Annexes
B. Sodium salicylate solution (1 liter)
Required chemicals: Sodium hydroxide .......... 25 g.
NaOH
Sodium salicylate ........... 80 g.
C7H5NaO3
Distilled water
H2O
Preparation: Dissolve the sodium hydroxide in ± 50 ml
distilled water. Add ± 800 ml distilled water. Add the
sodium salicylate. Fill up to 1 liter with distilled water and
mix.
Note: Store in a dark coloured bottle. Solution is
stable for 1 week. Store at 4°C when the solution is not
used.
C. Sodium nitroprusside solution (1 liter)
Required chemicals: Sodium nitroprusside .... 1.0 g.
Na2[Fe(CN)5NO].2H2O
Distilled water
H2O
Preparation: Dissolve the sodium nitroprusside in ± 800
ml distilled water. Fill up to 1 liter with distilled water and
mix.
Note: Store in a dark coloured bottle. Solution is
stable for 1 week. Store at 4°C when the solution is not
used.
D. Dichloroisocyanuric acid sodium salt
(1 liter) Required chemicals: Dichloroisocyanuric acid
sodium salt.................... 2.0 g.
C3N3O3Cl2Na.2H2O
Distilled water
H2O
Preparation: Dissolve the dichloroisocyanuric acid
sodium salt in ± 800 ml distilled water. Fill up to 1 liter
with distilled water and mix.
Note: Solution is stable for 1 week. Store at 4°C
when the solution is not used.
E. Distilled water
Required chemicals: Distilled water
H2O
Note: Refresh weekly.
F. Rinsing liquid sampler
Required chemicals: Distilled water
H2O.
STANDARDS
Stock solution 100 mg N/liter (1 liter)
Required chemicals: Ammonium
chloride .................. 381.9 mg.
NH4Cl
Distilled water H2O
Note: For sea water samples, adjust the salinity of the
rinsing water sampler to the same level as the salinity of
the sea water samples when matrix peaks reach the same
level as the detection limit. Use ultra pure sodium chloride
or “zero” seawater for adjustment.
Refresh weekly.
Preparation: Dissolve the ammonium chloride in ± 800
ml distilled water. Fill up to 1 liter with distilled water
and mix.
Note: Solution is stable for 1 month. Store at 4°C when
the solution is not used.
3.2. Ammonium
REAGENTS
A. Buffer solution (1 liter)
Required chemicals: Potassium sodium
tartrate........................... 33 g.
C4H4O6KNa.4H2O
tri-Sodium citrate ........... 24 g.
C6H5O7Na3.2H2O
Distilled water
H2O
Brij 35 (30%)................... 3 ml.
Preparation: Dissolve the potassium sodium tartrate in ±
800 ml distilled water. Add the tri-sodium citrate and
dissolve. Fill up to 1 liter with distilled water, add the Brij
35 and mix.
Note: Check the pH and adjust if necessary with
hydrochloric acid to 5.2 ± 0.1. Solution is stable for 1
week. Store at 4°C when the solution is not used.