The mixture of sample and HCl solution is introduced through the bottom of
MSIS, at which occurs the reaction with 10% (w v−1) SnCl2 solution to
generate mercury vapor that is carried to the torch formed by nitrogen.
The third channel was used to discharge the residual solutions from the
MSIS. Tables 1 and 2 present the operating conditions for each equipment.
The instruments were operated under the conditions recommended
by the respective manufacturers. The MSIS spray chamber
was pre-conditioned for 15 s (stabilization time in Table 2) using the
acid and reducing agent solutions (washing step) before the next sample
introduction. The analytical frequency was around 80 samples per
hour.