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Capillary Electrophoresis Analysis of Organic Amines and Amino Acids in Saline and Acidic Samples Using the Mars Organic Analyzer

Stockton, Amanda M. and Chiesl, Thomas N. and Lowenstein, Tim K. and Amashukeli, Xenia and Grunthaner, Frank and Mathies, Richard A. (2009) Capillary Electrophoresis Analysis of Organic Amines and Amino Acids in Saline and Acidic Samples Using the Mars Organic Analyzer. Astrobiology, 9 (9). pp. 823-831. ISSN 1557-8070.

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The Mars Organic Analyzer (MOA) has enabled the sensitive detection of amino acid and amine biomarkers in laboratory standards and in a variety of field sample tests. However, the MOA is challenged when samples are extremely acidic and saline or contain polyvalent cations. Here, we have optimized the MOA analysis, sample labeling, and sample dilution buffers to handle such challenging samples more robustly. Higher ionic strength buffer systems with pKa values near pH 9 were developed to provide better buffering capacity and salt tolerance. The addition of ethylaminediaminetetraacetic acid (EDTA) ameliorates the negative effects of multivalent cations. The optimized protocol utilizes a 75mM borate buffer (pH 9.5) for Pacific Blue labeling of amines and amino acids. After labeling, 50mM (final concentration) EDTA is added to samples containing divalent cations to ameliorate their effects. This optimized protocol was used to successfully analyze amino acids in a saturated brine sample from Saline Valley, California, and a subcritical water extract of a highly acidic sample from the Río Tinto, Spain. This work expands the analytical capabilities of the MOA and increases its sensitivity and robustness for samples from extraterrestrial environments that may exhibit pH and salt extremes as well as metal ions.

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Additional Information:© 2009 Mary Ann Liebert, Inc. Published in Volume: 9 Issue 9: December 7, 2009. We thank Daniel Glavin (NASA Goddard Space Flight Center) and Mary Sue Bell (NASA Johnson Space Center) for providing ASAP sample KF03-A from the Rı´o Tinto. Microdevices were fabricated in the UC Berkeley Microfabrication Laboratory by Wai K. Chu. This research was supported by NASA grants NNG04GB75G and NNX08AR09G, NSF grant EAR 0433802 (T.K.L.), and by the Jet Propulsion Laboratory and the California Institute of Technology under contract 1297596.
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NSFEAR 0433802
Subject Keywords:Amino acid analysis—Astrobiology—Planetary exploration—Lab-on-a-chip—Micro total analysis systems.
Issue or Number:9
Record Number:CaltechAUTHORS:20100106-135224323
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Official Citation:Amanda M. Stockton, Thomas N. Chiesl, Tim K. Lowenstein, Xenia Amashukeli, Frank Grunthaner, Richard A. Mathies. Astrobiology. November 2009, 9(9): 823-831. doi:10.1089/ast.2009.0357.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:17083
Deposited By: Jason Perez
Deposited On:07 Jan 2010 21:39
Last Modified:03 Oct 2019 01:22

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