Nickel
Nickel
Nickel_PP_Other_PAN_Eng_Ody.fm Page 3 of 6
Interferences
Sample Collection, Storage and Preservation
Collect samples in acid-washed plastic bottles. Adjust the sample pH to 2 or less
with Nitric Acid (Cat. No. 2540-49), about 5 mL per liter. Preserved samples can
be stored up to six months at room temperature. Before analysis, adjust the
sample pH to between 3 and 8 with 5.0 N Sodium Hydroxide Standard Solution
(Cat. No. 2450-32). If the sample is less than 10 °C, warm it to room temperature.
Do not exceed pH 8 as this may cause some loss of nickel as a precipitate. Correct
test results for volume additions, see Section 3.1.3 Correcting for Volume Additions
on page 29.
Accuracy Check
Standard Additions Method (Sample Spike)
1. After reading test results, leave the sample cell (unspiked sample) in the
instrument.
2. Touch
Options. Touch Standard Additions. A summary of the standard
additions procedure will appear.
3. Touch
OK to accept the default values for standard concentration, sample
volume, and spike volumes. Touch
Edit to change these values. After values
are accepted, the unspiked sample reading will appear in the top row. See
Standard Additions in the instrument manual for more information.
Interfering Substance Interference Levels and Treatments
Al
3+
32 mg/L
Ca
2+
1000 mg/L as (CaCO
3
)
Cd
2+
20 mg/L
Cl
–
8000 mg/L
Chelating agents
Interfere at all levels. Use either the Digesdahl or vigorous digestion to eliminate this interference
(see Section 2).
Cr
3+
20 mg/L
Cr
6+
40 mg/L
Cu
2+
15 mg/L
F
–
20 mg/L
Fe
3+
10 mg/L
Fe
2+
Interferes directly and must not be present.
K
+
500 mg/L
Mg
2+
400 mg/L
Mn
2+
25 mg/L
Mo
6+
60 mg/L
Na
+
5000 mg/L
Pb
2+
20 mg/L
Zn
2+
30 mg/L
Highly buffered samples or
extreme sample pH
May exceed the buffering capacity of the reagents and require sample pretreatment; see
Section 3.3 Interferences on page 41.
To Next Page
Loading...
