title: Enhanced Resolution of Chiral Amino Acids with Capillary Electrophoresis for Biosignature Detection in Extraterrestrial Samples.
abstract: Amino acids are fundamental building blocks of terrestrial life as well as ubiquitous byproducts of abiotic reactions. In order to distinguish between amino acids formed by abiotic versus biotic processes it is possible to use chemical distributions to identify patterns unique to life. This article describes two capillary electrophoresis methods capable of resolving 17 amino acids found in high abundance in both biotic and abiotic samples (seven enantiomer pairs d/l-Ala, -Asp, -Glu, -His, -Leu, -Ser, -Val and the three achiral amino acids Gly, β-Ala, and GABA). To resolve the 13 neutral amino acids one method utilizes a background electrolyte containing γ-cyclodextrin and sodium taurocholate micelles. The acidic amino acid enantiomers were resolved with γ-cyclodextrin alone. These methods allow detection limits down to 5 nM for the neutral amino acids and 500 nM for acidic amino acids and were used to analyze samples collected from Mono Lake with minimal sample preparation.
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology , 4800 Oak Grove Drive, Pasadena, California 91109, United States.
authors.forename: Jessica S
authors.identifier: 0000-0003-2890-4901
authors.initials: JS
authors.lastname: Creamer
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology , 4800 Oak Grove Drive, Pasadena, California 91109, United States.
authors.forename: Maria F
authors.initials: MF
authors.lastname: Mora
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology , 4800 Oak Grove Drive, Pasadena, California 91109, United States.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Willis
mesh_terms: D000596:Amino Acids / Q000032:analysis*; D019075:Electrophoresis, Capillary / Q000379:methods*; D005118:Extraterrestrial Environment / Q000737:chemistry*; D060106:Lakes / Q000737:chemistry*; D008958:Models, Molecular; D013237:Stereoisomerism; D047408:gamma-Cyclodextrins / Q000737:chemistry
chemical_list: D000596:Amino Acids; D047408:gamma-Cyclodextrins