Arsenic
Arsenic
Arsenic_None_Other_SDC_Eng_Ody.fm Page 3 of 6
Interferences
Sample Collection, Storage and Preservation
Collect samples in acid washed glass or plastic bottles. Adjust the pH to 2 or less
with sulfuric acid (about 2 mL per liter) (Cat. No. 1270-32). Preserved samples
may be stored up to six months at room temperature. Correct the test result for
volume additions; see Section 3.1.3 Correcting for Volume Additions on page 29.
17. Touch the timer icon.
Touch
OK.
A third 15-minute reaction
period will begin.
18. When the timer
beeps, turn off the heater.
Remove the cylinder/gas
bubbler assembly as a
unit.
19. Rinse the gas bubbler
by moving it up and
down in the arsenic
absorber solution.
20. Fill a dry, 25-mL
sample cell with
untreated arsenic
absorber solution (the
blank). Stopper.
21. Wipe the blank and
place it into the cell
holder.
22. Touch Zero.
The display will show the
intercept as calculated
from your user-entered
calibration curve. This
will probably be a non-
zero intercept.
23. Pour the reacted
arsenic absorber sample
into a sample cell. If the
solution volume is less
than 25 mL, add pyridine
to bring the volume to
exactly 25 mL. Stopper.
24. Wipe the prepared
sample and place it into
the cell holder.
Touch
Read.
Interfering Substance Interference Levels and Treatments
Antimony Salts May interfere with color development.
10 mL
20 mL
25 mL
10 mL
20 mL
25 mL
Zero
10 mL
20 mL
25 mL
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