The radiolysis of aqueous solutions of malic acid

Origins Life Evol Biosphere

Navarro‐González

1990

Abstract. 2/-radiolysis of 0.8 tool dm 3 aqueous, oxygen-free acetic acid solutions was investigated m the presence or absence of Na-montmorillonite (1-3 g per 10 cm ~). The systems were irradiated at their natural pH (3.5), and 25 °C in a dose range from 0.01 to 500 kGy. H2, CH4, CO, C%, and a variety of polycarboxylic acids were formed in all systems. The major features of the radiolysis in the presence of clays were: (1) More solute molecules were decomposed; (2) Carbon dioxide was produced in higher yield; (3) The yield of methane was unaffected; and (4) 44% less polycarboxylic acids were formed. Three possible mechanisms that could account for the observed changes are suggested. The results are important in understanding heterogeneous processes in radiation catalysis and might be significant to prebiotic chemistry.

Section: Carboxylic Acidsmentioning

confidence: 99%

The γ-irradiation of aqueous acetic acid-clay suspensions

Origins Life Evol Biosphere

Navarro‐González

1990

“…Radiation-induced oxidation reactions play a fundamental role in the formation and decomposition of critical bioorganic molecules in the early Earth [1][2][3]. Even when early Earth conditions are difficult to simulate in the laboratory, there are few experimental setups studying the stability and formation of some compounds of biological importance under a high radiation field [4][5][6]. Succinic acid (HOOC-(CH 2 ) 2 -COOH) is one of the molecules formed in prebiotic experiments [6], it has been found in carbonaceous chondrites [7,8], it is essential in chemical evolution processes as a starting material for more complex molecules and participates in the metabolic pathways of living beings [9].…”

Section: Introductionmentioning

confidence: 99%

Radiation Induced Reactions of Succinic Acid in Aqueous Solution: An Agent-Based Model

Rivera

Ramos-Beltran

J. Nucl. Phy. Mat. Sci. Rad. A.

2020

An approach to studying the formation of critical bio-organic compounds in the early Earth is to simulate in the laboratory possible processes that may occur in primitive scenarios. In this context, it can be studied the evolution of succinic acid in an aqueous media exposed to gamma radiation, as starting material produced more complex prebiotic molecules. To describe the products generated by the interaction of the different elements under radiation, there is a mathematical model that considers chemical reactions as nonlinear ordinary differential equations based on the mass balance of all the species, that has been implemented here by an agent-based model. In this simulation, each chemical species involved is considered as an agent that can interact with other species with known reaction rates, and the radiation is taken as a factor that promotes product formation. The results from the agentbased model are compared with the molar concentrations of succinic acid, and its products obtained in the lab. Simulation shows the exponential decomposition of succinic acid due to gamma radiation at room temperature in agreement with the laboratory model.

“…In the laboratory is common to use radiation induced chemical oxidation reactions to study the formation of biologically relevant molecules in space bodies due to the energy transfer by radiation [1][2][3][4][5][6]. Chemical analysis, pulse radiolysis, and competition kinetic methods have been employed experimentally to obtain the large number of rate constants involved in these reactions [7][8][9][10][11]. Mathematical models can follow the dynamics of the radiation induced chemical reactions using a system of coupled nonlinear ordinary differential equations [12][13][14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Radiolysis of Nucleosides: Study of Sedimentary Microenvironment Models for the Protection of Bio-Organic Molecules on Early Earth

Aguilar-Ovando

2017

JNP

Chemical Fricke dosimeter in the laboratory can be submitted to gamma radiation at low temperatures to study the evolution of oxidation reactions induced by radiation, a key process to understand the formation of complex molecules. Products generated by the interaction of the different elements under radiation can be determined through a mathematical model that considers chemical reactions as coupled nonlinear ordinary differential equations involving the mass balance of all the species in the reaction. In this paper is implemented an alternative way of solving this system of equations, species' concentrations are calculated through an agent-based model implemented in Python. The model is a modified version of the prey-predator model where each chemical specie involved is considered as an agent that can interact with other specie with known reaction rates leading to production (source terms) and to destruction (sink terms). Here, the radiation is a factor that affects product formation while the bath temperature modifies the reaction speed. This model can reproduce experimental concentrations of products and the consumption of ferrous ions from a laboratory reaction of irradiation of iron salt solutions at 3 different temperatures (dry ice, liquid nitrogen, and room temperature).