388 (gastric stage) (gastrointestin al stage) Average [mg/kg] 11.48 5.81 Standard Deviation (SD) 1.89 0.40 Relative standard deviation (RSD%) 17 7 Confidence interval obtained using Student’s T distribution [mg/kg] [1.6 – 2.3] [5.63- 5.99] Certified concentration BGS102 [mg/kg] 13 5.4 Certified confidence interval [7-19] [3-7.8] Table N°2 Summary of operational validation results of the MABIOMET device in the Laboratory of Soil and Environment, UTEM. Study Variables Original UBM method expected values Experimentally obtained values Rotation speed device 30 RPM Maximum 30-28.5 RPM Bioreactor thermal control 37 ± 2 °C 37 ± 0.5 °C RSD% removal of the device (%relative standard deviation) 10-20% 7-17% 3.2 RESULTS AND DISCUSSION MABIOMET prototype tests with representative tailings samples.: During this experimental stage, the gastric and gastrointestinal stage extracts were obtained in the MABIOMET prototype from representative samples of the five abandoned tailings under study of environmental interest of Andacollo. Bioaccessibility was determined considering the bioaccessible metal in the gastric and gastrointestinal stages obtained by extraction from MABIOMET. The bioaccessible quantification of Cu, Fe, Pb, and Zn was measured by AAS and, in the case of As, by ICP-MS. The experimental procedure implemented allowed for the quantification of the bioaccessibility of four metals (Cu, Fe, Pb, Zn) and the metalloid (As) in five representative tailings of environmental interest in the city of Andacollo in the Coquimbo Region of Chile. Herein, it was established in the analysed tailings that, lead’s, bioaccessibility was established between 20% and 45%, primarily occurring in the gastric phase and the case of arsenic, its bioaccessibility ranged between 20% and 60%, being equally bioaccessible both in the gastric and gastrointestinal phases. These values are consistent considering fasting in the human system and its high total concentrations present. According to international studies (Wragg, J., Cave, 2012) the RSD is a repeatability variable. For soils studies the RSD is generally higher for studies with soils, even nearing up to 20%. Also, as in this study, it is
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