Standard Methods: 4500-SO42- C:  Sulfate by Gravimetric Analysis with Ignition of Residue

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  • Analytes
  • Revisions
  • Data and Sites
Official Method Name
Gravimetric Analysis with Ignition of Residue
Current Revision
Standard Methods Online
Media
WATER
Instrumentation
Gravimetry
Method Subcategory
Inorganic
Method Source
  Standard Methods
Citation
  Standard Methods Online - Standard Methods for the Examination of Water and Wastewater
Brief Method Summary
Sulfate is precipitated in an HCl solution as barium sulfate by the addition of barium chloride. The precipitation is carried out near the boiling temperatutre, and after a period of digestion, the precipiate is filtered, washed with water until free of chloride, ignited or dried, and weighed as barium sulfate.
Scope and Application
This method determines sulfate in water.
Applicable Concentration Range
>10 mg/L
Interferences
(A) High results: High results can be caused by suspended matter, silica, BaCl2 precipitant, nitrate, sulfite, and occluded mother liquor in the precipitate.
(B) Low results: Low results can be caused by alkali metal sulfates, particularly alkali hydrogen sulfates.
Quality Control Requirements
General quality control procedures are provided in Section 4020 of Standard Methods.
Sample Handling
Refrigerate.
Maximum Holding Time
28 days.
Relative Cost
Less than $50
Sample Preparation Methods