Hach DR/700 Procedures Manual page 680

PHOSPHONATES,
4.
Choose a sample
size from Table 1
below. Pipet the
chosen sample
volume into a 50-mL
graduate mixing
cylinder. Dilute the
sample to 50 mL with
demineralized water.
Mix well.
Table 1. Sample Volume
Expected Phosphonate
Range (mg/L)
0-2.5
0-5
0-12.5
0-25
0-125
continued
5.
Split the diluted
sample by pouring 25
mL into each of two
sample cells.
Sample Volume
(mL)
50
25
10
5
1
81-6
6.
Add the contents
of one Potassium
Persulfate For
Phosphonate Powder
Pillow to one of the
sample cells (the
prepared sample).
Cap and invert several
times to mix.