LaMotte COD Plus Colorimeter 1922-EX2 - Manual (Page 90)

FLUORIDE
SPADNS METHOD • CODE 3647-SC-01
QUANTITY CONTENTS CODE
4 x 30 mL *Acid-Zirconyl-SPADNS Reagent
*3875-G
60 mL *Sodium Arsenite Solution
*4128-H
1 Pipet, 0.5 mL, plastic
0353
1 Pipet, 1.0 mL, plastic
0354
*WARNING: Reagents marked with a * are considered hazardous substances. Material
Safety Data Sheets (MSDS) are supplied for these reagents. For your safety, read label
and accompanying MSDS before using.
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.
NOTE: This procedure uses the EPA approved Reagent System for fluoride
found in method 4500-F-D, 18th Edition of Standard Methods, page 1-27.
APPLICATION Drinking and surface waters; domestic and industrial waters.
RANGE: 0.00 – 2.00 ppm 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.
COD PLUS TEST PROCEDURES 6/02 FLUORIDE 1/3