Hach DR/700 Procedures Manual page 89

BENZOTRIAZOLE AND TOLYLTRIAZOLE,
b) Analyze according to the above procedure. If the result is
significantly below 5.0 mg/L, replace the lamp.
STATISTICAL EVALUATION
A single operator repetitively tested samples of two laboratory prepared
solutions, using one DR/700, matched sample cells and two
representative lots of reagent. Testing 10.0 mg/L tolyltriazole
concentration solutions, the standard deviation was ±0.22 mg/L
tolyltriazole. Testing zero concentration samples, the limit of detection
was 0.17 mg/L tolyltriazole.
Testing 10.0 mg/L benzotriazole concentration solutions, the standard
deviation was ±0.11 mg/L benzotriazole. Testing zero concentration
samples, the limit of detection was 0.16 mg/L benzotriazole.
The limit of detection was calculated as three times the standard
deviation when testing zero concentration samples (adapted from
Analytical Chemistry, 1980, 52, 2242-2249).
INTERFERENCES
The following may interfere when present in concentrations exceeding
those listed below:
Acrylates (as methyl acrylate)
Alum
Borate (as sodium tetraborate)
Chlorine (as Cl )
2
Chromium (as chromate)
Copper
Hardness
Iron
Lignosulfonates
Magnesium
Molybdenum (as molybdate)
Nitrite
Phosphonates (AMP or HEDP)
Sulfate
Zinc
Strong oxidizing or reducing agents present in the sample will interfere
directly.
50 mg/L
400 mg/L
4000 mg/L
20 mg/L
12 mg/L
10 mg/L
500 mg/L as CaCO
20 mg/L
40 mg/L
300 mg/L as CaCO
200 mg/L
4000 mg/L
100 mg/L
200 mg/L
80 mg/L
42-5
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