Soluble Organics in Astromaterials
Soluble Organics in Astromaterials
SOAL research focuses on the analysis of organic molecules of astrobiological relevance in order to better understand the prebiotic inventory available on Earth during the origins of life. This includes analyses of molecules directly isolated from extraterrestrial samples, such as meteorites and returned samples, in situ analyses of distant objects, as well as analyses of laboratory reaction products.
Meteorites are particularly interesting to study because they are the surviving fragments of asteroids (and perhaps comets) that have fallen to Earth; these objects formed during the early evolution of the solar system, and we can study them in the lab. While prebiotic chemistry on Earth has been overwritten by ~4 billion years of biotic chemistry and geology, meteorites are relatively pristine chemical "fossils," having recorded chemistry that took place prior to the origins of life. Meteorites, therefore, offer authentic snapshots of prebiotic chemistry in our solar system.
Many types of organic molecules have been found to be indigenous to meteorites, including molecules critical for contemporary organisms such as amino, hydroxy, and carboxylic acids, aldehydes and ketones, amines, polycyclic aromatic hydrocarbons, nucleobases, and sugars and sugar acids. Amino acids in particular have been measured in dozens of meteorites whose parent asteroids have experienced varying degrees of thermal alteration and aqueous alteration. The overall abundances and isomeric distributions of meteoritic amino acids have been shown to vary depending on the alteration history of a given meteorite, providing clues to how these molecules were formed. Because asteroids have been impacting the Earth since its formation, meteorites may have played a significant role in adding to the inventory of molecules available during the origins of life.
The overall abundances and isomeric distributions of meteoritic amino acids have been shown to vary depending on the alteration history of a given meteorite, providing clues to how these molecules were formed. Because asteroids have been impacting the Earth since its formation, meteorites likely played a significant role in adding to the inventory of molecules available during the origins of life.
A 2010 study using ultra high-resolution mass spectrometry estimated that the soluble organic content of the Murchison meteorite contains tens of thousands of unique molecular formulas, spanning millions of isomers. Only a small fraction of these molecules has been uniquely identified, leaving a great deal of work to be done on organic chemistry in the early Solar System. In addition, the analysis of different kinds of meteorites has revealed significant variation of meteoritic organics depending on the mineralogy and alteration history of meteorites, highlighting our rather limited understanding of what compounds were available at the origins of life on Earth, and elsewhere in the universe.
SOAL has an array of analytical instrumentation. This includes a Waters Xevo G2-XS quadrupole/time of flight hybrid mass spectrometer (QToF-MS) with an Acquity H-class Ultra Performance Liquid Chromatograph (UPLC) with photodiode array (PDA) and fluorescence (FL) detectors, electrospray ionization (ESI), atmospheric pressure photoionization (APPI), Direct Analysis in Real Time (DART), and Desorption Electrospray Ionization (DESI) sources; a Thermo Fortis Triple Quadrupole Mass Spectrometer coupled with an Ultimate 3000 UPLC with FL and PDA detectors, and ESI and APPI sources; and a Thermo Trace 1310 gas chromatograph with a Thermo ISQ mass spectrometer (GC-MS) and CDS Analytical pyrolysis system.
py-GC-MS: This gas chromatograph-mass spectrometer enables the analysis of volatile and semi-volatile compounds. Gas or liquid samples can be injected directly into the gas chromatograph or introduced by heating solid samples with the pyrolysis probe. UPLC-QqQ-MS: This liquid chromatograph is connected to fluorescence and photodiode array detectors, along with triple quadrupole mass spectrometer detectors, enabling analysis of polar and semi-polar compounds up to 4,000 m/z. UPLC-QToF-MS: This liquid chromatograph is connected to a quadrupole-time of flight hybrid mass spectrometer in addition to fluorescence and photodiode array detectors. These detectors enable sensitive analyses of polar and semi-polar compounds up to 100,000 m/z with high resolution and mass accuracy.