Sediment samples were collected using a stainless
steel dredge; approximately 1 kg of the middle
of each sample was put in a polyethylene bag
and stored at 48C during its transport to the
laboratory. Sediments were dried in an oven at
508C for 48 h, then were ground in an agate
mortar, sieved through a 200-mesh sieve and homogenised
in an automatic mixer for 30 min.
EDXRF 50-g samples were prepared by using a
5-ton press, which produced 3.1-cm diameter pellets.
ICP 2-g samples were digested by a three-step