2.5 Determination of total iron by atomic absorption spectroscopy
Dissolved total iron concentration was measured by flame Atomic Absorption Spectroscopy (AAS) Shimadzu AA-7000 equipped with a graphitic oven, at λ = 248.3 ± 0.2 nm (LoQ = 0.027 μg L-1). Aliquots of 25 mL were filtered (membranes of 0.22 μm) and further acidified (pH 2.0) for further analysis.