XXIV
Release 07/03
Instructions for the Preparation of Standard Solutions
Standard solution of total nitrogen
Preparation of a standard solution:
Dissolve 5.36 g of glycine GR with DI water in a
calibrated or conformity-checked 1-l volumetric
flask and make up to the mark. The stock solution
prepared according to this procedure has a
concentration of 1000 mg/l total nitrogen.
Further investigational concentrations may be
prepared from this stock solution by diluting
accordingly.
▼
Stability:
When stored in a cool place (refrigerator), the
stock solution remains stable for one week. The
diluted investigational concentrations must be
used immediately.
▼
Reagents required:
1.04201.0100
Glycine GR
1.16754.9010
Water GR
Standard solution of ozone
acc. to DIN EN ISO 7393
Preparation of a KlO
3
stock solution:
In a 1000-ml volumetric flask dissolve 1.005 g
of KlO
3,
art.1.02404, in 250 ml of distilled water.
Subsequently make up to the mark with distilled
water.
▼
Preparation of a KlO
3
/Kl standard solution:
Transfer 14.8 ml of the KlO
3
stock solution to a
1000-ml volumetric flask, add approx. 1g of Kl,
art. 1.05043, and make up to the mark with
distilled water.
1 ml of this solution is equivalent to 0.010 mg
of ozone.
▼
Preparation of the ozone standard solution:
Pipette 20 ml KlO
3
/Kl standard solution into a
100-ml volumetric flask, add 2.0 ml of H
2
SO
4
0.5 mol/l, art. 1.09072, leave to stand for 1 min,
and then add NaOH 2 mol/l, art. 1.09136,
dropwise (approx. 1 ml) until the solution just
loses its colour. Subsequently make up the
solution to the mark with distilled water.
The concentration of the solution is 2.00 mg/l
ozone.
▼
Stability:
The KlO
3
stock solution remains stable for 4
weeks when stored in a cool place. The KlO
3
/Kl
standard solution can be used for 5 hours when
stored in a cool place. The dilute ozone
standard solution remains stable for a maximum
of 5 minutes.
▼
Reagents required:
1.02404.0100
Potassium iodate, volum. standard
1.05043.0250
Potassium iodide GR
1.09072.1000
Sulfuric acid 0.5 mol/l
1.09136.1000
Sodium hydroxide solution 2 mol/l
Standard solution of phenol
Preparation of a standard solution:
Dissolve 1.00 g of phenol GR with DI water in a
calibrated or conformity-checked 1-l volumetric
flask and make up to the mark. The stock solution
prepared according to this procedure has a
concentration of 1000 mg/l phenol.
Further investigational concentrations may be
prepared from this stock solution by diluting
accordingly.
▼
Stability:
When stored in a cool place (refrigerator), the
stock solution remains stable for one week. The
diluted investigational solutions must be used
immediately.
▼
Reagents required:
1.00206.0250
Phenol GR
1.16754.9010
Water GR
