Collect water samples to be tested.
Prepare nitrate standards containing 2
mg/L, 5 mg/L and 10 mg/L nitrate ions, from the stock
Prepare a reagent blank. Distilled water
will be acceptable for this.
Set the UV-Visible spectrophotometer to
read at 220 nm.
Prepare a silica sample cell.
Measure the absorbance value for the reagent
blank; record this value in your Log Book.
Measure the absorbance for the 2 mg/L,
5 mg/L and 10 mg/L nitrate standard solutions. Record
these values in your Log Book.
Measure the absorbance of the water samples.
Enter the data from your analysis into
the laboratory computer spread sheet. The computer will
calculate the concentration of nitrate in the samples
using the data entries.
Record the concentration
of nitrate in the water samples in your Log Book, and
on the Laboratory Test Sheet.