Percorrer por autor "Rego, Andreia"
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- Measuring minerals in pseudocereals using inductively coupled plasma optical emission spectrometry : what is the optimal digestion method?Publication . Nascimento, Ana C.; Motta, Carla; Rego, Andreia; Delgado, Inês; Santiago, Susana; Assunção, Ricardo; Matos, Ana Sofia; Santos, Mariana; Castanheira, IsabelPseudocereals have gained attention due to their adaptability to different climates, high nutritional value, and suitability for gluten-free and plant-based diets. However, a challenge lies in the necessary adaptations in the diet pathways, mainly due to the lack of matrix-matching metrological tools. To address this problem, we developed a classification system to support laboratory decisions without shaped Proficiency Testing (PT) or Certified/Standard References Material. This system evaluates method performance through limit of detection (LOD), maximum uncertainty, and statistical comparison. For that matter, the mineral contents (Cu, Mn, Fe, Zn, Mg, P, Ca, K, and Na) of quinoa (Chenopodium quinoa), amaranth (Amaranthus caudatus), and buckwheat (Fagopyrum esculentum) were determined, using three different digestion methods, including dry-ashing, microwave, and graphite block acid digestion. A decision was reached concerning the optimal digestion method to be employed, with the results classified into three categories: (i) “rejected if results failed in two categories; (ii) “use with caution” if results were not satisfactory in one category; or (iii) “accepted”, if the results passed in all the categories. The system efficacy was exemplified by the effectiveness of dry-ashing and graphite block acid digestion by comparison with microwave digestion. Neither dry-ashing nor graphite block acid digestion can be recommended as an alternative method to the microwave digestion method when all the prioritized nutrient minerals are understudied. Although the microwave method is preferable for multi-elemental analysis, it is possible to obtain, with caution, comparable results from all the digestion methods if a higher relative combined uncertainty is defined (target uncertainty < 11%) under the assumption that this is suitable for the study.
- Study around the Barroso mine (Portugal) : baseline levels of lithium for assessing future exposure and risks from Li mining activityPublication . Jesus, Susana; Ventura, Marta; Assunção, Ricardo; Gueifão, Sandra; Delgado, Inês; Rego, Andreia; Ribeiro, Mariana; Martins, Marta; Neves, Orquídia; Coelho, InêsThe energetic green transition is increasing the demand for lithium (Li) exploitation. However, the Li supply faces challenges like limited reserves and environmental concerns. This pioneer study aims to characterize the Li concentrations in the region around the Barroso mine, in Portugal, by collecting and analyzing samples of cabbage, potato, drinking and irrigation water and soil from two nearby sites, and performing a preliminary exposure and risk assessment of local populations. Li levels ranged between 20 and 589 μg/kg in cabbages (n = 23), 2.3–21 μg/kg in potatoes (n = 21), 1.1–5.9 μg/L in drinking water (n = 10), 1.1–15 μg/L in irrigation water (n = 23) and 35–121 mg/kg in soils (n = 23). Significant differences in Li content between sampling sites were observed only for cabbage samples. The risk assessment revealed that none of the participants exceeded the provisional reference dose (p-RfD) (2 μg/kg bw/day), with a hazard quotient (HQ) < 1, suggesting no health concerns for the population. It is expected that the studied area will be affected by the future expansion of the mine concession, thus this pioneer study is crucial for future research as it establishes a initial database for evaluating the potential impact of mining activity on the environment and the population's exposure to Li.