The digested samples were analysed for Hg
contents using a model Analyst 700 atomic absorption spectrometer (Perkin–Elmer,
Norwalk, CT, USA) coupled with a MHS-15 system (Perkin–Elmer). A Hg hollow
cathode lamp operated at 5 mA was utilized as the radiation source. Measurements
were carried out in the integrated absorbance (peak area) mode at 253.7 nm, using
a spectral band width of 2.6 nm. Argon 99.99% was used as the carrier gas.