EPA-NERL: 215.2:  Calcium by Titrimetry

  • Summary
  • Analytes
  • Revision
  • Data and Sites
Official Method Name
Calcium (Titrimetric, EDTA)
Current Revision
Issued 1974; Editorial Revision 1978
Media
WATER
Instrumentation
Titration
Method Subcategory
Inorganic
Method Source
  EPA-NERL
Citation
  Methods for the Chemical Analysis of Water and Wastes (MCAWW) (EPA/600/4-79/020)
Brief Method Summary
Calcium ion is sequestered upon the addition of disodium dihydrogen ethylenediamine tetraacetate (EDTA). The titration end point is detected by means of an indicator which combines with calcium only.
Scope and Application
This method determines calcium in drinking and surface waters, domestic and industrial wastes.
Applicable Concentration Range
0.5-25 mg/L as Ca(CO)3.
Interferences
Metals: Strontium and barium interfere in excess of 30 mg/L and may cause an indistinct end point. Magnesium can also interfere, but is eliminated by raising the pH to 12-13 to precipitate magnesium hydroxide.
Quality Control Requirements
None.
Sample Handling
None.
Maximum Holding Time
6 months (MCAWW, Table 1).
Relative Cost
Less than $50
Sample Preparation Methods
None.