Materials and methods
2.1. Apparatus
A Perkin–Elmer 1100B double beam atomic absorption spectrometer equipped with a MHS-10 hydride generator (PerkinElmer, Norwalk CT, USA) was used for the Se determination. Argon of 99.999% purity (Spanish Society of Oxygen, Barcelona, Spain) at 300 mL/min was used as carrier gas for Se determination by HG–AAS.