LaMotte SMART 2 - Manual (Page 155)

FLUORIDE
SPADNS METHOD • CODE 3647-01-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, fluoride may produce an
objectionable discoloration of tooth enamel called fluorosis, though levels up
to 8 mg/L have not been found to be physiologically harmful.
þ NOTE: This procedure uses the EPA approved Reagent System for fluoride
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 Fluoride
METHOD: Colorimetric test based upon the reaction between fluoride
and zirconium dye lake. The fluoride reacts with the dye
lake, dissociating a portion of it into a colorless complex ion
and dye. As the fluoride concentration increases, the color
produced becomes progressively lighter.
SAMPLE
HANDLING &
PRESERVATION: Samples may be stored and refrigerated in plastic containers.
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
Smart2 TEST PROCEDURES 2.04 Fluoride 1/3