Chlorine dioxide – LaMotte DC1600 Colorimeter User Manual
Page 23
CHLORINE DIOXIDE
DPD METHOD
CODE 3644
QUANTITY
CONTENTS
CODE
100
*DPD #1 Instrument GradeTablets
*6903-J
15 mL
Glycine Solution
6811-E
1
Tablet Crusher
0175
*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.
Chlorine dioxide is used as a substitute for and an adjunct to chlorine in water treatment. It is better than chlorine in
eliminating taste and odor in certain cases. Chlorine dioxide, unlike chlorine, does not produce carcinogenic chlorinated
organic compounds when reacted with organic materials. A disadvantage is the higher cost of producing chlorine dioxide
compared to chlorine.
APPLICATION:
Drinking and pool waters; domestic and industrial wastewater.
RANGE:
0 – 7.0 ppm Chlorine Dioxide
METHOD:
Chlorine dioxide reacts with DPD to form a red color in proportion to the concentration.
SAMPLE HANDLING
& PRESERVATION:
Test as soon as possible to avoid loss of chlorine dioxide.
INTERFERENCE:
Chlorine interference is eliminated by the addition of glycine to the sample before the
indicator.
PROCEDURE
1.
Rinse a clean colorimeter tube (0967) with sample water. Fill to 10 mL line with sample.
2.
Select setting 4 on “Select Wavelength” knob and press “30 Second Read” button.
3.
Insert tube into colorimeter chamber and adjust to 100%T with “Set Blank” knob. This tube is the 100%T blank.
4.
Remove tube from colorimeter. Pour out all but a sufficient amount of sample water to cover tablet. Add 5 drops of
Glycine Solution (6811).
5.
Add one *DPD #1 Instrument Grade Tablet (6903). Crush tablet with tablet crusher. Cap and shake until tablet
dissolves. Fill to 10 mL line with sample water. Solution will turn pink if chlorine dioxide is present.
6.
Press “30 Second Read” button and insert tube into colorimeter chamber. Record %T as soon as reading stabilizes.
The reading should be made within 30 seconds.
7.
Consult calibration chart to determine chlorine dioxide concentration in parts per million (ppm).
DC1600 CHLORINE DIOXIDE CALIBRATION CHART
%T
9
8
7
6
5
4
3
2
1
0
90
0.00
0.02
0.03
0.05
0.07
0.09
0.11
0.12
0.14
80
0.16
0.18
0.20
0.22
0.24
0.26
0.28
0.30
0.32
0.35
70
0.37
0.39
0.41
0.44
0.46
0.48
0.51
0.53
0.56
0.59
60
0.61
0.64
0.67
0.70
0.72
0.75
0.78
0.81
0.85
0.88
50
0.91
0.94
0.98
1.01
1.05
1.08
1.12
1.16
1.20
1.24
40
1.28
1.32
1.37
1.41
1.46
1.51
1.55
1.61
1.66
1.71
30
1.77
1.82
1.88
1.94
2.01
2.07
2.14
2.21
2.29
2.36
20
2.44
2.53
2.61
2.70
2.80
2.90
3.01
3.12
3.24
3.37
10
3.50
3.64
3.79
3.96
4.14
4.33
4.54
4.77
5.02
5.31
0
5.63
6.00
6.42
6.93
23