CHEMCAM; MISSION; UNIT

The SuperCam remote sensing instrument suite under development for the National Aeronautics and Space Administration's (NASA) Mars 2020 rover performs laser-induced breakdown spectroscopy (LIBS), remote Raman spectroscopy, visible and infrared (VISIR) reflectance spectroscopy, acoustic sensing, and high-resolution color imaging. The instrument builds on the successful architecture of the ChemCam instrument, which provides LIBS and panchromatic images on the Curiosity rover, adding remote Raman spectroscopy by frequency doubling the laser and using a gated intensified detector to obtain Raman signals at distances to 12 m. To the visible reflectance spectroscopy used by ChemCam, an acousto-optic tunable filter (AOTF)-based IR spectrometer is added to cover the 1.3-2.6 mu m range that contains important mineral signatures. A complementary metal-oxide semiconductor (CMOS) detector provides color (Bayer filter) images at a pixel resolution of 19 mu rad and an optical resolution of 30 mu rad. Sounds are recorded via a Knowles Electret microphone, which is the same one that was included but not used on two earlier missions. The acoustic signals of the LIBS plasmas will provide information on the hardness of the targets, while other sounds (wind, rover sounds) will also be recorded. The laser, telescope, IR spectrometer, and camera reside on the rover's mast and, are provided by the Centre national d'etudes spatiales (CNES), while the LIBS, Raman, and VIS spectrometers and data processing unit are built by Los Alamos National Laboratory (LANL) and reside in the rover body. A calibration target assembly provided by the University of Valladolid, Spain, resides on the back of the rover. The overall mass of the instrument suite is 10.7 kg.

PARTICLE-ICP-MS; RAMAN-SPECTROSCOPY; NANOPARTICLES; SILVER

Analytical spectroscopy is a mature field, but advances in instrumentation, measurement, and sample preparation techniques continue to be made. Much recent development has seen a heavy emphasis toward techniques and instrumentation that allow for noninvasive, in situ, and in vivo procedures while still retaining a high degree of sensitivity. This article will review some of this progress over the past two to three years across five major spectroscopic fields: Raman, laser-induced breakdown spectroscopy, X-ray fluorescence, infrared, and inductively coupled plasma techniques.

BUILDING EXPERT-SYSTEMS; FUEL PROPERTIES; SPECTROSCOPY; MODEL

A quiet but interesting trend has been occurring in material analysis, coincident with the rise of artificial intelligence (Al) and so-called ""deep"" machine learning methods. Astute spectroscopists have always known that there is more information in the spectra that they obtain than simply the molecular or atomic peaks that are directly measured. Particularly with methods such as infrared, Raman, and laser-induced breakdown spectroscopy (LIBS), the spectral background contains a wealth of information about the sample, and analytical combinations of the peaks can provide material properties. Traditionally, such analytical combinations of peaks were performed explicitly by analysts, but now information about material properties embedded in the spectra can be derived implicitly by Al and machine learning algorithms. This column introduces these ideas and touches on recent results indicative of what more may be coming in this direction.

PLASMA-MASS SPECTROMETRY; INDUCED BREAKDOWN SPECTROSCOPY; LASER-ABLATION; RESOLUTION; CHEMISTRY; TISSUES; METALS; CU

Elemental imaging is regarded as a valuable approach for a wide application range in modern medicine. Using tandem laser-ablation laser-inducedbreakdown spectroscopy (LA LIBS) coupled to inductively coupled plasma mass spectrometry (ICP-MS), high-sensitivity detection of trace metals can be combined with the possibility of analyzing nonmetallic bulk components of biological samples (for example, carbon, hydrogen, and oxygen). In this work, the applicability of the tandem LA LIBS approach for the laterally resolved elemental analysis of a mouse model tumor sample after administering cytostatic medication is demonstrated. Results show that trace elements can be detected using the LA-ICP-MS domain of the setup while major components of the samples are analyzed simultaneously using LIBS. By expanding the analyte range covered during one analysis, information could be extracted from the data set that is not accessible to either of the stand-alone analysis methods.

INDUCED BREAKDOWN SPECTROSCOPY; INDUCTIVELY-COUPLED PLASMA; MOLECULAR ISOTOPIC SPECTROMETRY; FLIGHT MASS-SPECTROMETRY; LA-ICP-MS; DEPTH PROFILE; LIBS; SAMPLES; STEEL

Laser ablation has become a dominant technology for direct solid sampling in analytical chemistry. Laser ablation refers to the process in which an intense burst of energy delivered by a short laser pulse is used to sample (remove a portion of) a material. The advantages of laser-ablation chemical analysis include direct characterization of solids, no chemical procedures for dissolution, reduced risk of contamination or sample loss, analysis of very small samples not separable for solution analysis, and determination of spatial distributions of elemental composition. This short review describes the most common approaches-laser-induced breakdown spectroscopy (LIBS) and laser-ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS)-and provides an introduction to laser-ablation molecular isotopic spectrometry (LAMIS).