EPA-NERL: 340.2:  Fluoride by ISE

  • Summary
  • Analytes
  • Revision
  • Data and Sites
Official Method Name
 Fluoride (Potentiometric, Ion Selective Electrode)
Current Revision
Issued 1971; Editorial Revision 1974
Media
 WATER
Instrumentation
 Ion Selective Electrode
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
 Fluoride is determined potentiometrically using a fluoride electrode in conjunction with a standard single junction sleeve-type reference electrode and a pH meter having an expanded millivolt scale or a selective ion meter having a direct concentration scale for fluoride.
Scope and Application
 This method determines fluoride in drinking, surface, and salin waters; domestic and industrial wastes.
Applicable Concentration Range
 0.1 - 1,000 mg/L
Interferences
 (A) Extreme pH: Extreme pH interferes. pH should be between 5-9.
Polyvalent cations: Polyvalent cations of Si4+, Fe3+, and Al3+ interfere by forming complexes with fluoride.
A pH 5.0 buffer with a strong chelating agent eliminates interferences.
Quality Control Requirements
 None.
Sample Handling
 No special requirements.
Maximum Holding Time
 28 days (MCAWW, Table 1).
Relative Cost
 Less than $50
Sample Preparation Methods
WHO WE ARE
  • NWQMC
  • USGS
  • EPA
LEGAL