50ml sample was placed in a 500 ml refluxing flask. 5 to 7 glass boiling beads was added to serve as antibumping
aid followed by the addition of 1g of mercury (II) tetraoxosulphate (VI) (HgSO4) crystal. 5 ml of
concentrated tetraoxosulphate (VI) acid (H2SO4)/silver (I) tetraoxosulphate (VI) solution (Ag2SO4) was added,
and mix until the HgSO4 was in solution. The function of HgSO4 is to bind or complex chlorides. 1 g may not be
required if the chloride concentration is low (Caution: Always add acid slowly down the side of the flask while
mixing to avoid over-heating. It may be necessary to use gloves because of the heat generated).