5
V.
V.
V.
V.
V. Equipment required:
Equipment required:
Equipment required:
Equipment required:
Equipment required:
•
Hanna HI 5315 Double Junction Reference Electrode
with HI 7072 Fill Solution for HI 4012.
•
Hanna HI 4222 pH/ISE/mV meter or other suitable
ion or pH/mV meter. (Note: log/linear graph paper is
useful if an ISE (ion) meter is not available).
•
Hanna HI 180 Magnetic Stirrer or equivalent with TFE
coated stirring bars (HI 731320). Note: isolate bea-
kers from stirrer motor heat by placing insulating
material such as foam or cork between them.
•
Hanna HI 76404 Electrode Holder or equivalent.
•
Plastic beakers (HI 740036P) or other suitable mea-
surement vessel.
VI.
VI.
VI.
VI.
VI. Solutions Required
Solutions Required
Solutions Required
Solutions Required
Solutions Required
For Lead Measurements
0.1 M lead standard, (500 mL)
HI 4012-01
ISA, (5 X 100 mL)
HI 4012-00
For Sulfate Titrations
(used to standardize lead perchlorate solutions)
0.1 M sulfate standard, (500 mL)
HI 4012-21
See Section XII ; Titrations
User supplied solutions:
A user supplied Methanol/Formalin solution is required to
decrease pellet solubility and oxidative effects. To prepare,
add 200
µ
L 37 wt. % formalin in H
2
O to 500 mL of
reagent grade methanol. Stir and store in tightly closed
glass bottle. This solution is used at a dose of 50 parts of
the Methanol/Formalin solution to 50 parts standard or
sample.
For Direct lead measurements- Using volumetric pipettes
and glassware, make dilutions of HI 4012-01 to bracket
the concentration of the samples. Note: 0.1M lead stan-
dard is equivalent to 20,720 ppm. Standards with con-
centrations
<
10
-3
M (207ppm) should be prepared daily.
Store in tightly closed plastic bottle. To 50 parts standard or
sample add 50 parts Methanol/Formalin solution plus 2
mL of ISA.