| Possible
coexisting substances and their interferences |
Substance
|
Concentration
|
Interference |
Change
color by itself |
CN-
|
20mg/l or lower
|
Plus error
|
Discolor white
stain at 1 mg/l or higher |
Br-
|
10 mg/l or higher
|
Plus error
|
Discolor white
stain at 10 mg/l or higher |
SCN-
|
1 mg/l or higher
|
Cannot read
|
Discolors white
stain at 100mg/l or higher |
Fe2+
|
20 mg/l or higher
|
Minus error |
No effect less
than 1000 mg/l or below |
Fe3+
|
20mg/l or higher
|
Plus error |
Discolor white
stain at 20 mg/l or higher |
F-
|
1000 mg/l or lower
|
No effect |
No effect less
than 1000 mg/l |
I-
|
20 mg/l or higher
|
Plus error |
Discolors pale
yellow higher than 20mg/l |
S2-
|
3 mg/l or higher
|
Plus error |
Discolors blackish
gray 3 mg/l or higher |
SO42-
|
1000 mg/l or higher
|
No effect |
No stain at 1000
mg/l or lower |
