Hach DR/700 Procedures Manual page 496

MANGANESE, LR,
d) If these increases do not occur, see Standard Additions (Section I) for
more information.
Standard Solution Method
Prepare a 0.5 mg/L manganese standard solution as follows:
a) Pipet 5.00 mL of Manganese Standard Solution, 1000 mg/L Mn, into
a 1000-mL volumetric flask.
b) Dilute to the mark with demineralized water. This solution should be
prepared daily.
c) Pipet 10 mL of the above dilution into a 100-mL volumetric flask.
d) Dilute to the mark with demineralized water. This second dilution is
equivalent to 0.5 mg/L Mn.
e) Perform the manganese procedure as described above. The reading in
Step 12 should be 0.5 mg/L Mn.
STATISTICAL EVALUATION
A single operator repetitively tested samples of two laboratory prepared
solutions, using one DR/700, matched sample cells and two
representative lots of testing reagents. Testing 0.500 mg/L Mn
concentration samples, the standard deviation was ±0.0029 mg/L Mn.
Testing zero concentration samples, the limit of detection was
0.0022 mg/L Mn. The limit of detection was calculated as three times
the standard deviation when testing zero concentration samples
(Adapted from Analytical Chemistry, 1980, 52, 2242-2249)
INTERFERENCES
The following do not interfere up to the indicated concentrations:
Aluminum
Cadmium
Calcium
Cobalt
Copper
Iron
Lead
continued
20 mg/L
10 mg/L
1000 mg/L as CaCO
20 mg/L
50 mg/L
25 mg/L
0.5 mg/L
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