# Tritium Behavior from Vine to Wine
## 1 Introduction
There is a seasonal difference in the northern hemisphere caused by the interaction of the stratosphere and troposphere, with its level of precipitation being affected by several parameters such as altitude, distance from the ocean coast, or anthropogenic activities. Tritiated water makes up a part of biological organisms as tissue-free water tritium (TFWT). Considering plants, the water content makes up approximately 80-90% of the fresh mass, but this percentage depends on the species and their stage of development [12]. Tritium from a plant water pool can be labeled in organic matter as organically bound tritium (OBT) through metabolic processes, with the main process being photosynthesis. The nature of the chemical bonds of tritium defines the type of organic tritium, labile or not. Non-exchangeable OBT is tritium bound to carbon atoms, unlike exchangeable OBT, which is bound to sulfur, nitrogen, or oxygen atoms [13]. Exchangeable organic tritium is in equilibrium with the plant's water pool, and its turnover rate is the same as TFWT, influenced by the surrounding atmosphere and soil water [14]. At any rate, this labile organic tritium can be folded into biological macromolecules and can exchange very slowly due to its isolation from cellular water, with this behavior causing a long debate with the aim of defining organically bound tritium [15; 16]. If the plant's water pool rapidly reaches equilibrium with atmospheric moisture, TFWT reflects the tritium level of the environment when the sample was taken. This is not the case for organically bound tritium because it integrates the environmental tritium level of the growing period, which is why OBT is used for retrospective measures and is an important indicator of radioactivity monitoring programs near nuclear facilities. Assuming that the organically bound tritium level is related to the environment and, by consequence, to the location, we investigated its behavior in wines during the growing season in grapes and in wine to find a connection between its level and location. A tritium analysis of wines is usually carried out to reconstruct the actual precipitation tritium level in the past [17]. The principal isotope tools to authenticate the wine plant extracts are radiocarbon level, \({}^{13}\)C/\({}^{12}\)C ratios, and \({}^{2}\)H/\({}^{1}\)H ratios. Few published studies have investigated tritium concentration in natural and synthetic products or orange oils from different locations [18; 19]. In the case of wines, it has been confirmed that wine tritium data reflect not only the long-term trend or the seasonal variation in precipitation but also the local tritium level. To use its level in the authentication and geographical indication procedures of vine, it is necessary to understand tritium behavior from vine to wine. This paper presents the tritium concentrations in vine components (leaves, branches, grapes) from June to November and in the wine produced from harvested grapes for both tritium forms (TFWT and total OBT) in connection with environmental tritium concentration in air and precipitations, during the 2019-2023 vegetation periods, near Ramnicu Valcea city. To correlate the influence of meteorological conditions with tritium behavior in vines to grapes and wine, the following monthly parameters were recorded: temperature, air humidity, amount of precipitation, tritium level in the atmospheric vapor, and precipitation.