Hach Co.: 8221: Alkalinity by Buret Titration
|
Official Method Name
|
Alkalinity Determination By Buret Titration |
|---|---|
|
Current Revision
| 2003 |
|
Media
|
WATER |
|
Instrumentation
|
Titration |
|
Method Subcategory
|
Inorganic |
|
Method Source
|
|
|
Citation
|
|
|
Brief Method Summary
|
Alkalinity is expressed as P (phenolphthalein) alkalinity or as T (total) alkalinity. Both types are determined by titration with a sulfuric acid standard solution to an end point evidenced by the color change of an indicator solution or determined with a pH meter. The P alkalinity is determined by titration to a pH of 8.3 and registers the total hydroxide and one half the carbonate present. The T alkalinity is determined by titration to a pH of 4.5. The total alkalinity includes all carbonate, bicarbonate and hydroxide alkalinity. Alternatively, total alkalinity end points may be determined by using a pH meter and titrating to the specific pH required for the sample composition. |
|
Scope and Application
|
For water, wastewater, and seawater |
|
Applicable Concentration Range
|
0-5000 mg/L as CaCO3 |
|
Interferences
|
Chlorine at levels above 3.5 mg/L cause a yellow-brown color upon the addition of the Bromcresol Green-Methyl red indicator. Highly colored or turbid samples may mask the color change at the end point. |
|
Quality Control Requirements
|
|
|
Sample Handling
|
Collect samples in clean plastic or glass bottles. Fill completely and cap tightly. Avoid agitation and prolonged exposure to air. Samples should be analyzed as soon as possible after collection. |
|
Maximum Holding Time
|
|
|
Relative Cost
|
Less than $50 |
|
Sample Preparation Methods
|
