Processing kodak motion picture films, module 3 analytical procedures

SPECIAL APPARATUS
Exhaust Hood
Metrohm Potentiograph E536 Titrator or equivalent with
Dosimat with a 20-mL buret
Reference Electrode, Double Junction, Orion No. 900200
or equivalent [Filling solutions: Sat. Silver Chloride
solution, or Orion No. 900002 (inner chamber) and
10 percent potassium nitrate, or Orion No. 900003 (outer
chamber)]
Indicator Electrode, Platinum Inlay/Disc, Beckman No.
39273 or equivalent
pH meter capable of two-point calibration
Reference Electrode, Ceramic Junction, Calomel,
Corning No. 476002, Beckman No. 38423 or equivalent
(Filled with 3.5 M potassium chloride bridge solution in
outer chamber)
Indicator Electrode, Glass Rugged Bulb, Corning No.
476024 or equivalent
Note: Use pipets and volumetric glassware meeting the
“Class A” definition by the National Institute of Standards
and Technology (NIST).
REAGENTS
Use ACS Reagent Grade reagents unless specified
otherwise.
6 N Sodium Hydroxide, NaOH
0.1% Polystyrene Sulfonate
Ethyl Acetate, water-saturated
Ferroin Indicator
1.0 N Sulfuric Acid, H 2 SO 4
0.05 N Sulfato Cerate, (NH 4 ) 2 Ce(NO 3 ) 6 ,
(standardized to 4 decimal places)
PROCEDURE
Sample Treatment
1. Pour approximately 100 to 120 mL of sample into a
250-mL beaker containing a Teflon-coated stirring
bar.
2. Follow Method ULM-191-2, pH Measurement of
Photographic Processing Solutions, (or any
subsequent pH method) for making high-range pH
measurements.
3. Immerse the electrode assembly in the sample and start
the magnetic stirrer.
4. Adjust the pH of the sample to pH 10.30 ~ 0.03 using
6 N sodium hydroxide. This volume does not have to
be measured.
5. Once the pH has been adjusted, pipes 25.0 mL of the
sample into a 250-mL separatory funnel (No. 1).
6. Add 2 mL of 0.1% polystyrene sulfonate solution and
mix by gently swirling for 10 seconds.
7. Add 25 mL of water-saturated ethyl acetate. Swirl the
funnel for 30 seconds. Stopper the funnel; invert and
vent through the stopcock. Shake separatory funnel
No. 1 horizontally for a few seconds; invert and vent
the funnel through the stopcock. Continue to shake
vigorously for 30 seconds. The funnel should be
vented at least 2 times.
8. Allow the layers to separate. Gently swirling the
funnel will aid breaking up any emulsion at the
aqueous/nonaqueous interface.
9. After separation of the layers occurs, transfer as
completely as possible the lower (aqueous) layer into
another 250-mL separatory funnel (No. 2)
10. Swirl separatory funnel No. 1 and drain any additional
lower (aqueous) layer that separates into separatory
funnel No. 2. Save the top (ethyl acetate) layer in
separatory funnel No. 1.
11. Add 25 mL of water-saturated ethyl acetate to
separatory funnel No. 2. Swirl the funnel for 30
seconds. Stopper the funnel; invert and vent through
the stopcock. Shake the funnel horizontally for a few
seconds; invert and vent through the stopcock.
Continue to shake the funnel vigorously for
30 seconds, venting at least 2 times.
12. After the layers separate, discard the lower (aqueous)
layer as completely as possible. Swirl the funnel and
discard any additional aqueous layer that separates,
taking care not to lose any of the ethyl acetate layer.
13. Transfer the contents of separatory funnel No. 2 (ethyl
acetate layer) into funnel No. 1 (which contains the
first ethyl acetate layer).
2 Processing KODAK Motion Picture Films, Module 3, Analytical Procedures H24.03