YSI pHotoFlex Series - Manual (Page 22)

22 ba76126e01 03/2013
Note: Before using the test with your photometer for the first time, determine the reagent blank
value.
YSI model no.: NH4-2 TC (LR)
Category: KT (reaction cell test)
Cell: 16 mm
Measuring range: 0.02 - 2.50 mg/l NH
4
-N
0.03 - 3.20 mg/l NH
4
Display in mmol/l possible
Check the pH value of
the sample.
Desired value: approx.
pH 7.
Correct with diluted
sodium hydroxide
solution or hydrochloric
acid as necessary. Pipette 2.0 ml of sample
into a reaction cell. Add the contents of a
VARIO AMMONIA
Salicylate F5 powder
pack. Add the contents of a
VARIO AMMONIA
Cyanurate F5 powder
pack and close the cell
with the screw cap. Shake the cell vigorously
to dissolve solids.
Allow to react for 20
minutes. Insert the cell in the
photometer cell shaft
and start measurement.
Notes:
• We recommend to determine a new reagent blank value (deionized water instead of sample) for each test package started.
• If NH
4
-N is present in the sample, the solution becomes green after VARIO AMMONIA Cyanurate F5 was added.
• If chlorine is present, sodium thiosulfate has to be added to the sample immediately after sampling. Add 1 drop of a 0.1
mol/l sodium thiosulfate solution per 0.3 mg/l chlorine to 1 liter sample.
• Iron disturbs the measurement and can be eliminated as follows: Determine the total iron concentration and prepare an
iron standard solution with the determined concentration. Use this solution instead of distilled water to determine the
reagent blank value for ammonium measurement.
approx.
pH 7
20:00
Ammonium vario LR
Program no.
312
*RN312*