LaMotte SMART3 Colorimeter - Manual (Page 177)

FLUORIDE
SPADNS METHOD • CODE 3647-02-SC
QUANTITY CONTENTS CODE
4 x 30 mL *Acid Zirconyl SPADNS Reagent *3875-G
2 x 30 mL *Sodium Arsenite Solution *4128-G
1 Pipet, 0.5 mL, plastic 0353
1 Pipet, 1.0 mL, plastic 0354
*WARNING: Reagents marked with an * are considered to be potential health
hazards. To view or print a Material Safety Data Sheet (MSDS) for these reagents
go to www.lamotte.com. To obtain a printed copy, contact LaMotte by e-mail,
phone or fax.
Fluoride may occur naturally in some ground waters or it may be added to
public drinking water supplies to maintain a 1.0 mg/L concentration to prevent
dental cavities. At higher concentrations, fl uoride may produce an objectionable
discoloration of tooth enamel called fl uorosis, though levels up to 8 mg/L have not
been found to be physiologically harmful.
NOTE: This procedure uses the EPA approved Reagent System for fl uoride found
in method 4500-F-D, 18th Edition of Standard Methods, pp. 1-27.
APPLICATION Drinking and surface waters; domestic and industrial
waters.
RANGE: 0.00–2.00 ppm Fluoride
MDL: 0.10 ppm
METHOD: Colorimetric test based upon the reaction between
fl uoride and zirconium dye lake. The fl uoride reacts with
the dye lake, dissociating a portion of it into a colorless
complex ion and dye. As the fl uoride concentration
increases, the color produced becomes progressively
lighter.
Samples may be stored and refrigerated in plastic
containers.
SAMPLE HANDLING
& PRESERVATION:
INTERFERENCES:
The following substances produce a positive interference
at the concentration given:
Chloride (Cl – ) 7000 mg/L
Phosphate (PO
4
–3 ) 16 mg/L
(NaPO
3
)
6
1 mg/L
SMART3 Test Procedures 11.10 FLUORIDE
Test P
rocedures