The grains from the Guayas province yielded the highest tAs concentrations
(0.125 ± 0.044 mg kg−1 d.w.) which was significantly higher than the concentrations in field rice from the Los Ríos province (0.042 ± 0.040 mg kg−1 d.w.) and market rice (0.067 ± 0.029 mg kg−1 d.w.) (Table 3). An abnormally high concentration was detected in the samples from Taura (Guayas province), especially in the stems and leaves (Taura, field rice: 0.139 ± 0.04 mg kg−1 d.w.; leaf: 0.665 ± 0.275 mg kg−1 d.w.; stem: 0.506 ± 0.251 mg kg−1 d.w.; n = 4).