3.4. Effect of standing time
The effect of time on the reaction of iodide–nitrite was studied.
100 ng mL
−1
of the nitrite, 8 mL of Triton X-100 (5%), 5.5 mL of
0.02 mol L
−1
iodide and 3 mL of 0.1 mol L
−1
sulfuric acid were added
to a 25 mL volumetricflask, made up to the mark with water and left to
stand for different time intervals. The results of this investigation are
presented inFig. 4. As it is observed the absorbance and hence the cloud
point extraction efficiency are increased by increasing the standing time
for the completion of the reaction at up to 30 min and remained
constant after that. Thus, 30 min standing time was chosen for the
completion of the reaction