Hach DR/700 Procedures Manual page 107

NICKEL
(0 to 1.80 mg/L Ni)
For water, wastewater and seawater
Heptoxime Method*; EPA accepted for reporting
(Digestion is required; see Section 1)**
1.
Measure 300 mL
of sample in a 500-mL
graduate cylinder.
Pour into a 500-mL
separatory funnel.
Note: If sample cannot
be analyzed
immediately, see
Sampling and Storage
following these steps.
Adjust the pH of stored
samples before analysis.
Note: For proof of
accuracy, use a 1.0 mg/L
nickel standard solution
(preparation given in
Accuracy Check) in
place of the sample.
*Adapted from Chemie Analytique, 36, 43 (1954).
**Procedure is equivalent to Standard Method 3500-Ni D for wastewater.
2.
Add the contents
of one Nickel 1
Reagent Powder
Pillow to the funnel.
Stopper and shake to
mix.
42-23
Method 8037
5 minutes
3.
Wait 5 minutes.