample types with the benefit of analysis at ambient pressure and the many other advantages that this entails. However, as these techniques are still in their infancy, metrological development of the techniques is essential. This is a critical step...

Latent fingerprints provide a potential route to the secure, high throughput and non-invasive detection of drugs of abuse. In this study we show for the first time that the excreted metabolites of drugs of abuse can be detected in fingerprints using ambient mass spectrometry. Fingerprints and oral fluid were taken from patients attending a drug and...

A VAMAS (Versailles Project on Advanced Materials and Standards) interlaboratory study for desorption electrospray ionisation mass spectrometry (DESI MS) measurements has been conducted with the involvement of 20 laboratories from 10 countries. Participants were provided with an analytical protocol and two reference samples: a thin layer of Rhodami...

Results are presented on the characterisation and optimisation of a non-thermal atmospheric pressure micro-plasma ion source used for ambient mass spectrometry imaging. The geometry of the experiment is optimised to produce the most intense and stable ion signals. Signal stabilities (relative standard deviation) of 2.3-6.5% are achieved for total i...

Many different types of samples have been analysed in the literature using plasma based ambient mass spectrometry sources, however, comprehensive studies of the important parameters for analysis are only just beginning. Here we investigate the effect of the sample form and surface temperature on the signal intensities in plasma assisted desorption...

Plasma-based desorption/ionization sources are an important ionization technique for ambient surface analysis mass spectrometry. In this paper, we compare and contrast three competing plasma based desorption/ionization sources: a radio-frequency (rf) plasma needle, a dielectric barrier plasma jet, and a low-temperature plasma probe. The ambient com...

Results are presented on the optimisation and characterisation of a plasma assisted desorption ionisation (PADI) source for ambient mass spectrometry. It is found by optimising the geometry we can increase ion intensities for valine and by tuning the plasma power we can also select a more fragmented or less fragmented spectrum. The temperature of t...

The authors report on a modified micro-plasma assisted desorption/ionisation (PADI) device which creates plasma through the breakdown of ambient air rather than utilising an independent noble gas flow. This new micro-PADI device is used as an ion source for ambient mass spectrometry to analyse species released from the surfaces of polytetrafluoroet...

A study of phenylalanine films of different thicknesses from submonolayer to 55 nm on Si wafers has been made using Bin+ and C60+ cluster primary ions in static SIMS. This shows that the effect of film thickness on ion yield is very similar for all primary ions, with an enhanced molecular yield at approximately 1 monolayer attributed to substrate b...

Two ambient ionisation techniques, desorption electrospray ionisation (DESI) and plasma assisted desorption ionisation (PADI), have been used to analyse personal care products (PCPs) on fixed fibroblast cell surfaces. The similarities and differences between the two techniques for this type of analysis have been explored in various ways. Here, we s...

The most prevalent of the ambient mass spectrometries, desorption electrospray ionisation (DESI), which provides highly sensitive mass spectrometry from surfaces without the constraint of vacuum, is compared with secondary ion mass spectrometry (SIMS). The potential of DESI has been demonstrated in a wide range of application areas, including foren...

Ambient mass spectrometry (ambient MS) is a powerful and rapidly growing new field that provides high sensitivity MS directly from surfaces at ambient pressure. There is now a rich evidence base in the published literature of the success of these methods for forensic analysis including: detection of explosives at nanogram levels; chemical compositi...

A hexagonal structure has been observed at ∼76°N on Saturn since the 1980s (Godfrey, D.A. [1988]. Icarus 76, 335–356). Recent images by Cassini (Baines, K., Momary, T., Roos-Serote, M., Atreya, S., Brown, R., Buratti, B., Clark, R., Nicholson, P. [2007]. Geophys. Res. Abstr. 9, 02109; Baines, K., Momary, T., Fletcher, L., Kim, J., Showman, A., Atre...

In desorption electrospray ionisation (DESI) the interaction between the electrospray and the surface is key to two important analytical parameters, the spatial resolution and the sensitivity. We evaluate the effect of the electrospray solvent type, organic solvent fraction with water, analyte solubility and substrate wettability on DESI erosion di...