Preparation Of 4000 Ntu Formazin Stock Solution; Preparation Of Dilutions From The 4000 Ntu Formazin Stock Solution - VWR TIR 200 Manual De Instrucciones

Preparation of 4000 NTU Formazin Stock Solution

In lieu of preparation we recommend using a 4000 NTU Stock Solution that is available from
specialised suppliers because these standards are high quality and you do not have to handle
the raw materials.
84210.180
84211.230
Caution: Please observe the handling instructions of the MSDS. Gloves, goggles and
breathing equipment must be worn!
To prepare a Formazin Stock Solution from raw materials:
1. Dissolve 0.5 g Hydrazine sulfate (NH
2. Dissolve 5.0 g Hexamethylentetramine in 40 ml dilution water.
3. Transfer both solutions quantitativ to a 100 mL volumetric flask and fill to the mark with
dilution water.
4. Mix the solution thoroughly.
5. Allow this solution to stand for at least 24 hours at 25 ± 3°C (77 ± 5°F) in a dark place
(brown glass bottle).
6. The turbidity is developed over this period.
The Formazin Stock Solution has a maximum shelf life of 1 year if stored correctly (in a dark
place). The Production of a Formazin Stock Solution is described in "EN ISO 7027" and
"Standard Methods for Examination of Water and Wastewater".
24696.186
24560.260
Preparation of dilutions from the 4000 NTU Formazin Stock
Solution
To prepare the dilutions from a 4000 NTU Formazin Stock Solution and dilution water:
Standard
20 NTU
200 NTU
VWR ver 1 01/2018
FORMAZIN STOCK SOLUTION (4000 NTU), 100ML
FORMAZIN STOCK SOLUTION (4000 NTU), 250 ML
) H
2 2 2
Hydrazine Sulfate, ACS reagent, 100 g
Methenamine ≥ 99.0% AnalaR NORMAPUR
Step 1
Add 100 ml of dilution
water to a clean
200 ml volumetric flask.
Add 50 ml of dilution
water to a clean
100 ml volumetric flask.
SO in 40 ml dilution water.
4
®
Step 2
Pipette 1.00 ml well
mixed 4000 NTU
Formazin Stock Solution
to this
200 ml flask.
Pipette 5.00 ml well
mixed 4000 NTU
Formazin Stock Solution
to this
100 ml flask.
analytical reagent, 500 g
Step 3
Fill to the mark with
dilution water. Close and
mix the flask.
Fill to the mark with
dilution water. Close and
mix the flask.
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