The origin of life from inanimate matter is still an open question, and our knowledge is still very limited. In this sense, prebiotic chemistry seeks to study and understand how chemical reactions may have contributed to the origin of life. Minerals are of great relevance to prebiotic chemistry, as they may have preconcentrated precursors of biomolecules or biomolecules from diluted solutions, provided protection for biomolecules against UV radiation and hydrolysis, catalysing their reactions and played the role of a primitive genetic code. Montmorillonite, a prebiotic mineral, was shown to be able to adsorb adenine and later also histidine. In addition, histidine adsorption did not displace adenine from the montmorillonite. Kinetic experiments showed that using a whole period of time (7 days) it was not possible to adjust the data to any mathematical kinetic model. Thus, the data were separated into four different adsorption ranges: range 1 (0–60 min), range 2 (60–4320 min), range 3 (4320–7200 min) and range 4 (7200–10 080 min). Range 1 showed adsorption that was too fast, meaning no variations in the adsorption data, and the data of range 3 did not fit in any model used in this work. Thus, range 2 (60–4320 min) and range 4 (7200–10 080 min) were analysed. The adsorption kinetics of histidine adsorption indicated two reaction steps, a quick step (60–4320 min), following the pseudo-first-order model, followed by a slower step (7200–10 080 min) of the pseudo-second order. With these results, isotherms were constructed with times of 1 h and 7 days. The results of the quick step (1 h) showed a reaction that was not thermodynamically favoured. For this time range, Gibbs energy values obtained ranged between 5 and 10 kJ mol−1 at temperatures of 20, 35 and 50°C, and the adsorption occurred due to the balance shift of increase in histidine concentrations. The isotherms of the slow step (7 days) presented negative values, showing a more favourable reaction with Gibbs energy values ranging between −5 and −11 kJ mol−1. The mathematical modelling of the data indicates that seawater ions are crucial in the adsorption process. Thus, the study provided essential information for prebiotic chemistry, showing that time and the reaction medium should always be taken into account.

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益生元化学条件下改性蒙脱石对组氨酸的吸附：热力学和动力学研究

无生命物质的生命起源仍然是一个悬而未决的问题，我们的知识仍然非常有限。从这个意义上说，益生元化学旨在研究和了解化学反应如何促成了生命的起源。矿物质与益生元化学密切相关，因为它们可能具有预先浓缩的生物分子前体或稀释溶液中的生物分子，为生物分子提供免受紫外线辐射和水解的保护，催化它们的反应并发挥原始遗传密码的作用。蒙脱石是一种益生元矿物质，被证明能够吸附腺嘌呤，后来还吸附组氨酸。此外，组氨酸吸附并没有从蒙脱石中置换腺嘌呤。动力学实验表明，使用整个时间段（7 天）不可能将数据调整到任何数学动力学模型。因此，数据分为四个不同的吸附范围：范围 1（0-60 分钟）、范围 2（60-4320 分钟）、范围 3（4320-7200 分钟）和范围 4（7200-10080 分钟）。范围 1 显示吸附太快，这意味着吸附数据没有变化，范围 3 的数据不适合本工作中使用的任何模型。因此，分析了范围 2（60-4320 分钟）和范围 4（7200-10 080 分钟）。组氨酸吸附的吸附动力学表明两个反应步骤，一个快速步骤（60-4320 min），遵循伪一级模型，然后是伪二级模型的较慢步骤（7200-10 080 min）。根据这些结果，构建了 1 小时和 7 天的等温线。快速步骤 (1 小时) 的结果显示出在热力学上不受欢迎的反应。在这个时间范围内，获得的吉布斯能量值介于 5 到 10 kJ mol 之间-1在 20、35 和 50°C 的温度下，由于组氨酸浓度增加的平衡偏移而发生吸附。慢步（7 天）的等温线呈现负值，表明吉布斯能量值在 -5 和 -11 kJ mol 之间的反应更有利-1. 数据的数学模型表明海水离子在吸附过程中至关重要。因此，该研究为益生元化学提供了重要信息，表明应始终考虑时间和反应介质。