AQUA LYTIC AL200 Manual De Instrucciones página 37

Methods
GB
Notes:
1. Vial cleaning:
As many household cleaners (e.g. dishwasher detergent) contain reducing substances,
the subsequent determination of Chlorine dioxide may show lower results. To avoid any
measurement errors, only use glassware free of Chlorine demand.
Preparation: Put all applicable glassware into Sodium hypochlorite solution (0.1 g/l) for
one hour, then rinse all glassware thoroughly with deionised water.
2. Preparing the sample:
When preparing the sample, the lost of Chlorinie dioxide, e.g. by pipetting or shaking,
must be avoided. The analysis must take place immediately after taking the sample.
3. The DPD colour development is carried out at a pH value of 6.2 to 6.5. The reagents
therefore contain a buffer for the pH adjustment.
Strong alkaline or acidic water samples must be adjusted between pH 6 and pH 7
before the reagent is added (use 0.5 mol/l Sulfuric acid resp. 1 mol/l Sodium hydroxide).
4. Exceeding the measuring range:
Concentrations above 19 mg/l Chlorine dioxide can lead to results showing 0 mg/l. In
this case, the water sample must be diluted with water free of Chlorine/Chlorine dioxide
and the measurement repeated.
5. Oxidising agents such as Chlorine, Bromine, Ozone etc. interfere as they react in the
same way as Chlorine dioxide.
Tolerances:
0 – 1.9 mg/l: ± 0.1 mg/l
> 1.9 – 3.8 mg/l: ± 0.2 mg/l
> 3.8 – 5.7 mg/l: ± 0.4 mg/l
> 5.7 – 7.6 mg/l: ± 0.6 mg/l
> 7.6 – 11 mg/l: ± 0.8 mg/l
Reagent
DPD No. 1
GLYCINE
AL200_8 03/2018
Form of reagent/Quantity
Tablet / 100
Tablet / 100
Order-No.
4511050BT
4512170BT
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