NEMI Method Summary


Method Summary Information

Method Number:

340.2

Media:

WATER

Revision:

Issued 1971; Editorial Revision 1974

Method Source:

U.S. EPA National Exposure Research Laboratory (NERL) [formerly EMSL]

Analytes in this method

Subcategory:

INORGANIC

Official Name:

Fluoride (Potentiometric, Ion Selective Electrode)

Descriptive Name

Fluoride by ISE

Source Info:

U.S.EPA National Exposure Research Laboratory (NERL)
Microbiological and Chemical Exposure Assessment Research Division (MCEARD)
[formerly the Environmental Monitoring Systems Laboratory (EMSL), Cincinnati, OH]
26 West Martin Luther King Drive
Cincinnati, Ohio 45268-0001
Fax: 513-569-7757
email: DWmethods.help@epa.gov

Citation:

Methods for the Chemical Analysis of Water and Wastes (MCAWW) (EPA/600/4-79/020)

15005

Byte file

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
Conc 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.

QC Requirements:

None.

Sample Handling:

No special requirements.

Max Holding Time:

28 days (MCAWW, Table 1).

Relative Cost:

Less than $50

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Method Summary Information