Mineralogical determination in situ of a highly heterogeneous material using a miniaturized laser ablation mass spectrometer with high spatial resolution

Abstract

Techniques enabling in situ elemental and mineralogical analysis on extraterrestrial planets are strongly required for upcoming missions and are being continuously developed. There is ample need for quantitative and high-sensitivity analysis of elemental as well as isotopic composition of heterogeneous materials. Here we present in situ spatial and depth elemental profiles of a heterogeneous rock sample on a depth-scale of nanometres using a miniaturized laser ablation mass spectrometer (LMS) designed for planetary space missions. We show that the LMS spectra alone could provide highly detailed compositional, three-dimensional information and oxidation properties of a natural, heterogeneous rock sample. We also show that a combination of the LMS and Raman spectroscopy provide comprehensive mineralogical details of the investigated sample. These findings are of great importance for future space missions where quick, in situ determination of the mineralogy could play a role in the process of selecting a suitable spot for drilling.

ORIGIN: a novel and compact Laser Desorption – Mass Spectrometry system for sensitive in situ detection of amino acids on extraterrestrial surfaces

“…Solar System objects, a novel and compact Laser Desorption/Ionization -Mass Spectrometry (LDI-MS) instrument has been designed and constructed (a schematic depiction is shown in Fig. 4), based on our experiences with existing systems and components 32,[37][38][39][40][41][42][43] . This system is called ORIGIN (ORganics Information Gathering INstrument).…”

Isotope abundance ratio measurements using femtosecond laser ablation ionization mass spectrometry

“…Our laboratory studies indicate that with a depth resolution in the sub-micrometer range, regions of interests, such as individual mineralogical grains or mineralogical layers, can be detected relatively easily within the sample illustrating the high sensitivity of our miniature LIMS system. 28,29,34,35,39…”

“…26,27 By applying the depth profiling technique, the chemical composition of micrometer-sized inclusions can be well-isolated from the host elements, without extensive sample preparation. 28,29 For larger samples, depth profiling offers also a means to gain information on sample homogeneity. But more importantly, because of the increased available statistics due to the profiling procedure, a filtering method can be applied which rejects, for example, mass spectra showing a poor spectral quality, spectra affected by significant isobaric interferences, or saturation problems of the detector system.…”

Laser Ablation/Ionisation Mass Spectrometry: Sensitive and Quantitative Chemical Depth Profiling of Solid Materials

“…[26] Unfortunately, the lander platform was cancelled later on due to budgetary reasons but since its first design in 2003 LMS has been continuously further developed. [4,13,17,[32][33][34][35][36][37][38][39][40][41][42] Today, LMS represents the most powerful and versatile LIMS system ever designed for in situ space investigations and exhibits top performing figures of merit. The system has the capability to conduct quantitative measurements with high detection sensitivity (10 ppb, atomic fraction) and with a dynamic range of about eight orders of magnitude.…”

“…The system has the capability to conduct quantitative measurements with high detection sensitivity (10 ppb, atomic fraction) and with a dynamic range of about eight orders of magnitude. [17,37] It allows measurements of element isotopes with high accuracy, [38] enables the elemental imaging of heterogeneous materials with micrometre resolution, [23,32,35,36] and provides high vertical depth profiling capabilities with sub-nanometre resolution. [4,13] The measurement capabilities of LMS for elemental imaging and depth profiling of solid materials are presented in more detail in section 3, where most recent and current measurements conducted on different sample materials, including the chemical mapping of an Allende meteorite sample, depth profiling of Si-supported Cu layers, chemical analysis of micrometre fossils embedded in an argonite matrix, and capabilities towards 3D elemental imaging of bronze-alloy samples are presented.…”