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Chan QHS, Stroud R, Martins Z, Yabuta H. Concerns of Organic Contamination for Sample Return Space Missions. SPACE SCIENCE REVIEWS 2020; 216:56. [PMID: 32624626 PMCID: PMC7319412 DOI: 10.1007/s11214-020-00678-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 04/23/2020] [Indexed: 06/11/2023]
Abstract
Analysis of organic matter has been one of the major motivations behind solar system exploration missions. It addresses questions related to the organic inventory of our solar system and its implication for the origin of life on Earth. Sample return missions aim at returning scientifically valuable samples from target celestial bodies to Earth. By analysing the samples with the use of state-of-the-art analytical techniques in laboratories here on Earth, researchers can address extremely complicated aspects of extra-terrestrial organic matter. This level of detailed sample characterisation provides the range and depth in organic analysis that are restricted in spacecraft-based exploration missions, due to the limitations of the on-board in-situ instrumentation capabilities. So far, there are four completed and in-process sample return missions with an explicit mandate to collect organic matter: Stardust and OSIRIS-REx missions of NASA, and Hayabusa and Hayabusa2 missions of JAXA. Regardless of the target body, all sample return missions dedicate to minimise terrestrial organic contamination of the returned samples, by applying various degrees or strategies of organic contamination mitigation methods. Despite the dedicated efforts in the design and execution of contamination control, it is impossible to completely eliminate sources of organic contamination. This paper aims at providing an overview of the successes and lessons learned with regards to the identification of indigenous organic matter of the returned samples vs terrestrial contamination.
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Affiliation(s)
- Queenie Hoi Shan Chan
- Planetary and Space Sciences, School of Physical Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA UK
- Present Address: Department of Earth Sciences, Royal Holloway University of London, Egham Surrey, TW20 0EX UK
| | - Rhonda Stroud
- Code 6360, Naval Research Laboratory, Washington, DC 20375 USA
| | - Zita Martins
- Centro de Química Estrutural, Departamento de Engenharia Química, Instituto Superior Técnico (IST), Universidade de Lisboa, Avenida Rovisco Pais 1, 1049-001 Lisbon, Portugal
| | - Hikaru Yabuta
- Department of Earth and Planetary Systems Science, Hiroshima University, 1-3-1 Kagamiyama, Hiroshima, 739-8526 Japan
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Simkus DN, Aponte JC, Elsila JE, Parker ET, Glavin DP, Dworkin JP. Methodologies for Analyzing Soluble Organic Compounds in Extraterrestrial Samples: Amino Acids, Amines, Monocarboxylic Acids, Aldehydes, and Ketones. Life (Basel) 2019; 9:E47. [PMID: 31174308 PMCID: PMC6617175 DOI: 10.3390/life9020047] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 05/18/2019] [Accepted: 05/27/2019] [Indexed: 11/19/2022] Open
Abstract
Soluble organic compositions of extraterrestrial samples offer valuable insights into the prebiotic organic chemistry of the solar system. This review provides a summary of the techniques commonly used for analyzing amino acids, amines, monocarboxylic acids, aldehydes, and ketones in extraterrestrial samples. Here, we discuss possible effects of various experimental factors (e.g., extraction protocols, derivatization methods, and chromatographic techniques) in order to highlight potential influences on the results obtained from different methodologies. This detailed summary and assessment of current techniques is intended to serve as a basic guide for selecting methodologies for soluble organic analyses and to emphasize some key considerations for future method development.
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Affiliation(s)
- Danielle N Simkus
- NASA Postdoctoral Program at NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
- Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
| | - José C Aponte
- Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
- Department of Chemistry, Catholic University of America, Washington, D.C. 20064, USA.
| | - Jamie E Elsila
- Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
| | - Eric T Parker
- Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
| | - Daniel P Glavin
- Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
| | - Jason P Dworkin
- Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
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Eglinton G, Maxwell JR, Pillinger CT. Carbon chemistry of the Apollo lunar samples. Top Curr Chem (Cham) 2007; 44:83-113. [PMID: 4617936 DOI: 10.1007/3-540-06457-5_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Fox A. Chemical markers for bacteria in extraterrestrial samples. THE ANATOMICAL RECORD 2002; 268:180-5. [PMID: 12382316 DOI: 10.1002/ar.10152] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Interplanetary missions to collect pristine Martian surface samples for analysis of organic molecules, and to search for evidence of life, are in the planning phases. The only extraterrestrial samples currently on Earth are lunar dust and rocks, brought back by the Apollo (U.S.) and Luna (Soviet Union) missions to the moon, and meteorites. Meteorites are contaminated when they pass through the Earth's atmosphere, and during environmental exposure on Earth. Lunar fines have been stored on Earth for over 30 years under conditions designed to avoid chemical but not microbiological contamination. It has been extremely difficult to draw firm conclusions about the origin of chemicals (including amino acids) in extraterrestrial samples. Of particular concern has been the possibility of bacterial contamination. Recent work using state-of-the-art gas chromatography tandem mass spectrometry (GC-MS/MS) has dramatically lowered the chemical background, allowing a clear demonstration that lunar fines are remarkably different from terrestrial dust in that they generally lack certain chemical markers (muramic acid and 3-hydroxy fatty acids) characteristic of Earth's bacteria. Thus, lunar dust might be used as a negative control, in conjunction with GC-MS/MS analyses, in future analytical studies of lunar dust and meteorites. Such analyses may also be important in studies designed to search for the presence of life on Mars.
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Affiliation(s)
- Alvin Fox
- Department of Microbiology and Immunology, School of Medicine, University of South Carolina, Columbia 29208, USA.
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Brinton KL, Bada JL. A reexamination of amino acids in lunar soils: implications for the survival of exogenous organic material during impact delivery. GEOCHIMICA ET COSMOCHIMICA ACTA 1996; 60:349-354. [PMID: 11541128 DOI: 10.1016/0016-7037(95)00404-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Using a sensitive high performance liquid chromatography technique, we have analyzed both the hot water extract and the acid hydrolyzed hot water extract of lunar soil collected during the Apollo 17 mission. Both free amino acids and those derived from acid labile precursors are present at a level of roughly 15 ppb. Based on the D/L amino acid ratios, the free alanine and aspartic acid observed in the hot water extract can be entirely attributed to terrestrial biogenic contamination. However, in the acid labile fraction, precursors which yield amino acids are apparently present in the lunar soil. The amino acid distribution suggests that the precursor is probably solar wind implanted HCN. We have evaluated our results with regard to the meteoritic input of intact organic compounds to the moon based on an upper limit of < or = 0.3 ppb for alpha-aminoisobutyric acid, a non-protein amino acid which does not generally occur in terrestrial organisms and which is not a major amino acid produced from HCN, but which is a predominant amino acid in many carbonaceous chondrites. We find that the survival of exogenous organic compounds during lunar impact is < or = 0.8%. This result represents an example of minimum organic impact survivability. This is an important first step toward a better understanding of similar processes on Earth and on Mars, and their possible contribution to the budget of prebiotic organic compounds on the primitive Earth.
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Affiliation(s)
- K L Brinton
- Scripps Institution of Oceanography, University of California at San Diego, La Jolla 92093-0212, USA
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Sugiura Y, Woppmann A, Miljanich GP, Ko CP. A novel omega-conopeptide for the presynaptic localization of calcium channels at the mammalian neuromuscular junction. JOURNAL OF NEUROCYTOLOGY 1995; 24:15-27. [PMID: 7539483 DOI: 10.1007/bf01370157] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Voltage-sensitive Ca2+ channels are essential to transmitter release at the chemical synapse. To demonstrate the localization of voltage-sensitive Ca2+ channels in relation to the site of transmitter release, mouse neuromuscular junctions were double labelled with alpha-bungarotoxin and a novel voltage-sensitive Ca2+ channel probe, SNX-260, a synthetic analog of omega-conopeptide MVIIC. Similar to omega-conopeptide MVIIC, biotinylated SNX-260 blocked nerve-stimulated transmitter release at the mouse neuromuscular junction. Fluorescently-tagged biotinylated SNX-260 labelled the nerve terminal which appeared thinner than and was outlined by acetylcholine receptor clusters as seen in en face view. This SNX-260 labelling was inhibited by preincubation with unconjugated SNX-260. Side-views of the neuromuscular junction indicated that the SNX-260 labelling was on the synaptic side facing the acetylcholine receptor rather than on the nonsynaptic side of the nerve terminal. This presynaptic binding was confirmed by the absence of SNX-260 labelling in denervated muscles following a nerve cut or disjunction after collagenase treatment. Confocal microscopy revealed spots of SNX-260 labelling that may correlate with active zones. The SNX-260 labelling pattern was not affected by preincubation with unconjugated SNX-111 (omega-conopeptide MVIIA), an N-type voltage-sensitive Ca2+ channel blocker. These findings suggest that SNX-260 is a novel probe for localizing non-N type voltage-sensitive Ca2+ channels and that these voltage-sensitive Ca2+ channels are localized near the transmitter release sites at the mammalian motor nerve terminal membrane. The results are consistent with the suggestion that non-N, probably P/Q type voltage-sensitive Ca2+ channels mediate evoked transmitter release at the mammalian neuromuscular junction.
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Affiliation(s)
- Y Sugiura
- Department of Biological Sciences, University of Southern California, Los Angeles 90089-2520, USA
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Abstract
Confocal imaging was performed on the ceratomandibularis nerve muscle preparation of the lizard Anolis carolinensis, using 4-Di-2-ASP as a fluorescent probe. The imaging system consisted of a Sarastro Phoibos 1000 (Molecular Dynamics) scanning system and a Zeiss Universal microscope. The data were analyzed using the VANIS set of programs on a Silicon Graphics Personal Iris computer. A three dimensional reconstruction of the nerve terminals was performed using look-through and depth-coded projections. The volume of the nerve terminal was estimated in 15 neuromuscular junctions and found to be 84,835 microns 3 (+/- 8558 SEM). The largest diameter in each one of the 178 individual boutons was estimated from the look-through projections of 17 nerve terminals in 9 preparations. It was found to be 4.71 microns (+/- 0.08 SEM). The diameter perpendicular to the largest diameter in the same projection at 0 degrees was 3.3 microns (+/- 0.054 SEM). Thus it seems that the synaptic boutons of the ceratomandibularis are suitable for combined optical and electrophysiological recordings.
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Affiliation(s)
- N Melamed
- Department of Physiology, Hebrew University-Hadassah Medical School, Jerusalem, Israel
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Glavinović MI, Lee S, Miledi R. Effect of collagenase treatment and subsequent culture on rat muscle fiber acetylcholinesterase activity. J Neurosci Res 1987; 18:519-24. [PMID: 2830412 DOI: 10.1002/jnr.490180403] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
After collagenase treatment and mechanical disruption, acetylcholinesterase (AChE) activity on the surface of individual flexor brevis muscle fibers fell by 88%. During the next 48 hr in culture, surface AChE activity continued to decline, while intracellular activity changed little. After 1 week in culture total muscle fiber AChE activity fell to very low levels and intracellular AChE activity could no longer be detected, probably as a result of reduced synthesis and rapid externalization of intracellular AChE. Apart from the removal of most of the surface activity, cultured muscle fibers had similar AChE activity to muscle fibers that had been denervated in vivo, suggesting that the changes observed in culture reflect the loss of neuromuscular interaction and not to any contributory effects of the dissociation process. It is to be hoped that these results, along with the published results of Bekoff and Betz [J. Physiol, 271:25-40, 537-547], will serve as useful background data for those continuing to use adult dissociated muscle fibers in their studies.
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Affiliation(s)
- M I Glavinović
- Department of Biophysics, University College, London, England
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Alkadhi KA. Endplate channel actions of a hemicholinium-3 analog, DMAE. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 1986; 332:230-5. [PMID: 3012371 DOI: 10.1007/bf00504859] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effect of the hemicholinium-3 analog, DMAE, on endplate currents (EPC) was investigated in the transected cutaneous pectoris muscle of the frog using a conventional two-microelectrode voltage clamp. At a low concentration (5 microM), DMAE produced a long-lasting decrease in the rate constant of decay (alpha) and an increase in the peak current amplitude (Ip). At higher concentrations (10--100 microM), DMAE produced biphasic changes characterized by a transient, marked decrease of alpha and increase of Ip followed by a long-lasting marked increase of alpha and decrease of Ip. When DMAE was removed from the bath recovery from block was asymmetrical in that alpha recovered more quickly than did Ip. Pretreatment with neostigmine or collagenase partially antagonized the initial effects without affecting the steady state effects of DMAE, indicating that the initial effects of DMAE may be, at least in part, due to inhibition of the enzyme acetylcholinesterase. The drug reverses the normal voltage dependence of alpha without altering the single exponential nature of decay of the EPC. The inward EPC was more markedly blocked than outward EPC, resulting in a highly non-linear current-voltage relation with Ip decreasing with increasing hyperpolarization. This effect may indicate that DMAE causes a voltage-dependent block of closed acetylcholine-activated ion channels.
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Anglister L, Silman I. Molecular structure of elongated forms of electric eel acetylcholinesterase. J Mol Biol 1978; 125:293-311. [PMID: 215774 DOI: 10.1016/0022-2836(78)90404-7] [Citation(s) in RCA: 108] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Sketelj J, Brzin M. Increase in the apparent AChE activity in the mouse diaphragm induced by proteolytic treatment. J Neurochem 1977; 29:109-14. [PMID: 196040 DOI: 10.1111/j.1471-4159.1977.tb03931.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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14
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Inestrosa NC, Ramírez BU, Fernández HL. Effects of denervation and of axoplasmic transport blockage on the in vitro release of muscle endplate acetylcholinesterase. J Neurochem 1977; 28:941-5. [PMID: 68100 DOI: 10.1111/j.1471-4159.1977.tb10654.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Engel AG, Lambert EH, Gomez MR. A new myasthenic syndrome with end-plate acetylcholinesterase deficiency, small nerve terminals, and reduced acetylcholine release. Ann Neurol 1977; 1:315-30. [PMID: 214017 DOI: 10.1002/ana.410010403] [Citation(s) in RCA: 198] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A new myasthenic syndrome is described in a patient whose symptoms began soon after birth and included generalized weakness increased by exertion, easy fatigability, hyporeflexia, and refractoriness to anticholinesterase drugs. Electromyography showed a decremental response at all frequencies of stimulation and a repetitive response to single nerve stimulation. Miniature end-plate potentials (mepps) were of normal amplitude but of decreased frequency. The mepp duration and half-decay time were prolonged, and prostigmine was without any addtitional effect. The quantum content of the end-plate potential was decreased due to a reduced store of quanta immediately available for release, but the probability of release was normal. Quantitative electron microscopy demonstrated a 3-fold to 4-fold decrease of nerve terminal size and reduced postsynaptic membrane density. The postsynaptic folds showed focal degeneration, and many were distended by labyrinthine membranous networks that communicated with the synaptic space. Degenerating nuclei were found in the junctional sarcoplasm. The ultrastructural localization of the acetylcholine receptor protein was normal. Acetylcholinesterase (AChE) was absent from the motor end-plates by histochemical and electron cytochemical criteria. Biochemical studies indicated total absence of the end-plate-specific 16 S species of AChE and marked decrease in total muscle AChE. A congenital defect in the molecular assembly of AChE or in its attachment to the postsynaptic membrane might represent the basic abnormality and condition the morphological and physiological alterations.
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Csillik B. Synaptochemistry of acetylcholine metabolism in a cholinergic neuron. INTERNATIONAL REVIEW OF NEUROBIOLOGY 1975; 18:69-140. [PMID: 173665 DOI: 10.1016/s0074-7742(08)60034-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Dudai Y, Silman I. The effects of solubilization procedures on the release and molecular state of acetylcholinesterase from electric organ tissue. J Neurochem 1974; 23:1177-87. [PMID: 4375706 DOI: 10.1111/j.1471-4159.1974.tb12215.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Drachman DB. Trophic functions of the neuron. 3. Mechanisms of neurotrophic interactions. The role of acetylcholine as a neurotropic transmitter. Ann N Y Acad Sci 1974; 228:160-76. [PMID: 4135387 DOI: 10.1111/j.1749-6632.1974.tb20508.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Jain MK. Enzymic Hydrolysis of Various Components in Biomembranes and Related Systems. ACTA ACUST UNITED AC 1974. [DOI: 10.1016/s0070-2161(08)60848-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
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MODZELESKI VINCENTE, MODZELESKI JUDITHE, MOHAMMED MAJABBAR, NAGY LOISANNE, NAGY BARTHOLOMEW, McEWAN WILLIAMS, UREY HAROLDC, HAMILTON PAULB. Carbon Compounds in Pyrolysates and Amino Acids in Extracts of Apollo 14 Lunar Samples. ACTA ACUST UNITED AC 1973. [DOI: 10.1038/physci242050a0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Wilson WS, Cooper JR. The preparation of cholinergic synaptosomes from bovine superior cervical ganglia. J Neurochem 1972; 19:2779-90. [PMID: 4569108 DOI: 10.1111/j.1471-4159.1972.tb03815.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Gehrke CW, Zumwalt RW, Kuo K, Rash JJ, Aue WA, Stalling DL, Kvenvolden KA, Ponnamperuma C. Research for amino acids in lunar samples. SPACE LIFE SCIENCES 1972; 3:439-49. [PMID: 4650299 DOI: 10.1007/bf00926773] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Eglinton G, Maxwell JR, Pillinger CT. Lunar carbon chemistry: relations to and implications for terrestrial organic geochemistry. SPACE LIFE SCIENCES 1972; 3:497-506. [PMID: 4650305 DOI: 10.1007/bf00926780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Kaplan IR. Distribution and isotopic abundance of biogenic elements in lunar samples. SPACE LIFE SCIENCES 1972; 3:383-403. [PMID: 4568114 DOI: 10.1007/bf00926767] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Gibson EK, Moore CB. Compounds of the organogenic elements in Apollo 11 and 12 lunar samples: a review. SPACE LIFE SCIENCES 1972; 3:404-14. [PMID: 4568115 DOI: 10.1007/bf00926768] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Biemann K. In situ synthesis during organic analysis of lunar samples. SPACE LIFE SCIENCES 1972; 3:469-73. [PMID: 4650302 DOI: 10.1007/bf00926776] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Flory DA, Simoneit BR. Terrestrial contamination in Apollo lunar samples. SPACE LIFE SCIENCES 1972; 3:457-68. [PMID: 4650301 DOI: 10.1007/bf00926775] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Kvenvolden KA. Review of methods used in lunar organic analysis: extraction and hydrolysis techniques. SPACE LIFE SCIENCES 1972; 3:330-41. [PMID: 4568112 DOI: 10.1007/bf00926762] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Murphy RC. Aromatic and heteroatom-containing organic compounds in the lunar samples. SPACE LIFE SCIENCES 1972; 3:450-4. [PMID: 4650300 DOI: 10.1007/bf00926774] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Holland PT, Simoneit BR, Wszolek PC, Burlingame AL. Study of carbon compounds in Apollo 12 and 14 lunar samples. SPACE LIFE SCIENCES 1972; 3:551-61. [PMID: 4650306 DOI: 10.1007/bf00926782] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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