Silica
, Low Range
COD3 Plus Colorimeter 10.16
APPLICATION:
Drinking, surface and saline waters; domestic and
industrial wastes.
RANGE:
0.0–4.0 ppm Silica
MDL:
0.05 ppm
METHOD:
Reactive silica forms a complex with ammonium molybdate
in an acidic solution to produce a yellow-green color in
proportion to the amount of silica present. Phosphate
also reacts with molybdate but the addition of oxalic acid
eliminates the molybdophosphoric acid complex. This silica
molybdate complex is then reduced by ascorbic acid to
produce an intense blue color.
SAMPLE HANDLING &
PRESERVATION:
Silica samples may be preserved by refrigeration at 4°C in
plastic containers up to one week without any change in
silica concentration.
INTERFERENCES:
Sulfi des and large amounts of iron interfere. Color and
turbidity may be removed by standardizing the instrument
with the original water sample. Since silica is a component
of glass waste and a common contaminant, it is suggested
to run a reagent blank using silica-free water. The blank
value is subtracted from the sample concentrations.
Testing
Содержание COD3 Plus
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Страница 38: ...Ammonia Nitrogen Low Range COD3 Plus Colorimeter 10 16 Testing ...
Страница 42: ...Ammonia Nitrogen High Range COD3 Plus Colorimeter 10 16 Testing ...
Страница 46: ...Boron COD3 Plus Colorimeter 10 16 Testing ...
Страница 72: ...Dissolved Oxygen COD3 Plus Colorimeter 10 16 Testing ...
Страница 76: ...Fluoride COD3 Plus Colorimeter 10 16 Testing ...
Страница 90: ...Phosphate Low Range COD3 Plus Colorimeter 10 16 Testing ...
Страница 98: ...Silica Low Range COD3 Plus Colorimeter 10 16 Testing ...
Страница 102: ...Silica High Range COD3 Plus Colorimeter 10 16 Testing ...
Страница 108: ...Testing Sulfide Low Range COD3 Plus Colorimeter 10 16 ...
Страница 114: ...Testing Turbidity COD3 Plus Colorimeter 10 16 ...