All measurements were carried out with a Varian Spectr AA–Zeeman 220 graphite furnace atomic absorption spectrometer (Springvale, Australia) equipped with a GTA 110 graphite furnace and an automatic autosampler
All measurements were carried out with a Varian SpectrAA–Zeeman 220 graphite furnace atomic absorption spectrometer(Springvale, Australia) equipped with a GTA 110 graphite furnaceand an automatic autosampler