Following the sample preparation step described by the official
method proposed by ANDA for mercury determination in fertilizers, a
sample mass of 2.0 g (the official method recommends a sample mass
from 1 to 2 g) was transferred to a 250 mL Erlenmeyer followed by
the addition of 5 mL deionized water and 5 mL aqua regia to extract
the analyte.