Hach DR/700 Procedures Manual page 421

MANGANESE, HR,
Iron
Magnesium
Highly buffered samples or extreme sample pH may exceed the
buffering capacity of the reagents and require sample pretreatment; see
Interferences, pH (Section I).
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 10.0 mg/L Mn
concentration samples, the standard deviation was ±0.11 mg/L Mn.
Testing zero concentration samples, 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).
SUMMARY OF METHOD
Manganese in the sample is oxidized to the purple permanganate state by
sodium periodate, after buffering the sample with citrate. The purple color
is directly proportional to the manganese concentration. If only dissolved
manganese is to be determined, filter the sample before acid addition.
REQUIRED REAGENTS
Description
Buffer Powder Pillows, citrate type
for manganese, 10 mL . . . . . 1 pillow . . . . 50/pkg . . . . . . . . . 21076-69
Sodium Periodate Powder Pillows
for manganese, 10 mL . . . . 1 pillow . . . . 100/pkg . . . . . . . 21077-69
REQUIRED APPARATUS
Clippers, for opening
powder pillows . . . . . . . . . . 1 . . . . . . . . . each . . . . . . . . . . . 968-00
DR/700 Filter Module
Number 52.01. . . . . . . . . . . 1 . . . . . . . . . each . . . . . . . . . . 46252-00
OPTIONAL REAGENTS
Buffer Powder Pillows, Citrate,
25 mL (for manganese) . . . . . . . . . . . . . . 100/pkg . . . . . . . . 983-99
Hydrochloric Acid, 6N . . . . . . . . . . . . . . . . . 500 mL . . . . . . . . 884-49
continued
5 mg/L
100,000 mg/L
Quantity
Per Test Unit
52-95
Cat. No.