Chloramine (Mono)
Chloramine (Mono)
Chloramine (Mono)_AVPP_High_MCF_Eng_Ody.fm Page 3 of 6
Sampling and Storage
Analyze samples for monochloramine immediately after collection. Rinse the
sample container several times with sample, letting the container overflow each
time. If sampling from a tap, let the water flow for at least 5 minutes. Then cap
the container so that there is no head space (air) above the sample.
Accuracy Check
To check test accuracy, prepare the following 4.5-mg/L (as Cl
2
) monochloramine
standard immediately before use.
1. Add the contents of one Buffer Powder Pillow, pH 8.3 to about 50-mL of
organic-free water in a clean 100-mL Class A volumetric flask. Swirl to
dissolve the powder.
2. Using a Class A volumetric pipet, transfer 2.00 mL of Nitrogen, Ammonia
Standard Solution, 100-mg/L as NH
3
–N into the flask.
3. Dilute to volume with organic-free water, cap and mix thoroughly. This is a
2.00-mg/L buffered ammonia standard.
4. Pipet 50.00 mL of the buffered ammonia standard into a clean 100-mL beaker.
Add a stir bar.
5. Obtain a recent lot of Chlorine Solution Ampules, 50–70 mg/L, and note the
actual free chlorine concentration for this lot.
6. Calculate the amount of Chlorine Solution to be added to the ammonia
standard using the following equation:
Nitrate 100 mg/L N
Nitrite 50 mg/L N
Phosphate 100 mg/L PO
4
Silica 100 mg/L SiO
2
Sulfate 2600 mg/L
Sulfite 50 mg/L SO
3
2–
Tyrosine 1 mg/L N
Urea 10 mg/L N
Zinc 5 mg/L
Table 1 Non-interfering Substances (continued)
Substance Maximum Level Tested
Table 2 Interfering Substances and Suggested Treatments
Interfering Substance
and its effect
Interference Level
Recommended
Treatment
Ozone – Above 1 mg/L
Usually doesn’t coexist with
monochloramine.
Sulfide +
Turns a “rust” color
if present.
Usually doesn’t coexist with
monochloramine.
Thiocyanate – Above 0.5 mg/L This method will tolerate up to 2 mg/L.
mL chlorine solution required
455
free chlorine concentration
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