Fluoride – LaMotte SMART3 Colorimeter User 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

Pipet, 0.5 mL, plastic

0353

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

–3

) 16 mg/L

(NaPO

)

1 mg/L

SMART3 Test Procedures 11.10

FLUORIDE

Test P

rocedures