In common with Method 14G2a, F– and other anions, including Cl–, SO4-S, NO3-N and PO4-P, are included in this analytical suite, described in more detail in Methods 5A3b and 14E2b. The method has high sensitivity (see APHA-AWWA-WEF 2005d) so is suitable for F– determinations, provided high-quality reagents are used. Minimum detectable concentrations of anions are ≈0.02–0.12 mg/L with an injection volume of 100 μL, although detection levels can be reduced by increasing the injection volume. Alternative IC technology, based on chemical suppression of eluent conductivity, is provided as Method 14G2a.
As for Method 5A3b and Method 14E2b.
Fluoride Primary Standard
1 L contains 1000 mg of F.
As for Method 14G2a.
Analyse an aliquot of the SE (no particles >0.20 μm) by IC (single-column with electronic suppression of eluent conductivity) as outlined in Method 14E2b.
Report F–/SE (mg/L) with relevant method codes, or divide by 18.998 to convert to cmolcF/L.